user/sven/linux.git/include, branch v6.12.55

mm/ksm: fix flag-dropping behavior in ksm_madvise

2025-10-23T14:20:47Z

commit f04aad36a07cc17b7a5d5b9a2d386ce6fae63e93 upstream. syzkaller discovered the following crash: (kernel BUG) [ 44.607039] ------------[ cut here ]------------ [ 44.607422] kernel BUG at mm/userfaultfd.c:2067! [ 44.608148] Oops: invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN NOPTI [ 44.608814] CPU: 1 UID: 0 PID: 2475 Comm: reproducer Not tainted 6.16.0-rc6 #1 PREEMPT(none) [ 44.609635] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014 [ 44.610695] RIP: 0010:userfaultfd_release_all+0x3a8/0x460 [ 44.617726] Call Trace: [ 44.617926] [ 44.619284] userfaultfd_release+0xef/0x1b0 [ 44.620976] __fput+0x3f9/0xb60 [ 44.621240] fput_close_sync+0x110/0x210 [ 44.622222] __x64_sys_close+0x8f/0x120 [ 44.622530] do_syscall_64+0x5b/0x2f0 [ 44.622840] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 44.623244] RIP: 0033:0x7f365bb3f227 Kernel panics because it detects UFFD inconsistency during userfaultfd_release_all(). Specifically, a VMA which has a valid pointer to vma->vm_userfaultfd_ctx, but no UFFD flags in vma->vm_flags. The inconsistency is caused in ksm_madvise(): when user calls madvise() with MADV_UNMEARGEABLE on a VMA that is registered for UFFD in MINOR mode, it accidentally clears all flags stored in the upper 32 bits of vma->vm_flags. Assuming x86_64 kernel build, unsigned long is 64-bit and unsigned int and int are 32-bit wide. This setup causes the following mishap during the &= ~VM_MERGEABLE assignment. VM_MERGEABLE is a 32-bit constant of type unsigned int, 0x8000'0000. After ~ is applied, it becomes 0x7fff'ffff unsigned int, which is then promoted to unsigned long before the & operation. This promotion fills upper 32 bits with leading 0s, as we're doing unsigned conversion (and even for a signed conversion, this wouldn't help as the leading bit is 0). & operation thus ends up AND-ing vm_flags with 0x0000'0000'7fff'ffff instead of intended 0xffff'ffff'7fff'ffff and hence accidentally clears the upper 32-bits of its value. Fix it by changing `VM_MERGEABLE` constant to unsigned long, using the BIT() macro. Note: other VM_* flags are not affected: This only happens to the VM_MERGEABLE flag, as the other VM_* flags are all constants of type int and after ~ operation, they end up with leading 1 and are thus converted to unsigned long with leading 1s. Note 2: After commit 31defc3b01d9 ("userfaultfd: remove (VM_)BUG_ON()s"), this is no longer a kernel BUG, but a WARNING at the same place: [ 45.595973] WARNING: CPU: 1 PID: 2474 at mm/userfaultfd.c:2067 but the root-cause (flag-drop) remains the same. [akpm@linux-foundation.org: rust bindgen wasn't able to handle BIT(), from Miguel] Link: https://lore.kernel.org/oe-kbuild-all/202510030449.VfSaAjvd-lkp@intel.com/ Link: https://lkml.kernel.org/r/20251001090353.57523-2-acsjakub@amazon.de Fixes: 7677f7fd8be7 ("userfaultfd: add minor fault registration mode") Signed-off-by: Jakub Acs Signed-off-by: Miguel Ojeda Acked-by: David Hildenbrand Acked-by: SeongJae Park Tested-by: Alice Ryhl Tested-by: Miguel Ojeda Cc: Xu Xin Cc: Chengming Zhou Cc: Peter Xu Cc: Axel Rasmussen Cc: Signed-off-by: Andrew Morton [acsjakub@amazon.de: adjust context in bindgings_helper.h] Signed-off-by: Jakub Acs Signed-off-by: Greg Kroah-Hartman

