user/sven/linux.git/net, branch v4.14.334

appletalk: Fix Use-After-Free in atalk_ioctl

2023-12-20T14:32:34Z

[ Upstream commit 189ff16722ee36ced4d2a2469d4ab65a8fee4198 ] Because atalk_ioctl() accesses sk->sk_receive_queue without holding a sk->sk_receive_queue.lock, it can cause a race with atalk_recvmsg(). A use-after-free for skb occurs with the following flow. ``` atalk_ioctl() -> skb_peek() atalk_recvmsg() -> skb_recv_datagram() -> skb_free_datagram() ``` Add sk->sk_receive_queue.lock to atalk_ioctl() to fix this issue. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Hyunwoo Kim Link: https://lore.kernel.org/r/20231213041056.GA519680@v4bel-B760M-AORUS-ELITE-AX Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

vsock/virtio: Fix unsigned integer wrap around in virtio_transport_has_space()

2023-12-20T14:32:34Z

[ Upstream commit 60316d7f10b17a7ebb1ead0642fee8710e1560e0 ] We need to do signed arithmetic if we expect condition `if (bytes < 0)` to be possible Found by Linux Verification Center (linuxtesting.org) with SVACE Fixes: 06a8fc78367d ("VSOCK: Introduce virtio_vsock_common.ko") Signed-off-by: Nikolay Kuratov Reviewed-by: Stefano Garzarella Link: https://lore.kernel.org/r/20231211162317.4116625-1-kniv@yandex-team.ru Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

net: Remove acked SYN flag from packet in the transmit queue correctly

2023-12-20T14:32:33Z

[ Upstream commit f99cd56230f56c8b6b33713c5be4da5d6766be1f ] syzkaller report: kernel BUG at net/core/skbuff.c:3452! invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI CPU: 0 PID: 0 Comm: swapper/0 Not tainted 6.7.0-rc4-00009-gbee0e7762ad2-dirty #135 RIP: 0010:skb_copy_and_csum_bits (net/core/skbuff.c:3452) Call Trace: icmp_glue_bits (net/ipv4/icmp.c:357) __ip_append_data.isra.0 (net/ipv4/ip_output.c:1165) ip_append_data (net/ipv4/ip_output.c:1362 net/ipv4/ip_output.c:1341) icmp_push_reply (net/ipv4/icmp.c:370) __icmp_send (./include/net/route.h:252 net/ipv4/icmp.c:772) ip_fragment.constprop.0 (./include/linux/skbuff.h:1234 net/ipv4/ip_output.c:592 net/ipv4/ip_output.c:577) __ip_finish_output (net/ipv4/ip_output.c:311 net/ipv4/ip_output.c:295) ip_output (net/ipv4/ip_output.c:427) __ip_queue_xmit (net/ipv4/ip_output.c:535) __tcp_transmit_skb (net/ipv4/tcp_output.c:1462) __tcp_retransmit_skb (net/ipv4/tcp_output.c:3387) tcp_retransmit_skb (net/ipv4/tcp_output.c:3404) tcp_retransmit_timer (net/ipv4/tcp_timer.c:604) tcp_write_timer (./include/linux/spinlock.h:391 net/ipv4/tcp_timer.c:716) The panic issue was trigered by tcp simultaneous initiation. The initiation process is as follows: TCP A TCP B 1. CLOSED CLOSED 2. SYN-SENT --> ... 3. SYN-RECEIVED <-- <-- SYN-SENT 4. ... --> SYN-RECEIVED 5. SYN-RECEIVED --> ... // TCP B: not send challenge ack for ack limit or packet loss // TCP A: close tcp_close tcp_send_fin if (!tskb && tcp_under_memory_pressure(sk)) tskb = skb_rb_last(&sk->tcp_rtx_queue); //pick SYN_ACK packet TCP_SKB_CB(tskb)->tcp_flags |= TCPHDR_FIN; // set FIN flag 6. FIN_WAIT_1 --> ... // TCP B: send challenge ack to SYN_FIN_ACK 7. ... <-- SYN-RECEIVED //challenge ack // TCP A: 8. FIN_WAIT_1 --> ... // retransmit panic __tcp_retransmit_skb //skb->len=0 tcp_trim_head len = tp->snd_una - TCP_SKB_CB(skb)->seq // len=101-100 __pskb_trim_head skb->data_len -= len // skb->len=-1, wrap around ... ... ip_fragment icmp_glue_bits //BUG_ON If we use tcp_trim_head() to remove acked SYN from packet that contains data or other flags, skb->len will be incorrectly decremented. We can remove SYN flag that has been acked from rtx_queue earlier than tcp_trim_head(), which can fix the problem mentioned above. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Co-developed-by: Eric Dumazet Signed-off-by: Eric Dumazet Signed-off-by: Dong Chenchen Link: https://lore.kernel.org/r/20231210020200.1539875-1-dongchenchen2@huawei.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

