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2025-09-19net: Fix null-ptr-deref by sock_lock_init_class_and_name() and rmmod.Kuniyuki Iwashima
[ Upstream commit 0bb2f7a1ad1f11d861f58e5ee5051c8974ff9569 ] When I ran the repro [0] and waited a few seconds, I observed two LOCKDEP splats: a warning immediately followed by a null-ptr-deref. [1] Reproduction Steps: 1) Mount CIFS 2) Add an iptables rule to drop incoming FIN packets for CIFS 3) Unmount CIFS 4) Unload the CIFS module 5) Remove the iptables rule At step 3), the CIFS module calls sock_release() for the underlying TCP socket, and it returns quickly. However, the socket remains in FIN_WAIT_1 because incoming FIN packets are dropped. At this point, the module's refcnt is 0 while the socket is still alive, so the following rmmod command succeeds. # ss -tan State Recv-Q Send-Q Local Address:Port Peer Address:Port FIN-WAIT-1 0 477 10.0.2.15:51062 10.0.0.137:445 # lsmod | grep cifs cifs 1159168 0 This highlights a discrepancy between the lifetime of the CIFS module and the underlying TCP socket. Even after CIFS calls sock_release() and it returns, the TCP socket does not die immediately in order to close the connection gracefully. While this is generally fine, it causes an issue with LOCKDEP because CIFS assigns a different lock class to the TCP socket's sk->sk_lock using sock_lock_init_class_and_name(). Once an incoming packet is processed for the socket or a timer fires, sk->sk_lock is acquired. Then, LOCKDEP checks the lock context in check_wait_context(), where hlock_class() is called to retrieve the lock class. However, since the module has already been unloaded, hlock_class() logs a warning and returns NULL, triggering the null-ptr-deref. If LOCKDEP is enabled, we must ensure that a module calling sock_lock_init_class_and_name() (CIFS, NFS, etc) cannot be unloaded while such a socket is still alive to prevent this issue. Let's hold the module reference in sock_lock_init_class_and_name() and release it when the socket is freed in sk_prot_free(). Note that sock_lock_init() clears sk->sk_owner for svc_create_socket() that calls sock_lock_init_class_and_name() for a listening socket, which clones a socket by sk_clone_lock() without GFP_ZERO. [0]: CIFS_SERVER="10.0.0.137" CIFS_PATH="//${CIFS_SERVER}/Users/Administrator/Desktop/CIFS_TEST" DEV="enp0s3" CRED="/root/WindowsCredential.txt" MNT=$(mktemp -d /tmp/XXXXXX) mount -t cifs ${CIFS_PATH} ${MNT} -o vers=3.0,credentials=${CRED},cache=none,echo_interval=1 iptables -A INPUT -s ${CIFS_SERVER} -j DROP for i in $(seq 10); do umount ${MNT} rmmod cifs sleep 1 done rm -r ${MNT} iptables -D INPUT -s ${CIFS_SERVER} -j DROP [1]: DEBUG_LOCKS_WARN_ON(1) WARNING: CPU: 10 PID: 0 at kernel/locking/lockdep.c:234 hlock_class (kernel/locking/lockdep.c:234 kernel/locking/lockdep.c:223) Modules linked in: cifs_arc4 nls_ucs2_utils cifs_md4 [last unloaded: cifs] CPU: 10 UID: 0 PID: 0 Comm: swapper/10 Not tainted 6.14.0 #36 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 RIP: 0010:hlock_class (kernel/locking/lockdep.c:234 kernel/locking/lockdep.c:223) ... Call Trace: <IRQ> __lock_acquire (kernel/locking/lockdep.c:4853 kernel/locking/lockdep.c:5178) lock_acquire (kernel/locking/lockdep.c:469 kernel/locking/lockdep.c:5853 kernel/locking/lockdep.c:5816) _raw_spin_lock_nested (kernel/locking/spinlock.c:379) tcp_v4_rcv (./include/linux/skbuff.h:1678 ./include/net/tcp.h:2547 net/ipv4/tcp_ipv4.c:2350) ... BUG: kernel NULL pointer dereference, address: 00000000000000c4 PF: supervisor read access in kernel mode PF: error_code(0x0000) - not-present page PGD 0 Oops: Oops: 0000 [#1] PREEMPT SMP NOPTI CPU: 10 UID: 0 PID: 0 Comm: swapper/10 Tainted: G W 6.14.0 #36 Tainted: [W]=WARN Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 RIP: 0010:__lock_acquire (kernel/locking/lockdep.c:4852 kernel/locking/lockdep.c:5178) Code: 15 41 09 c7 41 8b 44 24 20 25 ff 1f 00 00 41 09 c7 8b 84 24 a0 00 00 00 45 89 7c 24 20 41 89 44 24 24 e8 e1 bc ff ff 4c 89 e7 <44> 0f b6 b8 c4 00 00 00 e8 d1 bc ff ff 0f b6 80 c5 00 00 00 88 44 RSP: 0018:ffa0000000468a10 EFLAGS: 00010046 RAX: 0000000000000000 RBX: ff1100010091cc38 RCX: 0000000000000027 RDX: ff1100081f09ca48 RSI: 0000000000000001 RDI: ff1100010091cc88 RBP: ff1100010091c200 R08: ff1100083fe6e228 R09: 00000000ffffbfff R10: ff1100081eca0000 R11: ff1100083fe10dc0 R12: ff1100010091cc88 R13: 0000000000000001 R14: 0000000000000000 R15: 00000000000424b1 FS: 0000000000000000(0000) GS:ff1100081f080000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000000000c4 CR3: 0000000002c4a003 CR4: 0000000000771ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe07f0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: <IRQ> lock_acquire (kernel/locking/lockdep.c:469 kernel/locking/lockdep.c:5853 kernel/locking/lockdep.c:5816) _raw_spin_lock_nested (kernel/locking/spinlock.c:379) tcp_v4_rcv (./include/linux/skbuff.h:1678 ./include/net/tcp.h:2547 net/ipv4/tcp_ipv4.c:2350) ip_protocol_deliver_rcu (net/ipv4/ip_input.c:205 (discriminator 1)) ip_local_deliver_finish (./include/linux/rcupdate.h:878 net/ipv4/ip_input.c:234) ip_sublist_rcv_finish (net/ipv4/ip_input.c:576) ip_list_rcv_finish (net/ipv4/ip_input.c:628) ip_list_rcv (net/ipv4/ip_input.c:670) __netif_receive_skb_list_core (net/core/dev.c:5939 net/core/dev.c:5986) netif_receive_skb_list_internal (net/core/dev.c:6040 net/core/dev.c:6129) napi_complete_done (./include/linux/list.h:37 ./include/net/gro.h:519 ./include/net/gro.h:514 net/core/dev.c:6496) e1000_clean (drivers/net/ethernet/intel/e1000/e1000_main.c:3815) __napi_poll.constprop.0 (net/core/dev.c:7191) net_rx_action (net/core/dev.c:7262 net/core/dev.c:7382) handle_softirqs (kernel/softirq.c:561) __irq_exit_rcu (kernel/softirq.c:596 kernel/softirq.c:435 kernel/softirq.c:662) irq_exit_rcu (kernel/softirq.c:680) common_interrupt (arch/x86/kernel/irq.c:280 (discriminator 14)) </IRQ> <TASK> asm_common_interrupt (./arch/x86/include/asm/idtentry.h:693) RIP: 0010:default_idle (./arch/x86/include/asm/irqflags.h:37 ./arch/x86/include/asm/irqflags.h:92 arch/x86/kernel/process.c:744) Code: 4c 01 c7 4c 29 c2 e9 72 ff ff ff 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa eb 07 0f 00 2d c3 2b 15 00 fb f4 <fa> c3 cc cc cc cc 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 RSP: 0018:ffa00000000ffee8 EFLAGS: 00000202 RAX: 000000000000640b RBX: ff1100010091c200 RCX: 0000000000061aa4 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff812f30c5 RBP: 000000000000000a R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000002 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 ? do_idle (kernel/sched/idle.c:186 kernel/sched/idle.c:325) default_idle_call (./include/linux/cpuidle.h:143 kernel/sched/idle.c:118) do_idle (kernel/sched/idle.c:186 kernel/sched/idle.c:325) cpu_startup_entry (kernel/sched/idle.c:422 (discriminator 1)) start_secondary (arch/x86/kernel/smpboot.c:315) common_startup_64 (arch/x86/kernel/head_64.S:421) </TASK> Modules linked in: cifs_arc4 nls_ucs2_utils cifs_md4 [last unloaded: cifs] CR2: 00000000000000c4 Fixes: ed07536ed673 ("[PATCH] lockdep: annotate nfs/nfsd in-kernel sockets") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20250407163313.22682-1-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> [ Adjust context ] Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-09-04net: rose: convert 'use' field to refcount_tTakamitsu Iwai
[ Upstream commit d860d1faa6b2ce3becfdb8b0c2b048ad31800061 ] The 'use' field in struct rose_neigh is used as a reference counter but lacks atomicity. This can lead to race conditions where a rose_neigh structure is freed while still being referenced by other code paths. For example, when rose_neigh->use becomes zero during an ioctl operation via rose_rt_ioctl(), the structure may be removed while its timer is still active, potentially causing use-after-free issues. This patch changes the type of 'use' from unsigned short to refcount_t and updates all code paths to use rose_neigh_hold() and rose_neigh_put() which operate reference counts atomically. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Takamitsu Iwai <takamitz@amazon.co.jp> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20250823085857.47674-3-takamitz@amazon.co.jp Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-09-04net: rose: split remove and free operations in rose_remove_neigh()Takamitsu Iwai
[ Upstream commit dcb34659028f856c423a29ef9b4e2571d203444d ] The current rose_remove_neigh() performs two distinct operations: 1. Removes rose_neigh from rose_neigh_list 2. Frees the rose_neigh structure Split these operations into separate functions to improve maintainability and prepare for upcoming refcount_t conversion. The timer cleanup remains in rose_remove_neigh() because free operations can be called from timer itself. This patch introduce rose_neigh_put() to handle the freeing of rose_neigh structures and modify rose_remove_neigh() to handle removal only. Signed-off-by: Takamitsu Iwai <takamitz@amazon.co.jp> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20250823085857.47674-2-takamitz@amazon.co.jp Signed-off-by: Jakub Kicinski <kuba@kernel.org> Stable-dep-of: d860d1faa6b2 ("net: rose: convert 'use' field to refcount_t") Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-09-04Bluetooth: hci_sync: fix set_local_name race conditionPavel Shpakovskiy
[ Upstream commit 6bbd0d3f0c23fc53c17409dd7476f38ae0ff0cd9 ] Function set_name_sync() uses hdev->dev_name field to send HCI_OP_WRITE_LOCAL_NAME command, but copying from data to hdev->dev_name is called after mgmt cmd was queued, so it is possible that function set_name_sync() will read old name value. This change adds name as a parameter for function hci_update_name_sync() to avoid race condition. Fixes: 6f6ff38a1e14 ("Bluetooth: hci_sync: Convert MGMT_OP_SET_LOCAL_NAME") Signed-off-by: Pavel Shpakovskiy <pashpakovskii@salutedevices.com> Reviewed-by: Paul Menzel <pmenzel@molgen.mpg.de> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-08-28bonding: Add independent control state machineAahil Awatramani
[ Upstream commit 240fd405528bbf7fafa0559202ca7aa524c9cd96 ] Add support for the independent control state machine per IEEE 802.1AX-2008 5.4.15 in addition to the existing implementation of the coupled control state machine. Introduces two new states, AD_MUX_COLLECTING and AD_MUX_DISTRIBUTING in the LACP MUX state machine for separated handling of an initial Collecting state before the Collecting and Distributing state. This enables a port to be in a state where it can receive incoming packets while not still distributing. This is useful for reducing packet loss when a port begins distributing before its partner is able to collect. Added new functions such as bond_set_slave_tx_disabled_flags and bond_set_slave_rx_enabled_flags to precisely manage the port's collecting and distributing states. Previously, there was no dedicated method to disable TX while keeping RX enabled, which this patch addresses. Note that the regular flow process in the kernel's bonding driver remains unaffected by this patch. The extension requires explicit opt-in by the user (in order to ensure no disruptions for existing setups) via netlink support using the new bonding parameter coupled_control. The default value for coupled_control is set to 1 so as to preserve existing behaviour. Signed-off-by: Aahil Awatramani <aahila@google.com> Reviewed-by: Hangbin Liu <liuhangbin@gmail.com> Link: https://lore.kernel.org/r/20240202175858.1573852-1-aahila@google.com Signed-off-by: Paolo Abeni <pabeni@redhat.com> Stable-dep-of: 0599640a21e9 ("bonding: send LACPDUs periodically in passive mode after receiving partner's LACPDU") Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-08-28bonding: update LACP activity flag after setting lacp_activeHangbin Liu
[ Upstream commit b64d035f77b1f02ab449393342264b44950a75ae ] The port's actor_oper_port_state activity flag should be updated immediately after changing the lacp_active option to reflect the current mode correctly. Fixes: 3a755cd8b7c6 ("bonding: add new option lacp_active") Signed-off-by: Hangbin Liu <liuhangbin@gmail.com> Link: https://patch.msgid.link/20250815062000.22220-2-liuhangbin@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-08-28neighbour: add support for NUD_PERMANENT proxy entriesNicolas Escande
[ Upstream commit c7d78566bbd30544a0618a6ffbc97bc0ddac7035 ] As discussesd before in [0] proxy entries (which are more configuration than runtime data) should stay when the link (carrier) goes does down. This is what happens for regular neighbour entries. So lets fix this by: - storing in proxy entries the fact that it was added as NUD_PERMANENT - not removing NUD_PERMANENT proxy entries when the carrier goes down (same as how it's done in neigh_flush_dev() for regular neigh entries) [0]: https://lore.kernel.org/netdev/c584ef7e-6897-01f3-5b80-12b53f7b4bf4@kernel.org/ Signed-off-by: Nicolas Escande <nico.escande@gmail.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20250617141334.3724863-1-nico.escande@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-08-28wifi: mac80211: don't complete management TX on SAE commitJohannes Berg
[ Upstream commit 6b04716cdcac37bdbacde34def08bc6fdb5fc4e2 ] When SAE commit is sent and received in response, there's no ordering for the SAE confirm messages. As such, don't call drivers to stop listening on the channel when the confirm message is still expected. This fixes an issue if the local confirm is transmitted later than the AP's confirm, for iwlwifi (and possibly mt76) the AP's confirm would then get lost since the device isn't on the channel at the time the AP transmit the confirm. For iwlwifi at least, this also improves the overall timing of the authentication handshake (by about 15ms according to the report), likely since the session protection won't be aborted and rescheduled. Note that even before this, mgd_complete_tx() wasn't always called for each call to mgd_prepare_tx() (e.g. in the case of WEP key shared authentication), and the current drivers that have the complete callback don't seem to mind. Document this as well though. Reported-by: Jan Hendrik Farr <kernel@jfarr.cc> Closes: https://lore.kernel.org/all/aB30Ea2kRG24LINR@archlinux/ Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com> Link: https://patch.msgid.link/20250609213232.12691580e140.I3f1d3127acabcd58348a110ab11044213cf147d3@changeid Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-08-28wifi: cfg80211: Fix interface type validationIlan Peer
[ Upstream commit 14450be2332a49445106403492a367412b8c23f4 ] Fix a condition that verified valid values of interface types. Signed-off-by: Ilan Peer <ilan.peer@intel.com> Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com> Link: https://patch.msgid.link/20250709233537.7ad199ca5939.I0ac1ff74798bf59a87a57f2e18f2153c308b119b@changeid Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-08-15net: drop UFO packets in udp_rcv_segment()Wang Liang
[ Upstream commit d46e51f1c78b9ab9323610feb14238d06d46d519 ] When sending a packet with virtio_net_hdr to tun device, if the gso_type in virtio_net_hdr is SKB_GSO_UDP and the gso_size is less than udphdr size, below crash may happen. ------------[ cut here ]------------ kernel BUG at net/core/skbuff.c:4572! Oops: invalid opcode: 0000 [#1] SMP NOPTI CPU: 0 UID: 0 PID: 62 Comm: mytest Not tainted 6.16.0-rc7 #203 PREEMPT(voluntary) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 RIP: 0010:skb_pull_rcsum+0x8e/0xa0 Code: 00 00 5b c3 cc cc cc cc 8b 93 88 00 00 00 f7 da e8 37 44 38 00 f7 d8 89 83 88 00 00 00 48 8b 83 c8 00 00 00 5b c3 cc cc cc cc <0f> 0b 0f 0b 66 66 2e 0f 1f 84 00 000 RSP: 0018:ffffc900001fba38 EFLAGS: 00000297 RAX: 0000000000000004 RBX: ffff8880040c1000 RCX: ffffc900001fb948 RDX: ffff888003e6d700 RSI: 0000000000000008 RDI: ffff88800411a062 RBP: ffff8880040c1000 R08: 0000000000000000 R09: 0000000000000001 R10: ffff888003606c00 R11: 0000000000000001 R12: 0000000000000000 R13: ffff888004060900 R14: ffff888004050000 R15: ffff888004060900 FS: 000000002406d3c0(0000) GS:ffff888084a19000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020000040 CR3: 0000000004007000 CR4: 00000000000006f0 Call Trace: <TASK> udp_queue_rcv_one_skb+0x176/0x4b0 net/ipv4/udp.c:2445 udp_queue_rcv_skb+0x155/0x1f0 net/ipv4/udp.c:2475 udp_unicast_rcv_skb+0x71/0x90 net/ipv4/udp.c:2626 __udp4_lib_rcv+0x433/0xb00 net/ipv4/udp.c:2690 ip_protocol_deliver_rcu+0xa6/0x160 net/ipv4/ip_input.c:205 ip_local_deliver_finish+0x72/0x90 net/ipv4/ip_input.c:233 ip_sublist_rcv_finish+0x5f/0x70 net/ipv4/ip_input.c:579 ip_sublist_rcv+0x122/0x1b0 net/ipv4/ip_input.c:636 ip_list_rcv+0xf7/0x130 net/ipv4/ip_input.c:670 __netif_receive_skb_list_core+0x21d/0x240 net/core/dev.c:6067 netif_receive_skb_list_internal+0x186/0x2b0 net/core/dev.c:6210 napi_complete_done+0x78/0x180 net/core/dev.c:6580 tun_get_user+0xa63/0x1120 drivers/net/tun.c:1909 tun_chr_write_iter+0x65/0xb0 drivers/net/tun.c:1984 vfs_write+0x300/0x420 fs/read_write.c:593 ksys_write+0x60/0xd0 fs/read_write.c:686 do_syscall_64+0x50/0x1c0 arch/x86/entry/syscall_64.c:63 </TASK> To trigger gso segment in udp_queue_rcv_skb(), we should also set option UDP_ENCAP_ESPINUDP to enable udp_sk(sk)->encap_rcv. When the encap_rcv hook return 1 in udp_queue_rcv_one_skb(), udp_csum_pull_header() will try to pull udphdr, but the skb size has been segmented to gso size, which leads to this crash. Previous commit cf329aa42b66 ("udp: cope with UDP GRO packet misdirection") introduces segmentation in UDP receive path only for GRO, which was never intended to be used for UFO, so drop UFO packets in udp_rcv_segment(). Link: https://lore.kernel.org/netdev/20250724083005.3918375-1-wangliang74@huawei.com/ Link: https://lore.kernel.org/netdev/20250729123907.3318425-1-wangliang74@huawei.com/ Fixes: cf329aa42b66 ("udp: cope with UDP GRO packet misdirection") Suggested-by: Willem de Bruijn <willemdebruijn.kernel@gmail.com> Signed-off-by: Wang Liang <wangliang74@huawei.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/20250730101458.3470788-1-wangliang74@huawei.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-08-15net_sched: act_ctinfo: use atomic64_t for three countersEric Dumazet
[ Upstream commit d300335b4e18672913dd792ff9f49e6cccf41d26 ] Commit 21c167aa0ba9 ("net/sched: act_ctinfo: use percpu stats") missed that stats_dscp_set, stats_dscp_error and stats_cpmark_set might be written (and read) locklessly. Use atomic64_t for these three fields, I doubt act_ctinfo is used heavily on big SMP hosts anyway. Fixes: 24ec483cec98 ("net: sched: Introduce act_ctinfo action") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Pedro Tammela <pctammela@mojatatu.com> Link: https://patch.msgid.link/20250709090204.797558-6-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-07-24netfilter: nf_conntrack: fix crash due to removal of uninitialised entryFlorian Westphal