net: Add locking to protect skb->dev access in ip_output

2025-10-23T14:20:45Z

[ Upstream commit 1dbf1d590d10a6d1978e8184f8dfe20af22d680a ] In ip_output() skb->dev is updated from the skb_dst(skb)->dev this can become invalid when the interface is unregistered and freed, Introduced new skb_dst_dev_rcu() function to be used instead of skb_dst_dev() within rcu_locks in ip_output.This will ensure that all the skb's associated with the dev being deregistered will be transnmitted out first, before freeing the dev. Given that ip_output() is called within an rcu_read_lock() critical section or from a bottom-half context, it is safe to introduce an RCU read-side critical section within it. Multiple panic call stacks were observed when UL traffic was run in concurrency with device deregistration from different functions, pasting one sample for reference. [496733.627565][T13385] Call trace: [496733.627570][T13385] bpf_prog_ce7c9180c3b128ea_cgroupskb_egres+0x24c/0x7f0 [496733.627581][T13385] __cgroup_bpf_run_filter_skb+0x128/0x498 [496733.627595][T13385] ip_finish_output+0xa4/0xf4 [496733.627605][T13385] ip_output+0x100/0x1a0 [496733.627613][T13385] ip_send_skb+0x68/0x100 [496733.627618][T13385] udp_send_skb+0x1c4/0x384 [496733.627625][T13385] udp_sendmsg+0x7b0/0x898 [496733.627631][T13385] inet_sendmsg+0x5c/0x7c [496733.627639][T13385] __sys_sendto+0x174/0x1e4 [496733.627647][T13385] __arm64_sys_sendto+0x28/0x3c [496733.627653][T13385] invoke_syscall+0x58/0x11c [496733.627662][T13385] el0_svc_common+0x88/0xf4 [496733.627669][T13385] do_el0_svc+0x2c/0xb0 [496733.627676][T13385] el0_svc+0x2c/0xa4 [496733.627683][T13385] el0t_64_sync_handler+0x68/0xb4 [496733.627689][T13385] el0t_64_sync+0x1a4/0x1a8 Changes in v3: - Replaced WARN_ON() with WARN_ON_ONCE(), as suggested by Willem de Bruijn. - Dropped legacy lines mistakenly pulled in from an outdated branch. Changes in v2: - Addressed review comments from Eric Dumazet - Used READ_ONCE() to prevent potential load/store tearing - Added skb_dst_dev_rcu() and used along with rcu_read_lock() in ip_output Signed-off-by: Sharath Chandra Vurukala Reviewed-by: Eric Dumazet Link: https://patch.msgid.link/20250730105118.GA26100@hu-sharathv-hyd.qualcomm.com Signed-off-by: Jakub Kicinski Stable-dep-of: 833d4313bc1e ("mptcp: reset blackhole on success with non-loopback ifaces") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

ipv4: adopt dst_dev, skb_dst_dev and skb_dst_dev_net[_rcu]

2025-10-23T14:20:45Z

[ Upstream commit a74fc62eec155ca5a6da8ff3856f3dc87fe24558 ] Use the new helpers as a first step to deal with potential dst->dev races. Signed-off-by: Eric Dumazet Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20250630121934.3399505-8-edumazet@google.com Signed-off-by: Jakub Kicinski Stable-dep-of: 833d4313bc1e ("mptcp: reset blackhole on success with non-loopback ifaces") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

net: dst: add four helpers to annotate data-races around dst->dev

2025-10-23T14:20:45Z

[ Upstream commit 88fe14253e181878c2ddb51a298ae8c468a63010 ] dst->dev is read locklessly in many contexts, and written in dst_dev_put(). Fixing all the races is going to need many changes. We probably will have to add full RCU protection. Add three helpers to ease this painful process. static inline struct net_device *dst_dev(const struct dst_entry *dst) { return READ_ONCE(dst->dev); } static inline struct net_device *skb_dst_dev(const struct sk_buff *skb) { return dst_dev(skb_dst(skb)); } static inline struct net *skb_dst_dev_net(const struct sk_buff *skb) { return dev_net(skb_dst_dev(skb)); } static inline struct net *skb_dst_dev_net_rcu(const struct sk_buff *skb) { return dev_net_rcu(skb_dst_dev(skb)); } Fixes: 4a6ce2b6f2ec ("net: introduce a new function dst_dev_put()") Signed-off-by: Eric Dumazet Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20250630121934.3399505-7-edumazet@google.com Signed-off-by: Jakub Kicinski Stable-dep-of: 833d4313bc1e ("mptcp: reset blackhole on success with non-loopback ifaces") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

tcp: cache RTAX_QUICKACK metric in a hot cache line

2025-10-23T14:20:45Z

[ Upstream commit 15492700ac41459b54a6683490adcee350ab11e3 ] tcp_in_quickack_mode() is called from input path for small packets. It calls __sk_dst_get() which reads sk->sk_dst_cache which has been put in sock_read_tx group (for good reasons). Then dst_metric(dst, RTAX_QUICKACK) also needs extra cache line misses. Cache RTAX_QUICKACK in icsk->icsk_ack.dst_quick_ack to no longer pull these cache lines for the cases a delayed ACK is scheduled. After this patch TCP receive path does not longer access sock_read_tx group. Signed-off-by: Eric Dumazet Reviewed-by: Jason Xing Reviewed-by: Neal Cardwell Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20250312083907.1931644-1-edumazet@google.com Signed-off-by: Paolo Abeni Stable-dep-of: 833d4313bc1e ("mptcp: reset blackhole on success with non-loopback ifaces") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

tcp: convert to dev_net_rcu()

2025-10-23T14:20:44Z

[ Upstream commit e7b9ecce562ca6a1de32c56c597fa45e08c44ec0 ] TCP uses of dev_net() are under RCU protection, change them to dev_net_rcu() to get LOCKDEP support. Signed-off-by: Eric Dumazet Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20250301201424.2046477-4-edumazet@google.com Signed-off-by: Jakub Kicinski Stable-dep-of: 833d4313bc1e ("mptcp: reset blackhole on success with non-loopback ifaces") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

PCI: Add PCI_VDEVICE_SUB helper macro

2025-10-23T14:20:44Z

[ Upstream commit 208fff3f567e2a3c3e7e4788845e90245c3891b4 ] PCI_VDEVICE_SUB generates the pci_device_id struct layout for the specific PCI device/subdevice. Private data may follow the output. Reviewed-by: Przemek Kitszel Signed-off-by: Piotr Kwapulinski Acked-by: Bjorn Helgaas Tested-by: Rafal Romanowski Signed-off-by: Tony Nguyen Stable-dep-of: a7075f501bd3 ("ixgbevf: fix mailbox API compatibility by negotiating supported features") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

PM: runtime: Add new devm functions

2025-10-23T14:20:39Z

[ Upstream commit 73db799bf5efc5a04654bb3ff6c9bf63a0dfa473 ] Add `devm_pm_runtime_set_active_enabled()` and `devm_pm_runtime_get_noresume()` for simplifying common cases in drivers. Signed-off-by: Bence Csókás Link: https://patch.msgid.link/20250327195928.680771-3-csokas.bence@prolan.hu Signed-off-by: Rafael J. Wysocki Stable-dep-of: 0792c1984a45 ("iio: imu: inv_icm42600: Simplify pm_runtime setup") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

net/ip6_tunnel: Prevent perpetual tunnel growth

2025-10-23T14:20:29Z

[ Upstream commit 21f4d45eba0b2dcae5dbc9e5e0ad08735c993f16 ] Similarly to ipv4 tunnel, ipv6 version updates dev->needed_headroom, too. While ipv4 tunnel headroom adjustment growth was limited in commit 5ae1e9922bbd ("net: ip_tunnel: prevent perpetual headroom growth"), ipv6 tunnel yet increases the headroom without any ceiling. Reflect ipv4 tunnel headroom adjustment limit on ipv6 version. Credits to Francesco Ruggeri, who was originally debugging this issue and wrote local Arista-specific patch and a reproducer. Fixes: 8eb30be0352d ("ipv6: Create ip6_tnl_xmit") Cc: Florian Westphal Cc: Francesco Ruggeri Signed-off-by: Dmitry Safonov Link: https://patch.msgid.link/20251009-ip6_tunnel-headroom-v2-1-8e4dbd8f7e35@arista.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

usb: gadget: Introduce free_usb_request helper

2025-10-23T14:20:25Z

[ Upstream commit 201c53c687f2b55a7cc6d9f4000af4797860174b ] Introduce the free_usb_request() function that frees both the request's buffer and the request itself. This function serves as the cleanup callback for DEFINE_FREE() to enable automatic, scope-based cleanup for usb_request pointers. Signed-off-by: Kuen-Han Tsai Link: https://lore.kernel.org/r/20250916-ready-v1-2-4997bf277548@google.com Signed-off-by: Greg Kroah-Hartman Link: https://lore.kernel.org/r/20250916-ready-v1-2-4997bf277548@google.com Stable-dep-of: 75a5b8d4ddd4 ("usb: gadget: f_ncm: Refactor bind path to use __free()") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman