[syzbot] [net?] KMSAN: uninit-value in pfkey_send_notify

[syzbot <syzbot+2d494ba0c96e096f1c11@syzkaller.appspotmail.com>]

Hello,

syzbot found the following issue on:

HEAD commit:    c30a13538d9f Merge tag 'bpf-fixes' of git://git.kernel.org..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=17bb7ea2580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=9ee158fa735566e2
dashboard link: https://syzkaller.appspot.com/bug?extid=2d494ba0c96e096f1c11
compiler:       Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/d7d8c2a837fb/disk-c30a1353.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/9e67e86fa1fd/vmlinux-c30a1353.xz
kernel image: https://storage.googleapis.com/syzbot-assets/731ca108689d/bzImage-c30a1353.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+2d494ba0c96e096f1c11@syzkaller.appspotmail.com

=====================================================
BUG: KMSAN: uninit-value in arch_atomic_read arch/x86/include/asm/atomic.h:23 [inline]
BUG: KMSAN: uninit-value in raw_atomic_read include/linux/atomic/atomic-arch-fallback.h:457 [inline]
BUG: KMSAN: uninit-value in atomic_read include/linux/atomic/atomic-instrumented.h:33 [inline]
BUG: KMSAN: uninit-value in pfkey_send_notify+0x291/0xe60 net/key/af_key.c:3079
 arch_atomic_read arch/x86/include/asm/atomic.h:23 [inline]
 raw_atomic_read include/linux/atomic/atomic-arch-fallback.h:457 [inline]
 atomic_read include/linux/atomic/atomic-instrumented.h:33 [inline]
 pfkey_send_notify+0x291/0xe60 net/key/af_key.c:3079
 km_state_notify net/xfrm/xfrm_state.c:2738 [inline]
 km_state_expired net/xfrm/xfrm_state.c:2752 [inline]
 xfrm_timer_handler+0x464/0x1320 net/xfrm/xfrm_state.c:718
 __run_hrtimer kernel/time/hrtimer.c:1761 [inline]
 __hrtimer_run_queues+0x556/0xd80 kernel/time/hrtimer.c:1825
 hrtimer_run_softirq+0x18e/0x760 kernel/time/hrtimer.c:1842
 handle_softirqs+0x166/0x6e0 kernel/softirq.c:579
 __do_softirq+0x14/0x1b kernel/softirq.c:613
 do_softirq+0x99/0x100 kernel/softirq.c:480
 __local_bh_enable_ip+0xa1/0xb0 kernel/softirq.c:407
 __raw_spin_unlock_bh include/linux/spinlock_api_smp.h:167 [inline]
 _raw_spin_unlock_bh+0x2d/0x40 kernel/locking/spinlock.c:210
 spin_unlock_bh include/linux/spinlock.h:396 [inline]
 __fib6_clean_all net/ipv6/ip6_fib.c:2317 [inline]
 fib6_clean_all+0x1fa/0x300 net/ipv6/ip6_fib.c:2326
 rt6_sync_up+0x157/0x180 net/ipv6/route.c:4891
 addrconf_notify+0x1cd7/0x1d10 net/ipv6/addrconf.c:3728
 notifier_call_chain kernel/notifier.c:85 [inline]
 raw_notifier_call_chain+0xdd/0x410 kernel/notifier.c:453
 call_netdevice_notifiers_info+0x1ac/0x2b0 net/core/dev.c:2229
 netif_state_change+0x3af/0x410 net/core/dev.c:1583
 do_setlink+0x1b33/0x7e50 net/core/rtnetlink.c:3390
 rtnl_group_changelink net/core/rtnetlink.c:3775 [inline]
 __rtnl_newlink net/core/rtnetlink.c:3929 [inline]
 rtnl_newlink+0x2b96/0x3a90 net/core/rtnetlink.c:4057
 rtnetlink_rcv_msg+0x106f/0x14b0 net/core/rtnetlink.c:6946
 netlink_rcv_skb+0x54d/0x680 net/netlink/af_netlink.c:2552
 rtnetlink_rcv+0x35/0x40 net/core/rtnetlink.c:6973
 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
 netlink_unicast+0xf04/0x12b0 net/netlink/af_netlink.c:1346
 netlink_sendmsg+0x10b3/0x1250 net/netlink/af_netlink.c:1896
 sock_sendmsg_nosec net/socket.c:714 [inline]
 __sock_sendmsg+0x330/0x3d0 net/socket.c:729
 ____sys_sendmsg+0x7e0/0xd80 net/socket.c:2614
 ___sys_sendmsg+0x271/0x3b0 net/socket.c:2668
 __sys_sendmsg net/socket.c:2700 [inline]
 __do_sys_sendmsg net/socket.c:2705 [inline]
 __se_sys_sendmsg net/socket.c:2703 [inline]
 __x64_sys_sendmsg+0x211/0x3e0 net/socket.c:2703
 x64_sys_call+0x1dfd/0x3e20 arch/x86/include/generated/asm/syscalls_64.h:47
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd9/0x210 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Uninit was created at:
 slab_post_alloc_hook mm/slub.c:4186 [inline]
 slab_alloc_node mm/slub.c:4229 [inline]
 __do_kmalloc_node mm/slub.c:4364 [inline]
 __kvmalloc_node_noprof+0xa36/0x1530 mm/slub.c:5052
 kvmalloc_array_node_noprof include/linux/slab.h:1065 [inline]
 io_alloc_cache_init+0x53/0x150 io_uring/alloc_cache.c:25
 io_ring_ctx_alloc+0x617/0x14f0 io_uring/io_uring.c:337
 io_uring_create+0x32f/0x1400 io_uring/io_uring.c:3743
 io_uring_setup io_uring/io_uring.c:3890 [inline]
 __do_sys_io_uring_setup io_uring/io_uring.c:3924 [inline]
 __se_sys_io_uring_setup+0x572/0x590 io_uring/io_uring.c:3915
 __x64_sys_io_uring_setup+0x78/0xb0 io_uring/io_uring.c:3915
 x64_sys_call+0x35b4/0x3e20 arch/x86/include/generated/asm/syscalls_64.h:426
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd9/0x210 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

CPU: 0 UID: 0 PID: 14064 Comm: syz.4.2614 Tainted: G        W           6.16.0-syzkaller-12250-gc30a13538d9f #0 PREEMPT(none) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
=====================================================


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