[ Upstream commit 2d72afb340657f03f7261e9243b44457a9228ac7 ] A crash in conntrack was reported while trying to unlink the conntrack entry from the hash bucket list: [exception RIP: __nf_ct_delete_from_lists+172] [..] #7 [ff539b5a2b043aa0] nf_ct_delete at ffffffffc124d421 [nf_conntrack] #8 [ff539b5a2b043ad0] nf_ct_gc_expired at ffffffffc124d999 [nf_conntrack] #9 [ff539b5a2b043ae0] __nf_conntrack_find_get at ffffffffc124efbc [nf_conntrack] [..] The nf_conn struct is marked as allocated from slab but appears to be in a partially initialised state: ct hlist pointer is garbage; looks like the ct hash value (hence crash). ct->status is equal to IPS_CONFIRMED|IPS_DYING, which is expected ct->timeout is 30000 (=30s), which is unexpected. Everything else looks like normal udp conntrack entry. If we ignore ct->status and pretend its 0, the entry matches those that are newly allocated but not yet inserted into the hash: - ct hlist pointers are overloaded and store/cache the raw tuple hash - ct->timeout matches the relative time expected for a new udp flow rather than the absolute 'jiffies' value. If it were not for the presence of IPS_CONFIRMED, __nf_conntrack_find_get() would have skipped the entry. Theory is that we did hit following race: cpu x cpu y cpu z found entry E found entry E E is expired <preemption> nf_ct_delete() return E to rcu slab init_conntrack E is re-inited, ct->status set to 0 reply tuplehash hnnode.pprev stores hash value. cpu y found E right before it was deleted on cpu x. E is now re-inited on cpu z. cpu y was preempted before checking for expiry and/or confirm bit. ->refcnt set to 1 E now owned by skb ->timeout set to 30000 If cpu y were to resume now, it would observe E as expired but would skip E due to missing CONFIRMED bit. nf_conntrack_confirm gets called sets: ct->status |= CONFIRMED This is wrong: E is not yet added to hashtable. cpu y resumes, it observes E as expired but CONFIRMED: <resumes> nf_ct_expired() -> yes (ct->timeout is 30s) confirmed bit set. cpu y will try to delete E from the hashtable: nf_ct_delete() -> set DYING bit __nf_ct_delete_from_lists Even this scenario doesn't guarantee a crash: cpu z still holds the table bucket lock(s) so y blocks: wait for spinlock held by z CONFIRMED is set but there is no guarantee ct will be added to hash: "chaintoolong" or "clash resolution" logic both skip the insert step. reply hnnode.pprev still stores the hash value. unlocks spinlock return NF_DROP <unblocks, then crashes on hlist_nulls_del_rcu pprev> In case CPU z does insert the entry into the hashtable, cpu y will unlink E again right away but no crash occurs. Without 'cpu y' race, 'garbage' hlist is of no consequence: ct refcnt remains at 1, eventually skb will be free'd and E gets destroyed via: nf_conntrack_put -> nf_conntrack_destroy -> nf_ct_destroy. To resolve this, move the IPS_CONFIRMED assignment after the table insertion but before the unlock. Pablo points out that the confirm-bit-store could be reordered to happen before hlist add resp. the timeout fixup, so switch to set_bit and before_atomic memory barrier to prevent this. It doesn't matter if other CPUs can observe a newly inserted entry right before the CONFIRMED bit was set: Such event cannot be distinguished from above "E is the old incarnation" case: the entry will be skipped. Also change nf_ct_should_gc() to first check the confirmed bit. The gc sequence is: 1. Check if entry has expired, if not skip to next entry 2. Obtain a reference to the expired entry. 3. Call nf_ct_should_gc() to double-check step 1. nf_ct_should_gc() is thus called only for entries that already failed an expiry check. After this patch, once the confirmed bit check passes ct->timeout has been altered to reflect the absolute 'best before' date instead of a relative time. Step 3 will therefore not remove the entry. Without this change to nf_ct_should_gc() we could still get this sequence: 1. Check if entry has expired. 2. Obtain a reference. 3. Call nf_ct_should_gc() to double-check step 1: 4 - entry is still observed as expired 5 - meanwhile, ct->timeout is corrected to absolute value on other CPU and confirm bit gets set 6 - confirm bit is seen 7 - valid entry is removed again First do check 6), then 4) so the gc expiry check always picks up either confirmed bit unset (entry gets skipped) or expiry re-check failure for re-inited conntrack objects. This change cannot be backported to releases before 5.19. Without commit 8a75a2c17410 ("netfilter: conntrack: remove unconfirmed list") |= IPS_CONFIRMED line cannot be moved without further changes. Cc: Razvan Cojocaru <rzvncj@gmail.com> Link: https://lore.kernel.org/netfilter-devel/20250627142758.25664-1-fw@strlen.de/ Link: https://lore.kernel.org/netfilter-devel/4239da15-83ff-4ca4-939d-faef283471bb@gmail.com/ Fixes: 1397af5bfd7d ("netfilter: conntrack: remove the percpu dying list") Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-07-17netfilter: flowtable: account for Ethernet header in nf_flow_pppoe_proto()Eric Dumazet
[ Upstream commit 18cdb3d982da8976b28d57691eb256ec5688fad2 ] syzbot found a potential access to uninit-value in nf_flow_pppoe_proto() Blamed commit forgot the Ethernet header. BUG: KMSAN: uninit-value in nf_flow_offload_inet_hook+0x7e4/0x940 net/netfilter/nf_flow_table_inet.c:27 nf_flow_offload_inet_hook+0x7e4/0x940 net/netfilter/nf_flow_table_inet.c:27 nf_hook_entry_hookfn include/linux/netfilter.h:157 [inline] nf_hook_slow+0xe1/0x3d0 net/netfilter/core.c:623 nf_hook_ingress include/linux/netfilter_netdev.h:34 [inline] nf_ingress net/core/dev.c:5742 [inline] __netif_receive_skb_core+0x4aff/0x70c0 net/core/dev.c:5837 __netif_receive_skb_one_core net/core/dev.c:5975 [inline] __netif_receive_skb+0xcc/0xac0 net/core/dev.c:6090 netif_receive_skb_internal net/core/dev.c:6176 [inline] netif_receive_skb+0x57/0x630 net/core/dev.c:6235 tun_rx_batched+0x1df/0x980 drivers/net/tun.c:1485 tun_get_user+0x4ee0/0x6b40 drivers/net/tun.c:1938 tun_chr_write_iter+0x3e9/0x5c0 drivers/net/tun.c:1984 new_sync_write fs/read_write.c:593 [inline] vfs_write+0xb4b/0x1580 fs/read_write.c:686 ksys_write fs/read_write.c:738 [inline] __do_sys_write fs/read_write.c:749 [inline] Reported-by: syzbot+bf6ed459397e307c3ad2@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/686bc073.a00a0220.c7b3.0086.GAE@google.com/T/#u Fixes: 87b3593bed18 ("netfilter: flowtable: validate pppoe header") Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Pablo Neira Ayuso <pablo@netfilter.org> Link: https://patch.msgid.link/20250707124517.614489-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-06-27net: Fix checksum update for ILA adj-transportPaul Chaignon
commit 6043b794c7668c19dabc4a93c75b924a19474d59 upstream. During ILA address translations, the L4 checksums can be handled in different ways. One of them, adj-transport, consist in parsing the transport layer and updating any found checksum. This logic relies on inet_proto_csum_replace_by_diff and produces an incorrect skb->csum when in state CHECKSUM_COMPLETE. This bug can be reproduced with a simple ILA to SIR mapping, assuming packets are received with CHECKSUM_COMPLETE: $ ip a show dev eth0 14: eth0@if15: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000 link/ether 62:ae:35:9e:0f:8d brd ff:ff:ff:ff:ff:ff link-netnsid 0 inet6 3333:0:0:1::c078/64 scope global valid_lft forever preferred_lft forever inet6 fd00:10:244:1::c078/128 scope global nodad valid_lft forever preferred_lft forever inet6 fe80::60ae:35ff:fe9e:f8d/64 scope link proto kernel_ll valid_lft forever preferred_lft forever $ ip ila add loc_match fd00:10:244:1 loc 3333:0:0:1 \ csum-mode adj-transport ident-type luid dev eth0 Then I hit [fd00:10:244:1::c078]:8000 with a server listening only on [3333:0:0:1::c078]:8000. With the bug, the SYN packet is dropped with SKB_DROP_REASON_TCP_CSUM after inet_proto_csum_replace_by_diff changed skb->csum. The translation and drop are visible on pwru [1] traces: IFACE TUPLE FUNC eth0:9 [fd00:10:244:3::3d8]:51420->[fd00:10:244:1::c078]:8000(tcp) ipv6_rcv eth0:9 [fd00:10:244:3::3d8]:51420->[fd00:10:244:1::c078]:8000(tcp) ip6_rcv_core eth0:9 [fd00:10:244:3::3d8]:51420->[fd00:10:244:1::c078]:8000(tcp) nf_hook_slow eth0:9 [fd00:10:244:3::3d8]:51420->[fd00:10:244:1::c078]:8000(tcp) inet_proto_csum_replace_by_diff eth0:9 [fd00:10:244:3::3d8]:51420->[3333:0:0:1::c078]:8000(tcp) tcp_v6_early_demux eth0:9 [fd00:10:244:3::3d8]:51420->[3333:0:0:1::c078]:8000(tcp) ip6_route_input eth0:9 [fd00:10:244:3::3d8]:51420->[3333:0:0:1::c078]:8000(tcp) ip6_input eth0:9 [fd00:10:244:3::3d8]:51420->[3333:0:0:1::c078]:8000(tcp) ip6_input_finish eth0:9 [fd00:10:244:3::3d8]:51420->[3333:0:0:1::c078]:8000(tcp) ip6_protocol_deliver_rcu eth0:9 [fd00:10:244:3::3d8]:51420->[3333:0:0:1::c078]:8000(tcp) raw6_local_deliver eth0:9 [fd00:10:244:3::3d8]:51420->[3333:0:0:1::c078]:8000(tcp) ipv6_raw_deliver eth0:9 [fd00:10:244:3::3d8]:51420->[3333:0:0:1::c078]:8000(tcp) tcp_v6_rcv eth0:9 [fd00:10:244:3::3d8]:51420->[3333:0:0:1::c078]:8000(tcp) __skb_checksum_complete eth0:9 [fd00:10:244:3::3d8]:51420->[3333:0:0:1::c078]:8000(tcp) kfree_skb_reason(SKB_DROP_REASON_TCP_CSUM) eth0:9 [fd00:10:244:3::3d8]:51420->[3333:0:0:1::c078]:8000(tcp) skb_release_head_state eth0:9 [fd00:10:244:3::3d8]:51420->[3333:0:0:1::c078]:8000(tcp) skb_release_data eth0:9 [fd00:10:244:3::3d8]:51420->[3333:0:0:1::c078]:8000(tcp) skb_free_head eth0:9 [fd00:10:244:3::3d8]:51420->[3333:0:0:1::c078]:8000(tcp) kfree_skbmem This is happening because inet_proto_csum_replace_by_diff is updating skb->csum when it shouldn't. The L4 checksum is updated such that it "cancels" the IPv6 address change in terms of checksum computation, so the impact on skb->csum is null. Note this would be different for an IPv4 packet since three fields would be updated: the IPv4 address, the IP checksum, and the L4 checksum. Two would cancel each other and skb->csum would still need to be updated to take the L4 checksum change into account. This patch fixes it by passing an ipv6 flag to inet_proto_csum_replace_by_diff, to skip the skb->csum update if we're in the IPv6 case. Note the behavior of the only other user of inet_proto_csum_replace_by_diff, the BPF subsystem, is left as is in this patch and fixed in the subsequent patch. With the fix, using the reproduction from above, I can confirm skb->csum is not touched by inet_proto_csum_replace_by_diff and the TCP SYN proceeds to the application after the ILA translation. Link: https://github.com/cilium/pwru [1] Fixes: 65d7ab8de582 ("net: Identifier Locator Addressing module") Signed-off-by: Paul Chaignon <paul.chaignon@gmail.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://patch.msgid.link/b5539869e3550d46068504feb02d37653d939c0b.1748509484.git.paul.chaignon@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Paul Chaignon <paul.chaignon@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-06-27net: Fix TOCTOU issue in sk_is_readable()Michal Luczaj
[ Upstream commit 2660a544fdc0940bba15f70508a46cf9a6491230 ] sk->sk_prot->sock_is_readable is a valid function pointer when sk resides in a sockmap. After the last sk_psock_put() (which usually happens when socket is removed from sockmap), sk->sk_prot gets restored and sk->sk_prot->sock_is_readable becomes NULL. This makes sk_is_readable() racy, if the value of sk->sk_prot is reloaded after the initial check. Which in turn may lead to a null pointer dereference. Ensure the function pointer does not turn NULL after the check. Fixes: 8934ce2fd081 ("bpf: sockmap redirect ingress support") Suggested-by: Jakub Sitnicki <jakub@cloudflare.com> Signed-off-by: Michal Luczaj <mhal@rbox.co> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/20250609-skisreadable-toctou-v1-1-d0dfb2d62c37@rbox.co Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-06-27Bluetooth: MGMT: Fix UAF on mgmt_remove_adv_monitor_completeLuiz Augusto von Dentz
[ Upstream commit e6ed54e86aae9e4f7286ce8d5c73780f91b48d1c ] This reworks MGMT_OP_REMOVE_ADV_MONITOR to not use mgmt_pending_add to avoid crashes like bellow: ================================================================== BUG: KASAN: slab-use-after-free in mgmt_remove_adv_monitor_complete+0xe5/0x540 net/bluetooth/mgmt.c:5406 Read of size 8 at addr ffff88801c53f318 by task kworker/u5:5/5341 CPU: 0 UID: 0 PID: 5341 Comm: kworker/u5:5 Not tainted 6.15.0-syzkaller-10402-g4cb6c8af8591 #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Workqueue: hci0 hci_cmd_sync_work Call Trace: <TASK> dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:408 [inline] print_report+0xd2/0x2b0 mm/kasan/report.c:521 kasan_report+0x118/0x150 mm/kasan/report.c:634 mgmt_remove_adv_monitor_complete+0xe5/0x540 net/bluetooth/mgmt.c:5406 hci_cmd_sync_work+0x261/0x3a0 net/bluetooth/hci_sync.c:334 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3321 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402 kthread+0x711/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 </TASK> Allocated by task 5987: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:260 [inline] __kmalloc_cache_noprof+0x230/0x3d0 mm/slub.c:4358 kmalloc_noprof include/linux/slab.h:905 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] mgmt_pending_new+0x65/0x240 net/bluetooth/mgmt_util.c:252 mgmt_pending_add+0x34/0x120 net/bluetooth/mgmt_util.c:279 remove_adv_monitor+0x103/0x1b0 net/bluetooth/mgmt.c:5454 hci_mgmt_cmd+0x9c9/0xef0 net/bluetooth/hci_sock.c:1719 hci_sock_sendmsg+0x6ca/0xef0 net/bluetooth/hci_sock.c:1839 sock_sendmsg_nosec net/socket.c:712 [inline] __sock_sendmsg+0x219/0x270 net/socket.c:727 sock_write_iter+0x258/0x330 net/socket.c:1131 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x548/0xa90 fs/read_write.c:686 ksys_write+0x145/0x250 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 5989: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x62/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2380 [inline] slab_free mm/slub.c:4642 [inline] kfree+0x18e/0x440 mm/slub.c:4841 mgmt_pending_foreach+0xc9/0x120 net/bluetooth/mgmt_util.c:242 mgmt_index_removed+0x10d/0x2f0 net/bluetooth/mgmt.c:9366 hci_sock_bind+0xbe9/0x1000 net/bluetooth/hci_sock.c:1314 __sys_bind_socket net/socket.c:1810 [inline] __sys_bind+0x2c3/0x3e0 net/socket.c:1841 __do_sys_bind net/socket.c:1846 [inline] __se_sys_bind net/socket.c:1844 [inline] __x64_sys_bind+0x7a/0x90 net/socket.c:1844 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Fixes: 66bd095ab5d4 ("Bluetooth: advmon offload MSFT remove monitor") Closes: https://syzkaller.appspot.com/bug?extid=feb0dc579bbe30a13190 Reported-by: syzbot+feb0dc579bbe30a13190@syzkaller.appspotmail.com Tested-by: syzbot+feb0dc579bbe30a13190@syzkaller.appspotmail.com Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-06-04af_unix: Add dead flag to struct scm_fp_list.Kuniyuki Iwashima
commit 7172dc93d621d5dc302d007e95ddd1311ec64283 upstream. Commit 1af2dface5d2 ("af_unix: Don't access successor in unix_del_edges() during GC.") fixed use-after-free by avoid accessing edge->successor while GC is in progress. However, there could be a small race window where another process could call unix_del_edges() while gc_in_progress is true and __skb_queue_purge() is on the way. So, we need another marker for struct scm_fp_list which indicates if the skb is garbage-collected. This patch adds dead flag in struct scm_fp_list and set it true before calling __skb_queue_purge(). Fixes: 1af2dface5d2 ("af_unix: Don't access successor in unix_del_edges() during GC.") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Acked-by: Paolo Abeni <pabeni@redhat.com> Link: https://lore.kernel.org/r/20240508171150.50601-1-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Lee Jones <lee@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-06-04af_unix: Try not to hold unix_gc_lock during accept().Kuniyuki Iwashima
commit fd86344823b521149bb31d91eba900ba3525efa6 upstream. Commit dcf70df2048d ("af_unix: Fix up unix_edge.successor for embryo socket.") added spin_lock(&unix_gc_lock) in accept() path, and it caused regression in a stress test as reported by kernel test robot. If the embryo socket is not part of the inflight graph, we need not hold the lock. To decide that in O(1) time and avoid the regression in the normal use case, 1. add a new stat unix_sk(sk)->scm_stat.nr_unix_fds 2. count the number of inflight AF_UNIX sockets in the receive queue under unix_state_lock() 3. move unix_update_edges() call under unix_state_lock() 4. avoid locking if nr_unix_fds is 0 in unix_update_edges() Reported-by: kernel test robot <oliver.sang@intel.com> Closes: https://lore.kernel.org/oe-lkp/202404101427.92a08551-oliver.sang@intel.com Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://lore.kernel.org/r/20240413021928.20946-1-kuniyu@amazon.com Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Lee Jones <lee@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-06-04af_unix: Remove lock dance in unix_peek_fds().Kuniyuki Iwashima
commit 118f457da9ed58a79e24b73c2ef0aa1987241f0e upstream. In the previous GC implementation, the shape of the inflight socket graph was not expected to change while GC was in progress. MSG_PEEK was tricky because it could install inflight fd silently and transform the graph. Let's say we peeked a fd, which was a listening socket, and accept()ed some embryo sockets from it. The garbage collection algorithm would have been confused because the set of sockets visited in scan_inflight() would change within the same GC invocation. That's why we placed spin_lock(&unix_gc_lock) and spin_unlock() in unix_peek_fds() with a fat comment. In the new GC implementation, we no longer garbage-collect the socket if it exists in another queue, that is, if it has a bridge to another SCC. Also, accept() will require the lock if it has edges. Thus, we need not do the complicated lock dance. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://lore.kernel.org/r/20240401173125.92184-3-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Lee Jones <lee@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-06-04af_unix: Replace garbage collection algorithm.Kuniyuki Iwashima
commit 4090fa373f0e763c43610853d2774b5979915959 upstream. If we find a dead SCC during iteration, we call unix_collect_skb() to splice all skb in the SCC to the global sk_buff_head, hitlist. After iterating all SCC, we unlock unix_gc_lock and purge the queue. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Acked-by: Paolo Abeni <pabeni@redhat.com> Link: https://lore.kernel.org/r/20240325202425.60930-15-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Lee Jones <lee@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-06-04af_unix: Assign a unique index to SCC.Kuniyuki Iwashima
commit bfdb01283ee8f2f3089656c3ff8f62bb072dabb2 upstream. The definition of the lowlink in Tarjan's algorithm is the smallest index of a vertex that is reachable with at most one back-edge in SCC. This is not useful for a cross-edge. If we start traversing from A in the following graph, the final lowlink of D is 3. The cross-edge here is one between D and C. A -> B -> D D = (4, 3) (index, lowlink) ^ | | C = (3, 1) | V | B = (2, 1) `--- C <--' A = (1, 1) This is because the lowlink of D is updated with the index of C. In the following patch, we detect a dead SCC by checking two conditions for each vertex. 1) vertex has no edge directed to another SCC (no bridge) 2) vertex's out_degree is the same as the refcount of its file If 1) is false, there is a receiver of all fds of the SCC and its ancestor SCC. To evaluate 1), we need to assign a unique index to each SCC and assign it to all vertices in the SCC. This patch changes the lowlink update logic for cross-edge so that in the example above, the lowlink of D is updated with the lowlink of C. A -> B -> D D = (4, 1) (index, lowlink) ^ | | C = (3, 1) | V | B = (2, 1) `--- C <--' A = (1, 1) Then, all vertices in the same SCC have the same lowlink, and we can quickly find the bridge connecting to different SCC if exists. However, it is no longer called lowlink, so we rename it to scc_index. (It's sometimes called lowpoint.) Also, we add a global variable to hold the last index used in DFS so that we do not reset the initial index in each DFS. This patch can be squashed to the SCC detection patch but is split deliberately for anyone wondering why lowlink is not used as used in the original Tarjan's algorithm and many reference implementations. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Acked-by: Paolo Abeni <pabeni@redhat.com> Link: https://lore.kernel.org/r/20240325202425.60930-13-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Lee Jones <lee@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-06-04af_unix: Save O(n) setup of Tarjan's algo.Kuniyuki Iwashima
commit ba31b4a4e1018f5844c6eb31734976e2184f2f9a upstream. Before starting Tarjan's algorithm, we need to mark all vertices as unvisited. We can save this O(n) setup by reserving two special indices (0, 1) and using two variables. The first time we link a vertex to unix_unvisited_vertices, we set unix_vertex_unvisited_index to index. During DFS, we can see that the index of unvisited vertices is the same as unix_vertex_unvisited_index. When we finalise SCC later, we set unix_vertex_grouped_index to each vertex's index. Then, we can know (i) that the vertex is on the stack if the index of a visited vertex is >= 2 and (ii) that it is not on the stack and belongs to a different SCC if the index is unix_vertex_grouped_index. After the whole algorithm, all indices of vertices are set as unix_vertex_grouped_index. Next time we start DFS, we know that all unvisited vertices have unix_vertex_grouped_index, and we can use unix_vertex_unvisited_index as the not-on-stack marker. To use the same variable in __unix_walk_scc(), we can swap unix_vertex_(grouped|unvisited)_index at the end of Tarjan's algorithm. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Acked-by: Paolo Abeni <pabeni@redhat.com> Link: https://lore.kernel.org/r/20240325202425.60930-10-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Lee Jones <lee@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-06-04af_unix: Fix up unix_edge.successor for embryo socket.Kuniyuki Iwashima
commit dcf70df2048d27c5d186f013f101a4aefd63aa41 upstream. To garbage collect inflight AF_UNIX sockets, we must define the cyclic reference appropriately. This is a bit tricky if the loop consists of embryo sockets. Suppose that the fd of AF_UNIX socket A is passed to D and the fd B to C and that C and D are embryo sockets of A and B, respectively. It may appear that there are two separate graphs, A (-> D) and B (-> C), but this is not correct. A --. .-- B X C <-' `-> D Now, D holds A's refcount, and C has B's refcount, so unix_release() will never be called for A and B when we close() them. However, no one can call close() for D and C to free skbs holding refcounts of A and B because C/D is in A/B's receive queue, which should have been purged by unix_release() for A and B. So, here's another type of cyclic reference. When a fd of an AF_UNIX socket is passed to an embryo socket, the reference is indirectly held by its parent listening socket. .-> A .-> B | `- sk_receive_queue | `- sk_receive_queue | `- skb | `- skb | `- sk == C | `- sk == D | `- sk_receive_queue | `- sk_receive_queue | `- skb +---------' `- skb +-. | | `---------------------------------------------------------' Technically, the graph must be denoted as A <-> B instead of A (-> D) and B (-> C) to find such a cyclic reference without touching each socket's receive queue. .-> A --. .-- B <-. | X | == A <-> B `-- C <-' `-> D --' We apply this fixup during GC by fetching the real successor by unix_edge_successor(). When we call accept(), we clear unix_sock.listener under unix_gc_lock not to confuse GC. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Acked-by: Paolo Abeni <pabeni@redhat.com> Link: https://lore.kernel.org/r/20240325202425.60930-9-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Lee Jones <lee@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-06-04af_unix: Save listener for embryo socket.Kuniyuki Iwashima
commit aed6ecef55d70de3762ce41c561b7f547dbaf107 upstream. This is a prep patch for the following change, where we need to fetch the listening socket from the successor embryo socket during GC. We add a new field to struct unix_sock to save a pointer to a listening socket. We set it when connect() creates a new socket, and clear it when accept() is called. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Acked-by: Paolo Abeni <pabeni@redhat.com> Link: https://lore.kernel.org/r/20240325202425.60930-8-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Lee Jones <lee@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-06-04af_unix: Detect Strongly Connected Components.Kuniyuki Iwashima
commit 3484f063172dd88776b062046d721d7c2ae1af7c upstream. In the new GC, we use a simple graph algorithm, Tarjan's Strongly Connected Components (SCC) algorithm, to find cyclic references. The algorithm visits every vertex exactly once using depth-first search (DFS). DFS starts by pushing an input vertex to a stack and assigning it a unique number. Two fields, index and lowlink, are initialised with the number, but lowlink could be updated later during DFS. If a vertex has an edge to an unvisited inflight vertex, we visit it and do the same processing. So, we will have vertices in the stack in the order they appear and number them consecutively in the same order. If a vertex has a back-edge to a visited vertex in the stack, we update the predecessor's lowlink with the successor's index. After iterating edges from the vertex, we check if its index equals its lowlink. If the lowlink is different from the index, it shows there was a back-edge. Then, we go backtracking and propagate the lowlink to its predecessor and resume the previous edge iteration from the next edge. If the lowlink is the same as the index, we pop vertices before and including the vertex from the stack. Then, the set of vertices is SCC, possibly forming a cycle. At the same time, we move the vertices to unix_visited_vertices. When we finish the algorithm, all vertices in each SCC will be linked via unix_vertex.scc_entry. Let's take an example. We have a graph including five inflight vertices (F is not inflight): A -> B -> C -> D -> E (-> F) ^ | `---------' Suppose that we start DFS from C. We will visit C, D, and B first and initialise their index and lowlink. Then, the stack looks like this: > B = (3, 3) (index, lowlink) D = (2, 2) C = (1, 1) When checking B's edge to C, we update B's lowlink with C's index and propagate it to D. B = (3, 1) (index, lowlink) > D = (2, 1) C = (1, 1) Next, we visit E, which has no edge to an inflight vertex. > E = (4, 4) (index, lowlink) B = (3, 1) D = (2, 1) C = (1, 1) When we leave from E, its index and lowlink are the same, so we pop E from the stack as single-vertex SCC. Next, we leave from B and D but do nothing because their lowlink are different from their index. B = (3, 1) (index, lowlink) D = (2, 1) > C = (1, 1) Then, we leave from C, whose index and lowlink are the same, so we pop B, D and C as SCC. Last, we do DFS for the rest of vertices, A, which is also a single-vertex SCC. Finally, each unix_vertex.scc_entry is linked as follows: A -. B -> C -> D E -. ^ | ^ | ^ | `--' `---------' `--' We use SCC later to decide whether we can garbage-collect the sockets. Note that we still cannot detect SCC properly if an edge points to an embryo socket. The following two patches will sort it out. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Acked-by: Paolo Abeni <pabeni@redhat.com> Link: https://lore.kernel.org/r/20240325202425.60930-7-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Lee Jones <lee@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-06-04af_unix: Iterate all vertices by DFS.Kuniyuki Iwashima
commit 6ba76fd2848e107594ea4f03b737230f74bc23ea upstream. The new GC will use a depth first search graph algorithm to find cyclic references. The algorithm visits every vertex exactly once. Here, we implement the DFS part without recursion so that no one can abuse it. unix_walk_scc() marks every vertex unvisited by initialising index as UNIX_VERTEX_INDEX_UNVISITED and iterates inflight vertices in unix_unvisited_vertices and call __unix_walk_scc() to start DFS from an arbitrary vertex. __unix_walk_scc() iterates all edges starting from the vertex and explores the neighbour vertices with DFS using edge_stack. After visiting all neighbours, __unix_walk_scc() moves the visited vertex to unix_visited_vertices so that unix_walk_scc() will not restart DFS from the visited vertex. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Acked-by: Paolo Abeni <pabeni@redhat.com> Link: https://lore.kernel.org/r/20240325202425.60930-6-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Lee Jones <lee@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-06-04af_unix: Link struct unix_edge when queuing skb.Kuniyuki Iwashima
commit 42f298c06b30bfe0a8cbee5d38644e618699e26e upstream. Just before queuing skb with inflight fds, we call scm_stat_add(), which is a good place to set up the preallocated struct unix_vertex and struct unix_edge in UNIXCB(skb).fp. Then, we call unix_add_edges() and construct the directed graph as follows: 1. Set the inflight socket's unix_sock to unix_edge.predecessor. 2. Set the receiver's unix_sock to unix_edge.successor. 3. Set the preallocated vertex to inflight socket's unix_sock.vertex. 4. Link inflight socket's unix_vertex.entry to unix_unvisited_vertices. 5. Link unix_edge.vertex_entry to the inflight socket's unix_vertex.edges. Let's say we pass the fd of AF_UNIX socket A to B and the fd of B to C. The graph looks like this: +-------------------------+ | unix_unvisited_vertices | <-------------------------. +-------------------------+ | + | | +--------------+ +--------------+ | +--------------+ | | unix_sock A | <---. .---> | unix_sock B | <-|-. .---> | unix_sock C | | +--------------+ | | +--------------+ | | | +--------------+ | .-+ | vertex | | | .-+ | vertex | | | | | vertex | | | +--------------+ | | | +--------------+ | | | +--------------+ | | | | | | | | | | +--------------+ | | | +--------------+ | | | | '-> | unix_vertex | | | '-> | unix_vertex | | | | | +--------------+ | | +--------------+ | | | `---> | entry | +---------> | entry | +-' | | |--------------| | | |--------------| | | | edges | <-. | | | edges | <-. | | +--------------+ | | | +--------------+ | | | | | | | | | .----------------------' | | .----------------------' | | | | | | | | | +--------------+ | | | +--------------+ | | | | unix_edge | | | | | unix_edge | | | | +--------------+ | | | +--------------+ | | `-> | vertex_entry | | | `-> | vertex_entry | | | |--------------| | | |--------------| | | | predecessor | +---' | | predecessor | +---' | |--------------| | |--------------| | | successor | +-----' | successor | +-----' +--------------+ +--------------+ Henceforth, we denote such a graph as A -> B (-> C). Now, we can express all inflight fd graphs that do not contain embryo sockets. We will support the particular case later. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Acked-by: Paolo Abeni <pabeni@redhat.com> Link: https://lore.kernel.org/r/20240325202425.60930-4-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Lee Jones <lee@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-06-04af_unix: Allocate struct unix_edge for each inflight AF_UNIX fd.Kuniyuki Iwashima
commit 29b64e354029cfcf1eea4d91b146c7b769305930 upstream. As with the previous patch, we preallocate to skb's scm_fp_list an array of struct unix_edge in the number of inflight AF_UNIX fds. There we just preallocate memory and do not use immediately because sendmsg() could fail after this point. The actual use will be in the next patch. When we queue skb with inflight edges, we will set the inflight socket's unix_sock as unix_edge->predecessor and the receiver's unix_sock as successor, and then we will link the edge to the inflight socket's unix_vertex.edges. Note that we set NULL to cloned scm_fp_list.edges in scm_fp_dup() so that MSG_PEEK does not change the shape of the directed graph. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Acked-by: Paolo Abeni <pabeni@redhat.com> Link: https://lore.kernel.org/r/20240325202425.60930-3-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Lee Jones <lee@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-06-04af_unix: Allocate struct unix_vertex for each inflight AF_UNIX fd.Kuniyuki Iwashima
commit 1fbfdfaa590248c1d86407f578e40e5c65136330 upstream. We will replace the garbage collection algorithm for AF_UNIX, where we will consider each inflight AF_UNIX socket as a vertex and its file descriptor as an edge in a directed graph. This patch introduces a new struct unix_vertex representing a vertex in the graph and adds its pointer to struct unix_sock. When we send a fd using the SCM_RIGHTS message, we allocate struct scm_fp_list to struct scm_cookie in scm_fp_copy(). Then, we bump each refcount of the inflight fds' struct file and save them in scm_fp_list.fp. After that, unix_attach_fds() inexplicably clones scm_fp_list of scm_cookie and sets it to skb. (We will remove this part after replacing GC.) Here, we add a new function call in unix_attach_fds() to preallocate struct unix_vertex per inflight AF_UNIX fd and link each vertex to skb's scm_fp_list.vertices. When sendmsg() succeeds later, if the socket of the inflight fd is still not inflight yet, we will set the preallocated vertex to struct unix_sock.vertex and link it to a global list unix_unvisited_vertices under spin_lock(&unix_gc_lock). If the socket is already inflight, we free the preallocated vertex. This is to avoid taking the lock unnecessarily when sendmsg() could fail later. In the following patch, we will similarly allocate another struct per edge, which will finally be linked to the inflight socket's unix_vertex.edges. And then, we will count the number of edges as unix_vertex.out_degree. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Acked-by: Paolo Abeni <pabeni@redhat.com> Link: https://lore.kernel.org/r/20240325202425.60930-2-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Lee Jones <lee@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-06-04af_unix: Remove CONFIG_UNIX_SCM.Kuniyuki Iwashima
commit 99a7a5b9943ea2d05fb0dee38e4ae2290477ed83 upstream. Originally, the code related to garbage collection was all in garbage.c. Commit f4e65870e5ce ("net: split out functions related to registering inflight socket files") moved some functions to scm.c for io_uring and added CONFIG_UNIX_SCM just in case AF_UNIX was built as module. However, since commit 97154bcf4d1b ("af_unix: Kconfig: make CONFIG_UNIX bool"), AF_UNIX is no longer built separately. Also, io_uring does not support SCM_RIGHTS now. Let's move the functions back to garbage.c Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Acked-by: Jens Axboe <axboe@kernel.dk> Link: https://lore.kernel.org/r/20240129190435.57228-4-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Lee Jones <lee@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-06-04af_unix: Try to run GC async.Kuniyuki Iwashima
commit d9f21b3613337b55cc9d4a6ead484dca68475143 upstream. If more than 16000 inflight AF_UNIX sockets exist and the garbage collector is not running, unix_(dgram|stream)_sendmsg() call unix_gc(). Also, they wait for unix_gc() to complete. In unix_gc(), all inflight AF_UNIX sockets are traversed at least once, and more if they are the GC candidate. Thus, sendmsg() significantly slows down with too many inflight AF_UNIX sockets. However, if a process sends data with no AF_UNIX FD, the sendmsg() call does not need to wait for GC. After this change, only the process that meets the condition below will be blocked under such a situation. 1) cmsg contains AF_UNIX socket 2) more than 32 AF_UNIX sent by the same user are still inflight Note that even a sendmsg() call that does not meet the condition but has AF_UNIX FD will be blocked later in unix_scm_to_skb() by the spinlock, but we allow that as a bonus for sane users. The results below are the time spent in unix_dgram_sendmsg() sending 1 byte of data with no FD 4096 times on a host where 32K inflight AF_UNIX sockets exist. Without series: the sane sendmsg() needs to wait gc unreasonably. $ sudo /usr/share/bcc/tools/funclatency -p 11165 unix_dgram_sendmsg Tracing 1 functions for "unix_dgram_sendmsg"... Hit Ctrl-C to end. ^C nsecs : count distribution [...] 524288 -> 1048575 : 0 | | 1048576 -> 2097151 : 3881 |****************************************| 2097152 -> 4194303 : 214 |** | 4194304 -> 8388607 : 1 | | avg = 1825567 nsecs, total: 7477526027 nsecs, count: 4096 With series: the sane sendmsg() can finish much faster. $ sudo /usr/share/bcc/tools/funclatency -p 8702 unix_dgram_sendmsg Tracing 1 functions for "unix_dgram_sendmsg"... Hit Ctrl-C to end. ^C nsecs : count distribution [...] 128 -> 255 : 0 | | 256 -> 511 : 4092 |****************************************| 512 -> 1023 : 2 | | 1024 -> 2047 : 0 | | 2048 -> 4095 : 0 | | 4096 -> 8191 : 1 | | 8192 -> 16383 : 1 | | avg = 410 nsecs, total: 1680510 nsecs, count: 4096 Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://lore.kernel.org/r/20240123170856.41348-6-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Lee Jones <lee@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-06-04af_unix: Return struct unix_sock from unix_get_socket().Kuniyuki Iwashima
commit 5b17307bd0789edea0675d524a2b277b93bbde62 upstream. Currently, unix_get_socket() returns struct sock, but after calling it, we always cast it to unix_sk(). Let's return struct unix_sock from unix_get_socket(). Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Acked-by: Pavel Begunkov <asml.silence@gmail.com> Reviewed-by: Simon Horman <horms@kernel.org> Link: https://lore.kernel.org/r/20240123170856.41348-4-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Lee Jones <lee@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-06-04espintcp: remove encap socket caching to avoid reference leakSabrina Dubroca
[ Upstream commit 028363685bd0b7a19b4a820f82dd905b1dc83999 ] The current scheme for caching the encap socket can lead to reference leaks when we try to delete the netns. The reference chain is: xfrm_state -> enacp_sk -> netns Since the encap socket is a userspace socket, it holds a reference on the netns. If we delete the espintcp state (through flush or individual delete) before removing the netns, the reference on the socket is dropped and the netns is correctly deleted. Otherwise, the netns may not be reachable anymore (if all processes within the ns have terminated), so we cannot delete the xfrm state to drop its reference on the socket. This patch results in a small (~2% in my tests) performance regression. A GC-type mechanism could be added for the socket cache, to clear references if the state hasn't been used "recently", but it's a lot more complex than just not caching the socket. Fixes: e27cca96cd68 ("xfrm: add espintcp (RFC 8229)") Signed-off-by: Sabrina Dubroca <sd@queasysnail.net> Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-05-22netfilter: nf_tables: do not defer rule destruction via call_rcuFlorian Westphal
commit b04df3da1b5c6f6dc7cdccc37941740c078c4043 upstream. nf_tables_chain_destroy can sleep, it can't be used from call_rcu callbacks. Moreover, nf_tables_rule_release() is only safe for error unwinding, while transaction mutex is held and the to-be-desroyed rule was not exposed to either dataplane or dumps, as it deactives+frees without the required synchronize_rcu() in-between. nft_rule_expr_deactivate() callbacks will change ->use counters of other chains/sets, see e.g. nft_lookup .deactivate callback, these must be serialized via transaction mutex. Also add a few lockdep asserts to make this more explicit. Calling synchronize_rcu() isn't ideal, but fixing this without is hard and way more intrusive. As-is, we can get: WARNING: .. net/netfilter/nf_tables_api.c:5515 nft_set_destroy+0x.. Workqueue: events nf_tables_trans_destroy_work RIP: 0010:nft_set_destroy+0x3fe/0x5c0 Call Trace: <TASK> nf_tables_trans_destroy_work+0x6b7/0xad0 process_one_work+0x64a/0xce0 worker_thread+0x613/0x10d0 In case the synchronize_rcu becomes an issue, we can explore alternatives. One way would be to allocate nft_trans_rule objects + one nft_trans_chain object, deactivate the rules + the chain and then defer the freeing to the nft destroy workqueue. We'd still need to keep the synchronize_rcu path as a fallback to handle -ENOMEM corner cases though. Reported-by: syzbot+b26935466701e56cfdc2@syzkaller.appspotmail.com Closes: https://lore.kernel.org/all/67478d92.050a0220.253251.0062.GAE@google.com/T/ Fixes: c03d278fdf35 ("netfilter: nf_tables: wait for rcu grace period on net_device removal") Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-05-22netfilter: nf_tables: wait for rcu grace period on net_device removalPablo Neira Ayuso
commit c03d278fdf35e73dd0ec543b9b556876b9d9a8dc upstream. 8c873e219970 ("netfilter: core: free hooks with call_rcu") removed synchronize_net() call when unregistering basechain hook, however, net_device removal event handler for the NFPROTO_NETDEV was not updated to wait for RCU grace period. Note that 835b803377f5 ("netfilter: nf_tables_netdev: unregister hooks on net_device removal") does not remove basechain rules on device removal, I was hinted to remove rules on net_device removal later, see 5ebe0b0eec9d ("netfilter: nf_tables: destroy basechain and rules on netdevice removal"). Although NETDEV_UNREGISTER event is guaranteed to be handled after synchronize_net() call, this path needs to wait for rcu grace period via rcu callback to release basechain hooks if netns is alive because an ongoing netlink dump could be in progress (sockets hold a reference on the netns). Note that nf_tables_pre_exit_net() unregisters and releases basechain hooks but it is possible to see NETDEV_UNREGISTER at a later stage in the netns exit path, eg. veth peer device in another netns: cleanup_net() default_device_exit_batch() unregister_netdevice_many_notify() notifier_call_chain() nf_tables_netdev_event() __nft_release_basechain() In this particular case, same rule of thumb applies: if netns is alive, then wait for rcu grace period because netlink dump in the other netns could be in progress. Otherwise, if the other netns is going away then no netlink dump can be in progress and basechain hooks can be released inmediately. While at it, turn WARN_ON() into WARN_ON_ONCE() for the basechain validation, which should not ever happen. Fixes: 835b803377f5 ("netfilter: nf_tables_netdev: unregister hooks on net_device removal") Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-05-22netfilter: nf_tables: pass nft_chain to destroy function, not nft_ctxFlorian Westphal
commit 8965d42bcf54d42cbc72fe34a9d0ec3f8527debd upstream. It would be better to not store nft_ctx inside nft_trans object, the netlink ctx strucutre is huge and most of its information is never needed in places that use trans->ctx. Avoid/reduce its usage if possible, no runtime behaviour change intended. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Stable-dep-of: c03d278fdf35 ("netfilter: nf_tables: wait for rcu grace period on net_device removal") Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-05-22net_sched: Flush gso_skb list too during ->change()Cong Wang
[ Upstream commit 2d3cbfd6d54a2c39ce3244f33f85c595844bd7b8 ] Previously, when reducing a qdisc's limit via the ->change() operation, only the main skb queue was trimmed, potentially leaving packets in the gso_skb list. This could result in NULL pointer dereference when we only check sch->limit against sch->q.qlen. This patch introduces a new helper, qdisc_dequeue_internal(), which ensures both the gso_skb list and the main queue are properly flushed when trimming excess packets. All relevant qdiscs (codel, fq, fq_codel, fq_pie, hhf, pie) are updated to use this helper in their ->change() routines. Fixes: 76e3cc126bb2 ("codel: Controlled Delay AQM") Fixes: 4b549a2ef4be ("fq_codel: Fair Queue Codel AQM") Fixes: afe4fd062416 ("pkt_sched: fq: Fair Queue packet scheduler") Fixes: ec97ecf1ebe4 ("net: sched: add Flow Queue PIE packet scheduler") Fixes: 10239edf86f1 ("net-qdisc-hhf: Heavy-Hitter Filter (HHF) qdisc") Fixes: d4b36210c2e6 ("net: pkt_sched: PIE AQM scheme") Reported-by: Will <willsroot@protonmail.com> Reported-by: Savy <savy@syst3mfailure.io> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-05-18ipv4: Drop tos parameter from flowi4_update_output()Guillaume Nault
[ Upstream commit 3f06760c00f56c5fe6c7f3361c2cf64becee1174 ] Callers of flowi4_update_output() never try to update ->flowi4_tos: * ip_route_connect() updates ->flowi4_tos with its own current value. * ip_route_newports() has two users: tcp_v4_connect() and dccp_v4_connect. Both initialise fl4 with ip_route_connect(), which in turn sets ->flowi4_tos with RT_TOS(inet_sk(sk)->tos) and ->flowi4_scope based on SOCK_LOCALROUTE. Then ip_route_newports() updates ->flowi4_tos with RT_CONN_FLAGS(sk), which is the same as RT_TOS(inet_sk(sk)->tos), unless SOCK_LOCALROUTE is set on the socket. In that case, the lowest order bit is set to 1, to eventually inform ip_route_output_key_hash() to restrict the scope to RT_SCOPE_LINK. This is equivalent to properly setting ->flowi4_scope as ip_route_connect() did. * ip_vs_xmit.c initialises ->flowi4_tos with memset(0), then calls flowi4_update_output() with tos=0. * sctp_v4_get_dst() uses the same RT_CONN_FLAGS_TOS() when initialising ->flowi4_tos and when calling flowi4_update_output(). In the end, ->flowi4_tos never changes. So let's just drop the tos parameter. This will simplify the conversion of ->flowi4_tos from __u8 to dscp_t. Signed-off-by: Guillaume Nault <gnault@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Stable-dep-of: e34090d7214e ("ipvs: fix uninit-value for saddr in do_output_route4") Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-05-02wifi: mac80211: export ieee80211_purge_tx_queue() for driversPing-Ke Shih
commit 53bc1b73b67836ac9867f93dee7a443986b4a94f upstream. Drivers need to purge TX SKB when stopping. Using skb_queue_purge() can't report TX status to mac80211, causing ieee80211_free_ack_frame() warns "Have pending ack frames!". Export ieee80211_purge_tx_queue() for drivers to not have to reimplement it. Signed-off-by: Ping-Ke Shih <pkshih@realtek.com> Link: https://patch.msgid.link/20240822014255.10211-1-pkshih@realtek.com Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-05-02net: dsa: add support for mac_prepare() and mac_finish() callsRussell King (Oracle)
[ Upstream commit dd805cf3e80e038aeb06902399ce9bd6fafb4ff3 ] Add DSA support for the phylink mac_prepare() and mac_finish() calls. These were introduced as part of the PCS support to allow MACs to perform preparatory steps prior to configuration, and finalisation steps after the MAC and PCS has been configured. Introducing phylink_pcs support to the mv88e6xxx DSA driver needs some code moved out of its mac_config() stage into the mac_prepare() and mac_finish() stages, and this commit facilitates such code in DSA drivers. Reviewed-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> Reviewed-by: Simon Horman <simon.horman@corigine.com> Signed-off-by: David S. Miller <davem@davemloft.net> Stable-dep-of: 52fdc41c3278 ("net: dsa: mv88e6xxx: fix internal PHYs for 6320 family") Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-04-25sctp: detect and prevent references to a freed transport in sendmsgRicardo Cañuelo Navarro
commit f1a69a940de58b16e8249dff26f74c8cc59b32be upstream. sctp_sendmsg() re-uses associations and transports when possible by doing a lookup based on the socket endpoint and the message destination address, and then sctp_sendmsg_to_asoc() sets the selected transport in all the message chunks to be sent. There's a possible race condition if another thread triggers the removal of that selected transport, for instance, by explicitly unbinding an address with setsockopt(SCTP_SOCKOPT_BINDX_REM), after the chunks have been set up and before the message is sent. This can happen if the send buffer is full, during the period when the sender thread temporarily releases the socket lock in sctp_wait_for_sndbuf(). This causes the access to the transport data in sctp_outq_select_transport(), when the association outqueue is flushed, to result in a use-after-free read. This change avoids this scenario by having sctp_transport_free() signal the freeing of the transport, tagging it as "dead". In order to do this, the patch restores the "dead" bit in struct sctp_transport, which was removed in commit 47faa1e4c50e ("sctp: remove the dead field of sctp_transport"). Then, in the scenario where the sender thread has released the socket lock in sctp_wait_for_sndbuf(), the bit is checked again after re-acquiring the socket lock to detect the deletion. This is done while holding a reference to the transport to prevent it from being freed in the process. If the transport was deleted while the socket lock was relinquished, sctp_sendmsg_to_asoc() will return -EAGAIN to let userspace retry the send. The bug was found by a private syzbot instance (see the error report [1] and the C reproducer that triggers it [2]). Link: https://people.igalia.com/rcn/kernel_logs/20250402__KASAN_slab-use-after-free_Read_in_sctp_outq_select_transport.txt [1] Link: https://people.igalia.com/rcn/kernel_logs/20250402__KASAN_slab-use-after-free_Read_in_sctp_outq_select_transport__repro.c [2] Cc: stable@vger.kernel.org Fixes: df132eff4638 ("sctp: clear the transport of some out_chunk_list chunks in sctp_assoc_rm_peer") Suggested-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: Ricardo Cañuelo Navarro <rcn@igalia.com> Acked-by: Xin Long <lucien.xin@gmail.com> Link: https://patch.msgid.link/20250404-kasan_slab-use-after-free_read_in_sctp_outq_select_transport__20250404-v1-1-5ce4a0b78ef2@igalia.com Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-28Revert "Bluetooth: hci_core: Fix sleeping function called from invalid context"Luiz Augusto von Dentz
[ Upstream commit ab6ab707a4d060a51c45fc13e3b2228d5f7c0b87 ] This reverts commit 4d94f05558271654670d18c26c912da0c1c15549 which has problems (see [1]) and is no longer needed since 581dd2dc168f ("Bluetooth: hci_event: Fix using rcu_read_(un)lock while iterating") has reworked the code where the original bug has been found. [1] Link: https://lore.kernel.org/linux-bluetooth/877c55ci1r.wl-tiwai@suse.de/T/#t Fixes: 4d94f0555827 ("Bluetooth: hci_core: Fix sleeping function called from invalid context") Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-03-07include: net: add static inline dst_dev_overhead() to dst.hJustin Iurman
[ Upstream commit 0600cf40e9b36fe17f9c9f04d4f9cef249eaa5e7 ] Add static inline dst_dev_overhead() function to include/net/dst.h. This helper function is used by ioam6_iptunnel, rpl_iptunnel and seg6_iptunnel to get the dev's overhead based on a cache entry (dst_entry). If the cache is empty, the default and generic value skb->mac_len is returned. Otherwise, LL_RESERVED_SPACE() over dst's dev is returned. Signed-off-by: Justin Iurman <justin.iurman@uliege.be> Cc: Alexander Lobakin <aleksander.lobakin@intel.com> Cc: Vadim Fedorenko <vadim.fedorenko@linux.dev> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Stable-dep-of: c64a0727f9b1 ("net: ipv6: fix dst ref loop on input in seg6 lwt") Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-03-07ipv4: Convert ip_route_input() to dscp_t.Guillaume Nault
[ Upstream commit 7e863e5db6185b1add0df4cb01b31a4ed1c4b738 ] Pass a dscp_t variable to ip_route_input(), instead of a plain u8, to prevent accidental setting of ECN bits in ->flowi4_tos. Callers of ip_route_input() to consider are: * input_action_end_dx4_finish() and input_action_end_dt4() in net/ipv6/seg6_local.c. These functions set the tos parameter to 0, which is already a valid dscp_t value, so they don't need to be adjusted for the new prototype. * icmp_route_lookup(), which already has a dscp_t variable to pass as parameter. We just need to remove the inet_dscp_to_dsfield() conversion. * br_nf_pre_routing_finish(), ip_options_rcv_srr() and ip4ip6_err(), which get the DSCP directly from IPv4 headers. Define a helper to read the .tos field of struct iphdr as dscp_t, so that these function don't have to do the conversion manually. While there, declare *iph as const in br_nf_pre_routing_finish(), declare its local variables in reverse-christmas-tree order and move the "err = ip_route_input()" assignment out of the conditional to avoid checkpatch warning. Signed-off-by: Guillaume Nault <gnault@redhat.com> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://patch.msgid.link/e9d40781d64d3d69f4c79ac8a008b8d67a033e8d.1727807926.git.gnault@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Stable-dep-of: 27843ce6ba3d ("ipvlan: ensure network headers are in skb linear part") Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-03-07netfilter: allow exp not to be removed in nf_ct_find_expectationXin Long
commit 4914109a8e1e494c6aa9852f9e84ec77a5fc643f upstream. Currently nf_conntrack_in() calling nf_ct_find_expectation() will remove the exp from the hash table. However, in some scenario, we expect the exp not to be removed when the created ct will not be confirmed, like in OVS and TC conntrack in the following patches. This patch allows exp not to be removed by setting IPS_CONFIRMED in the status of the tmpl. Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Aaron Conole <aconole@redhat.com> Acked-by: Florian Westphal <fw@strlen.de> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-07bpf: Fix wrong copied_seq calculationJiayuan Chen
[ Upstream commit 36b62df5683c315ba58c950f1a9c771c796c30ec ] 'sk->copied_seq' was updated in the tcp_eat_skb() function when the action of a BPF program was SK_REDIRECT. For other actions, like SK_PASS, the update logic for 'sk->copied_seq' was moved to tcp_bpf_recvmsg_parser() to ensure the accuracy of the 'fionread' feature. It works for a single stream_verdict scenario, as it also modified sk_data_ready->sk_psock_verdict_data_ready->tcp_read_skb to remove updating 'sk->copied_seq'. However, for programs where both stream_parser and stream_verdict are active (strparser purpose), tcp_read_sock() was used instead of tcp_read_skb() (sk_data_ready->strp_data_ready->tcp_read_sock). tcp_read_sock() now still updates 'sk->copied_seq', leading to duplicate updates. In summary, for strparser + SK_PASS, copied_seq is redundantly calculated in both tcp_read_sock() and tcp_bpf_recvmsg_parser(). The issue causes incorrect copied_seq calculations, which prevent correct data reads from the recv() interface in user-land. We do not want to add new proto_ops to implement a new version of tcp_read_sock, as this would introduce code complexity [1]. We could have added noack and copied_seq to desc, and then called ops->read_sock. However, unfortunately, other modules didn’t fully initialize desc to zero. So, for now, we are directly calling tcp_read_sock_noack() in tcp_bpf.c. [1]: https://lore.kernel.org/bpf/20241218053408.437295-1-mrpre@163.com Fixes: e5c6de5fa025 ("bpf, sockmap: Incorrectly handling copied_seq") Suggested-by: Jakub Sitnicki <jakub@cloudflare.com> Signed-off-by: Jiayuan Chen <mrpre@163.com> Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://patch.msgid.link/20250122100917.49845-3-mrpre@163.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-03-07strparser: Add read_sock callbackJiayuan Chen
[ Upstream commit 0532a79efd68a4d9686b0385e4993af4b130ff82 ] Added a new read_sock handler, allowing users to customize read operations instead of relying on the native socket's read_sock. Signed-off-by: Jiayuan Chen <mrpre@163.com> Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://patch.msgid.link/20250122100917.49845-2-mrpre@163.com Stable-dep-of: 36b62df5683c ("bpf: Fix wrong copied_seq calculation") Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-03-07tcp: drop secpath at the same time as we currently drop dstSabrina Dubroca
[ Upstream commit 9b6412e6979f6f9e0632075f8f008937b5cd4efd ] Xiumei reported hitting the WARN in xfrm6_tunnel_net_exit while running tests that boil down to: - create a pair of netns - run a basic TCP test over ipcomp6 - delete the pair of netns The xfrm_state found on spi_byaddr was not deleted at the time we delete the netns, because we still have a reference on it. This lingering reference comes from a secpath (which holds a ref on the xfrm_state), which is still attached to an skb. This skb is not leaked, it ends up on sk_receive_queue and then gets defer-free'd by skb_attempt_defer_free. The problem happens when we defer freeing an skb (push it on one CPU's defer_list), and don't flush that list before the netns is deleted. In that case, we still have a reference on the xfrm_state that we don't expect at this point. We already drop the skb's dst in the TCP receive path when it's no longer needed, so let's also drop the secpath. At this point, tcp_filter has already called into the LSM hooks that may require the secpath, so it should not be needed anymore. However, in some of those places, the MPTCP extension has just been attached to the skb, so we cannot simply drop all extensions. Fixes: 68822bdf76f1 ("net: generalize skb freeing deferral to per-cpu lists") Reported-by: Xiumei Mu <xmu@redhat.com> Signed-off-by: Sabrina Dubroca <sd@queasysnail.net> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/5055ba8f8f72bdcb602faa299faca73c280b7735.1739743613.git.sd@queasysnail.net Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-02-21net: add dev_net_rcu() helperEric Dumazet
[ Upstream commit 482ad2a4ace2740ca0ff1cbc8f3c7f862f3ab507 ] dev->nd_net can change, readers should either use rcu_read_lock() or RTNL. We currently use a generic helper, dev_net() with no debugging support. We probably have many hidden bugs. Add dev_net_rcu() helper for callers using rcu_read_lock() protection. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20250205155120.1676781-2-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Stable-dep-of: 71b8471c93fa ("ipv4: use RCU protection in ipv4_default_advmss()") Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-02-21net: treat possible_net_t net pointer as an RCU one and add read_pnet_rcu()Jiri Pirko
[ Upstream commit 2034d90ae41ae93e30d492ebcf1f06f97a9cfba6 ] Make the net pointer stored in possible_net_t structure annotated as an RCU pointer. Change the access helpers to treat it as such. Introduce read_pnet_rcu() helper to allow caller to dereference the net pointer under RCU read lock. Signed-off-by: Jiri Pirko <jiri@nvidia.com> Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net> Stable-dep-of: 71b8471c93fa ("ipv4: use RCU protection in ipv4_default_advmss()") Signed-off-by: Sasha Levin <sashal@kernel.org>