net/rose: Fix Use-After-Free in rose_ioctl

2023-12-20T14:32:33Z

[ Upstream commit 810c38a369a0a0ce625b5c12169abce1dd9ccd53 ] Because rose_ioctl() accesses sk->sk_receive_queue without holding a sk->sk_receive_queue.lock, it can cause a race with rose_accept(). A use-after-free for skb occurs with the following flow. ``` rose_ioctl() -> skb_peek() rose_accept() -> skb_dequeue() -> kfree_skb() ``` Add sk->sk_receive_queue.lock to rose_ioctl() to fix this issue. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Hyunwoo Kim Link: https://lore.kernel.org/r/20231209100538.GA407321@v4bel-B760M-AORUS-ELITE-AX Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

atm: Fix Use-After-Free in do_vcc_ioctl

2023-12-20T14:32:32Z

[ Upstream commit 24e90b9e34f9e039f56b5f25f6e6eb92cdd8f4b3 ] Because do_vcc_ioctl() accesses sk->sk_receive_queue without holding a sk->sk_receive_queue.lock, it can cause a race with vcc_recvmsg(). A use-after-free for skb occurs with the following flow. ``` do_vcc_ioctl() -> skb_peek() vcc_recvmsg() -> skb_recv_datagram() -> skb_free_datagram() ``` Add sk->sk_receive_queue.lock to do_vcc_ioctl() to fix this issue. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Hyunwoo Kim Link: https://lore.kernel.org/r/20231209094210.GA403126@v4bel-B760M-AORUS-ELITE-AX Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

drop_monitor: Require 'CAP_SYS_ADMIN' when joining "events" group

2023-12-13T15:46:18Z

commit e03781879a0d524ce3126678d50a80484a513c4b upstream. The "NET_DM" generic netlink family notifies drop locations over the "events" multicast group. This is problematic since by default generic netlink allows non-root users to listen to these notifications. Fix by adding a new field to the generic netlink multicast group structure that when set prevents non-root users or root without the 'CAP_SYS_ADMIN' capability (in the user namespace owning the network namespace) from joining the group. Set this field for the "events" group. Use 'CAP_SYS_ADMIN' rather than 'CAP_NET_ADMIN' because of the nature of the information that is shared over this group. Note that the capability check in this case will always be performed against the initial user namespace since the family is not netns aware and only operates in the initial network namespace. A new field is added to the structure rather than using the "flags" field because the existing field uses uAPI flags and it is inappropriate to add a new uAPI flag for an internal kernel check. In net-next we can rework the "flags" field to use internal flags and fold the new field into it. But for now, in order to reduce the amount of changes, add a new field. Since the information can only be consumed by root, mark the control plane operations that start and stop the tracing as root-only using the 'GENL_ADMIN_PERM' flag. Tested using [1]. Before: # capsh -- -c ./dm_repo # capsh --drop=cap_sys_admin -- -c ./dm_repo After: # capsh -- -c ./dm_repo # capsh --drop=cap_sys_admin -- -c ./dm_repo Failed to join "events" multicast group [1] $ cat dm.c #include #include #include #include int main(int argc, char **argv) { struct nl_sock *sk; int grp, err; sk = nl_socket_alloc(); if (!sk) { fprintf(stderr, "Failed to allocate socket\n"); return -1; } err = genl_connect(sk); if (err) { fprintf(stderr, "Failed to connect socket\n"); return err; } grp = genl_ctrl_resolve_grp(sk, "NET_DM", "events"); if (grp < 0) { fprintf(stderr, "Failed to resolve \"events\" multicast group\n"); return grp; } err = nl_socket_add_memberships(sk, grp, NFNLGRP_NONE); if (err) { fprintf(stderr, "Failed to join \"events\" multicast group\n"); return err; } return 0; } $ gcc -I/usr/include/libnl3 -lnl-3 -lnl-genl-3 -o dm_repo dm.c Fixes: 9a8afc8d3962 ("Network Drop Monitor: Adding drop monitor implementation & Netlink protocol") Reported-by: "The UK's National Cyber Security Centre (NCSC)" Signed-off-by: Ido Schimmel Reviewed-by: Jacob Keller Reviewed-by: Jiri Pirko Link: https://lore.kernel.org/r/20231206213102.1824398-3-idosch@nvidia.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

psample: Require 'CAP_NET_ADMIN' when joining "packets" group

2023-12-13T15:46:17Z

commit 44ec98ea5ea9cfecd31a5c4cc124703cb5442832 upstream. The "psample" generic netlink family notifies sampled packets over the "packets" multicast group. This is problematic since by default generic netlink allows non-root users to listen to these notifications. Fix by marking the group with the 'GENL_UNS_ADMIN_PERM' flag. This will prevent non-root users or root without the 'CAP_NET_ADMIN' capability (in the user namespace owning the network namespace) from joining the group. Tested using [1]. Before: # capsh -- -c ./psample_repo # capsh --drop=cap_net_admin -- -c ./psample_repo After: # capsh -- -c ./psample_repo # capsh --drop=cap_net_admin -- -c ./psample_repo Failed to join "packets" multicast group [1] $ cat psample.c #include #include #include #include int join_grp(struct nl_sock *sk, const char *grp_name) { int grp, err; grp = genl_ctrl_resolve_grp(sk, "psample", grp_name); if (grp < 0) { fprintf(stderr, "Failed to resolve \"%s\" multicast group\n", grp_name); return grp; } err = nl_socket_add_memberships(sk, grp, NFNLGRP_NONE); if (err) { fprintf(stderr, "Failed to join \"%s\" multicast group\n", grp_name); return err; } return 0; } int main(int argc, char **argv) { struct nl_sock *sk; int err; sk = nl_socket_alloc(); if (!sk) { fprintf(stderr, "Failed to allocate socket\n"); return -1; } err = genl_connect(sk); if (err) { fprintf(stderr, "Failed to connect socket\n"); return err; } err = join_grp(sk, "config"); if (err) return err; err = join_grp(sk, "packets"); if (err) return err; return 0; } $ gcc -I/usr/include/libnl3 -lnl-3 -lnl-genl-3 -o psample_repo psample.c Fixes: 6ae0a6286171 ("net: Introduce psample, a new genetlink channel for packet sampling") Reported-by: "The UK's National Cyber Security Centre (NCSC)" Signed-off-by: Ido Schimmel Reviewed-by: Jacob Keller Reviewed-by: Jiri Pirko Link: https://lore.kernel.org/r/20231206213102.1824398-2-idosch@nvidia.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

genetlink: add CAP_NET_ADMIN test for multicast bind

2023-12-13T15:46:17Z

This is a partial backport of upstream commit 4d54cc32112d ("mptcp: avoid lock_fast usage in accept path"). It is only a partial backport because the patch in the link below was erroneously squash-merged into upstream commit 4d54cc32112d ("mptcp: avoid lock_fast usage in accept path"). Below is the original patch description from Florian Westphal: " genetlink sets NL_CFG_F_NONROOT_RECV for its netlink socket so anyone can subscribe to multicast messages. rtnetlink doesn't allow this unconditionally, rtnetlink_bind() restricts bind requests to CAP_NET_ADMIN for a few groups. This allows to set GENL_UNS_ADMIN_PERM flag on genl mcast groups to mandate CAP_NET_ADMIN. This will be used by the upcoming mptcp netlink event facility which exposes the token (mptcp connection identifier) to userspace. " Link: https://lore.kernel.org/mptcp/20210213000001.379332-8-mathew.j.martineau@linux.intel.com/ Signed-off-by: Ido Schimmel Signed-off-by: Greg Kroah-Hartman

netlink: don't call ->netlink_bind with table lock held

2023-12-13T15:46:17Z

From: Florian Westphal commit f2764bd4f6a8dffaec3e220728385d9756b3c2cb upstream. When I added support to allow generic netlink multicast groups to be restricted to subscribers with CAP_NET_ADMIN I was unaware that a genl_bind implementation already existed in the past. It was reverted due to ABBA deadlock: 1. ->netlink_bind gets called with the table lock held. 2. genetlink bind callback is invoked, it grabs the genl lock. But when a new genl subsystem is (un)registered, these two locks are taken in reverse order. One solution would be to revert again and add a comment in genl referring 1e82a62fec613, "genetlink: remove genl_bind"). This would need a second change in mptcp to not expose the raw token value anymore, e.g. by hashing the token with a secret key so userspace can still associate subflow events with the correct mptcp connection. However, Paolo Abeni reminded me to double-check why the netlink table is locked in the first place. I can't find one. netlink_bind() is already called without this lock when userspace joins a group via NETLINK_ADD_MEMBERSHIP setsockopt. Same holds for the netlink_unbind operation. Digging through the history, commit f773608026ee1 ("netlink: access nlk groups safely in netlink bind and getname") expanded the lock scope. commit 3a20773beeeeade ("net: netlink: cap max groups which will be considered in netlink_bind()") ... removed the nlk->ngroups access that the lock scope extension was all about. Reduce the lock scope again and always call ->netlink_bind without the table lock. The Fixes tag should be vs. the patch mentioned in the link below, but that one got squash-merged into the patch that came earlier in the series. Fixes: 4d54cc32112d8d ("mptcp: avoid lock_fast usage in accept path") Link: https://lore.kernel.org/mptcp/20210213000001.379332-8-mathew.j.martineau@linux.intel.com/T/#u Cc: Cong Wang Cc: Xin Long Cc: Johannes Berg Cc: Sean Tranchetti Cc: Paolo Abeni Cc: Pablo Neira Ayuso Signed-off-by: Florian Westphal Signed-off-by: David S. Miller Signed-off-by: Ido Schimmel Signed-off-by: Greg Kroah-Hartman

packet: Move reference count in packet_sock to atomic_long_t

2023-12-13T15:46:16Z

commit db3fadacaf0c817b222090290d06ca2a338422d0 upstream. In some potential instances the reference count on struct packet_sock could be saturated and cause overflows which gets the kernel a bit confused. To prevent this, move to a 64-bit atomic reference count on 64-bit architectures to prevent the possibility of this type to overflow. Because we can not handle saturation, using refcount_t is not possible in this place. Maybe someday in the future if it changes it could be used. Also, instead of using plain atomic64_t, use atomic_long_t instead. 32-bit machines tend to be memory-limited (i.e. anything that increases a reference uses so much memory that you can't actually get to 2**32 references). 32-bit architectures also tend to have serious problems with 64-bit atomics. Hence, atomic_long_t is the more natural solution. Reported-by: "The UK's National Cyber Security Centre (NCSC)" Co-developed-by: Greg Kroah-Hartman Signed-off-by: Greg Kroah-Hartman Signed-off-by: Daniel Borkmann Cc: Linus Torvalds Cc: stable@kernel.org Reviewed-by: Willem de Bruijn Reviewed-by: Eric Dumazet Link: https://lore.kernel.org/r/20231201131021.19999-1-daniel@iogearbox.net Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman