[v6.6] KASAN: slab-use-after-free Read in remove_wait_queue

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 3a8ababb8b6a Linux 6.6.101
git tree: linux-6.6.y
console output: https://syzkaller.appspot.com/x/log.txt?x=13b90042580000
kernel config: https://syzkaller.appspot.com/x/.config?x=a2bd95b6de4839b7
dashboard link: https://syzkaller.appspot.com/bug?extid=9c6891ee8c4cc1cac439
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/f06c672f5fa8/disk-3a8ababb.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/9af9b7afcdc5/vmlinux-3a8ababb.xz
kernel image: https://storage.googleapis.com/syzbot-assets/351a55aafa77/bzImage-3a8ababb.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+9c6891...@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: slab-use-after-free in __lock_acquire+0xff/0x7c80 kernel/locking/lockdep.c:5005
Read of size 8 at addr ffff88801d65e8b8 by task syz.5.288/7516

CPU: 1 PID: 7516 Comm: syz.5.288 Not tainted 6.6.101-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
<TASK>
dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106
print_address_description mm/kasan/report.c:364 [inline]
print_report+0xac/0x220 mm/kasan/report.c:468
kasan_report+0x117/0x150 mm/kasan/report.c:581
__lock_acquire+0xff/0x7c80 kernel/locking/lockdep.c:5005
lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0xa8/0xf0 kernel/locking/spinlock.c:162
remove_wait_queue+0x24/0x120 kernel/sched/wait.c:54
free_poll_entry fs/select.c:132 [inline]
poll_freewait+0xb1/0x240 fs/select.c:141
do_select+0x175b/0x1840 fs/select.c:609
core_sys_select+0x71c/0x950 fs/select.c:678
do_pselect fs/select.c:760 [inline]
__do_sys_pselect6 fs/select.c:801 [inline]
__se_sys_pselect6+0x285/0x310 fs/select.c:792
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fb77318eb69
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fb774053038 EFLAGS: 00000246 ORIG_RAX: 000000000000010e
RAX: ffffffffffffffda RBX: 00007fb7733b5fa0 RCX: 00007fb77318eb69
RDX: 0000000000000000 RSI: 0000200000000280 RDI: 0000000000000040
RBP: 00007fb773211df1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000200000000180 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fb7733b5fa0 R15: 00007fff1e063678
</TASK>

Allocated by task 7376:
kasan_save_stack mm/kasan/common.c:45 [inline]
kasan_set_track+0x4e/0x70 mm/kasan/common.c:52
____kasan_kmalloc mm/kasan/common.c:374 [inline]
__kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:383
kmalloc include/linux/slab.h:600 [inline]
kzalloc include/linux/slab.h:721 [inline]
__comedi_device_postconfig_async drivers/comedi/drivers.c:666 [inline]
__comedi_device_postconfig drivers/comedi/drivers.c:723 [inline]
comedi_device_postconfig+0x496/0xc50 drivers/comedi/drivers.c:758
comedi_device_attach+0x533/0x660 drivers/comedi/drivers.c:1000
do_devconfig_ioctl drivers/comedi/comedi_fops.c:855 [inline]
comedi_unlocked_ioctl+0x68d/0xf90 drivers/comedi/comedi_fops.c:2156
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:871 [inline]
__se_sys_ioctl+0xfd/0x170 fs/ioctl.c:857
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2

Freed by task 7519:
kasan_save_stack mm/kasan/common.c:45 [inline]
kasan_set_track+0x4e/0x70 mm/kasan/common.c:52
kasan_save_free_info+0x2e/0x50 mm/kasan/generic.c:522
____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:236
kasan_slab_free include/linux/kasan.h:164 [inline]
slab_free_hook mm/slub.c:1806 [inline]
slab_free_freelist_hook+0x130/0x1b0 mm/slub.c:1832
slab_free mm/slub.c:3816 [inline]
__kmem_cache_free+0xba/0x1f0 mm/slub.c:3829
comedi_device_detach_cleanup drivers/comedi/drivers.c:171 [inline]
comedi_device_detach+0x363/0x6f0 drivers/comedi/drivers.c:207
do_devconfig_ioctl drivers/comedi/comedi_fops.c:833 [inline]
comedi_unlocked_ioctl+0xbd0/0xf90 drivers/comedi/comedi_fops.c:2156
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:871 [inline]
__se_sys_ioctl+0xfd/0x170 fs/ioctl.c:857
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2

Last potentially related work creation:
kasan_save_stack+0x3e/0x60 mm/kasan/common.c:45
__kasan_record_aux_stack+0xaf/0xc0 mm/kasan/generic.c:492
kvfree_call_rcu+0xee/0x780 kernel/rcu/tree.c:3452
inetdev_event+0x2ae/0x15c0 net/ipv4/devinet.c:1623
notifier_call_chain+0x197/0x390 kernel/notifier.c:93
call_netdevice_notifiers_extack net/core/dev.c:2064 [inline]
call_netdevice_notifiers net/core/dev.c:2078 [inline]
dev_close_many+0x297/0x400 net/core/dev.c:1619
unregister_netdevice_many_notify+0x4c1/0x1810 net/core/dev.c:11047
unregister_netdevice_many net/core/dev.c:11130 [inline]
default_device_exit_batch+0x9cb/0xa60 net/core/dev.c:11608
ops_exit_list net/core/net_namespace.c:178 [inline]
cleanup_net+0x77f/0xb90 net/core/net_namespace.c:652
process_one_work kernel/workqueue.c:2634 [inline]
process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293

The buggy address belongs to the object at ffff88801d65e800
which belongs to the cache kmalloc-256 of size 256
The buggy address is located 184 bytes inside of
freed 256-byte region [ffff88801d65e800, ffff88801d65e900)

The buggy address belongs to the physical page:
page:ffffea0000759780 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1d65e
head:ffffea0000759780 order:1 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000840 ffff888017841b40 ffffea0000811780 dead000000000002
raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 1, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 5786, tgid 5786 (syz-executor), ts 86425704764, free_ts 86245935939
set_page_owner include/linux/page_owner.h:31 [inline]
post_alloc_hook+0x1cd/0x210 mm/page_alloc.c:1554
prep_new_page mm/page_alloc.c:1561 [inline]
get_page_from_freelist+0x195c/0x19f0 mm/page_alloc.c:3191
__alloc_pages+0x1e3/0x460 mm/page_alloc.c:4457
alloc_slab_page+0x5d/0x170 mm/slub.c:1876
allocate_slab mm/slub.c:2023 [inline]
new_slab+0x87/0x2e0 mm/slub.c:2076
___slab_alloc+0xc6d/0x12f0 mm/slub.c:3230
__slab_alloc mm/slub.c:3329 [inline]
__slab_alloc_node mm/slub.c:3382 [inline]
slab_alloc_node mm/slub.c:3475 [inline]
__kmem_cache_alloc_node+0x1a2/0x260 mm/slub.c:3524
__do_kmalloc_node mm/slab_common.c:1006 [inline]
__kmalloc+0xa4/0x240 mm/slab_common.c:1020
kmalloc include/linux/slab.h:604 [inline]
kzalloc include/linux/slab.h:721 [inline]
fib_create_info+0xa61/0x2460 net/ipv4/fib_semantics.c:1459
fib_table_insert+0xc7/0x1b50 net/ipv4/fib_trie.c:1217
fib_magic+0x2c5/0x390 net/ipv4/fib_frontend.c:1118
fib_add_ifaddr+0x144/0x5e0 net/ipv4/fib_frontend.c:1140
fib_netdev_event+0x389/0x490 net/ipv4/fib_frontend.c:1500
notifier_call_chain+0x197/0x390 kernel/notifier.c:93
call_netdevice_notifiers_extack net/core/dev.c:2064 [inline]
call_netdevice_notifiers net/core/dev.c:2078 [inline]
__dev_notify_flags+0x18e/0x2e0 net/core/dev.c:-1
dev_change_flags+0xe8/0x1a0 net/core/dev.c:8750
page last free stack trace:
reset_page_owner include/linux/page_owner.h:24 [inline]
free_pages_prepare mm/page_alloc.c:1154 [inline]
free_unref_page_prepare+0x7ce/0x8e0 mm/page_alloc.c:2336
free_unref_page+0x32/0x2e0 mm/page_alloc.c:2429
__slab_free+0x35e/0x410 mm/slub.c:3722
qlink_free mm/kasan/quarantine.c:166 [inline]
qlist_free_all+0x75/0xe0 mm/kasan/quarantine.c:185
kasan_quarantine_reduce+0x143/0x160 mm/kasan/quarantine.c:292
__kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:305
kasan_slab_alloc include/linux/kasan.h:188 [inline]
slab_post_alloc_hook+0x6e/0x4d0 mm/slab.h:767
slab_alloc_node mm/slub.c:3485 [inline]
slab_alloc mm/slub.c:3493 [inline]
__kmem_cache_alloc_lru mm/slub.c:3500 [inline]
kmem_cache_alloc_lru+0x115/0x2e0 mm/slub.c:3516
alloc_inode_sb include/linux/fs.h:2946 [inline]
sock_alloc_inode+0x28/0xc0 net/socket.c:308
alloc_inode fs/inode.c:261 [inline]
new_inode_pseudo+0x63/0x1d0 fs/inode.c:1049
sock_alloc net/socket.c:634 [inline]
__sock_create+0x12d/0x940 net/socket.c:1535
sock_create net/socket.c:1627 [inline]
__sys_socketpair+0x1c1/0x550 net/socket.c:1778
__do_sys_socketpair net/socket.c:1831 [inline]
__se_sys_socketpair net/socket.c:1828 [inline]
__x64_sys_socketpair+0x9b/0xb0 net/socket.c:1828
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2

Memory state around the buggy address:
ffff88801d65e780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff88801d65e800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88801d65e880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff88801d65e900: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff88801d65e980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================


---
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If you want to overwrite report's subsystems, reply with:
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If the report is a duplicate of another one, reply with:
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If you want to undo deduplication, reply with:
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[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: bb9c90ab9c5a Linux 6.6.102
git tree: linux-6.6.y
console output: https://syzkaller.appspot.com/x/log.txt?x=125fefbc580000
kernel config: https://syzkaller.appspot.com/x/.config?x=7b989b97a0687b0a

dashboard link: https://syzkaller.appspot.com/bug?extid=9c6891ee8c4cc1cac439
compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=168ebc42580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/44e2224124c3/disk-bb9c90ab.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/33e0aef7ff42/vmlinux-bb9c90ab.xz
kernel image: https://storage.googleapis.com/syzbot-assets/0515bc436228/bzImage-bb9c90ab.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+9c6891...@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: slab-use-after-free in __lock_acquire+0xff/0x7c80 kernel/locking/lockdep.c:5005

Read of size 8 at addr ffff88807b225cb8 by task syz.0.17/5950

CPU: 1 PID: 5950 Comm: syz.0.17 Not tainted 6.6.102-syzkaller #0

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
<TASK>
dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106
print_address_description mm/kasan/report.c:364 [inline]
print_report+0xac/0x220 mm/kasan/report.c:468
kasan_report+0x117/0x150 mm/kasan/report.c:581
__lock_acquire+0xff/0x7c80 kernel/locking/lockdep.c:5005
lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0xa8/0xf0 kernel/locking/spinlock.c:162
remove_wait_queue+0x24/0x120 kernel/sched/wait.c:54
free_poll_entry fs/select.c:132 [inline]
poll_freewait+0xb1/0x240 fs/select.c:141
do_select+0x175b/0x1840 fs/select.c:609
core_sys_select+0x71c/0x950 fs/select.c:678
do_pselect fs/select.c:760 [inline]
__do_sys_pselect6 fs/select.c:801 [inline]
__se_sys_pselect6+0x285/0x310 fs/select.c:792
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2

RIP: 0033:0x7f17c1f8ebe9

Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48

RSP: 002b:00007f17c2e85038 EFLAGS: 00000246 ORIG_RAX: 000000000000010e
RAX: ffffffffffffffda RBX: 00007f17c21b5fa0 RCX: 00007f17c1f8ebe9
RDX: 0000000000000000 RSI: 0000200000000100 RDI: 0000000000000040
RBP: 00007f17c2011e19 R08: 0000000000000000 R09: 0000000000000000
R10: 00002000000002c0 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f17c21b6038 R14: 00007f17c21b5fa0 R15: 00007ffe2dd59ce8
</TASK>

Allocated by task 5950:

kasan_save_stack mm/kasan/common.c:45 [inline]
kasan_set_track+0x4e/0x70 mm/kasan/common.c:52
____kasan_kmalloc mm/kasan/common.c:374 [inline]
__kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:383
kmalloc include/linux/slab.h:600 [inline]
kzalloc include/linux/slab.h:721 [inline]
__comedi_device_postconfig_async drivers/comedi/drivers.c:666 [inline]
__comedi_device_postconfig drivers/comedi/drivers.c:723 [inline]
comedi_device_postconfig+0x496/0xc50 drivers/comedi/drivers.c:758
comedi_device_attach+0x533/0x660 drivers/comedi/drivers.c:1000
do_devconfig_ioctl drivers/comedi/comedi_fops.c:855 [inline]
comedi_unlocked_ioctl+0x68d/0xf90 drivers/comedi/comedi_fops.c:2156
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:871 [inline]
__se_sys_ioctl+0xfd/0x170 fs/ioctl.c:857
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2

Freed by task 5951:

kasan_save_stack mm/kasan/common.c:45 [inline]
kasan_set_track+0x4e/0x70 mm/kasan/common.c:52
kasan_save_free_info+0x2e/0x50 mm/kasan/generic.c:522
____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:236
kasan_slab_free include/linux/kasan.h:164 [inline]
slab_free_hook mm/slub.c:1806 [inline]
slab_free_freelist_hook+0x130/0x1b0 mm/slub.c:1832
slab_free mm/slub.c:3816 [inline]
__kmem_cache_free+0xba/0x1f0 mm/slub.c:3829
comedi_device_detach_cleanup drivers/comedi/drivers.c:171 [inline]
comedi_device_detach+0x363/0x6f0 drivers/comedi/drivers.c:207
do_devconfig_ioctl drivers/comedi/comedi_fops.c:833 [inline]
comedi_unlocked_ioctl+0xbd0/0xf90 drivers/comedi/comedi_fops.c:2156
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:871 [inline]
__se_sys_ioctl+0xfd/0x170 fs/ioctl.c:857
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2

The buggy address belongs to the object at ffff88807b225c00

which belongs to the cache kmalloc-256 of size 256
The buggy address is located 184 bytes inside of

freed 256-byte region [ffff88807b225c00, ffff88807b225d00)

The buggy address belongs to the physical page:

page:ffffea0001ec8900 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7b224
head:ffffea0001ec8900 order:1 entire_mapcount:0 nr_pages_mapped:0 pincount:0

flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()

raw: 00fff00000000840 ffff888017841b40 dead000000000122 0000000000000000
raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000

page dumped because: kasan: bad access detected
page_owner tracks the page as allocated

page last allocated via order 1, migratetype Unmovable, gfp_mask 0x152820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_HARDWALL), pid 1094, tgid 1094 (kworker/u4:7), ts 78313279443, free_ts 78228037751

set_page_owner include/linux/page_owner.h:31 [inline]
post_alloc_hook+0x1cd/0x210 mm/page_alloc.c:1554
prep_new_page mm/page_alloc.c:1561 [inline]
get_page_from_freelist+0x195c/0x19f0 mm/page_alloc.c:3191
__alloc_pages+0x1e3/0x460 mm/page_alloc.c:4457

__alloc_pages_node include/linux/gfp.h:237 [inline]
alloc_slab_page+0x4f/0x170 mm/slub.c:1878

allocate_slab mm/slub.c:2023 [inline]
new_slab+0x87/0x2e0 mm/slub.c:2076
___slab_alloc+0xc6d/0x12f0 mm/slub.c:3230
__slab_alloc mm/slub.c:3329 [inline]
__slab_alloc_node mm/slub.c:3382 [inline]
slab_alloc_node mm/slub.c:3475 [inline]
__kmem_cache_alloc_node+0x1a2/0x260 mm/slub.c:3524
__do_kmalloc_node mm/slab_common.c:1006 [inline]

__kmalloc_node+0xa4/0x230 mm/slab_common.c:1014
kmalloc_array_node include/linux/slab.h:698 [inline]
kcalloc_node include/linux/slab.h:703 [inline]
memcg_alloc_slab_cgroups+0x87/0x130 mm/memcontrol.c:2899
account_slab mm/slab.h:641 [inline]
allocate_slab mm/slub.c:2041 [inline]
new_slab+0xc3/0x2e0 mm/slub.c:2076

___slab_alloc+0xc6d/0x12f0 mm/slub.c:3230
__slab_alloc mm/slub.c:3329 [inline]
__slab_alloc_node mm/slub.c:3382 [inline]
slab_alloc_node mm/slub.c:3475 [inline]

slab_alloc mm/slub.c:3493 [inline]
__kmem_cache_alloc_lru mm/slub.c:3500 [inline]

kmem_cache_alloc+0x1b7/0x2e0 mm/slub.c:3509
kmem_cache_zalloc include/linux/slab.h:711 [inline]
node_alloc net/ipv6/ip6_fib.c:186 [inline]
fib6_add_1+0xa28/0x1430 net/ipv6/ip6_fib.c:882
fib6_add+0x1da/0x3d20 net/ipv6/ip6_fib.c:1404
__ip6_ins_rt net/ipv6/route.c:1343 [inline]
ip6_ins_rt+0xc9/0x120 net/ipv6/route.c:1353
__ipv6_ifa_notify+0x62f/0xaa0 net/ipv6/addrconf.c:6247

page last free stack trace:
reset_page_owner include/linux/page_owner.h:24 [inline]
free_pages_prepare mm/page_alloc.c:1154 [inline]
free_unref_page_prepare+0x7ce/0x8e0 mm/page_alloc.c:2336
free_unref_page+0x32/0x2e0 mm/page_alloc.c:2429
__slab_free+0x35e/0x410 mm/slub.c:3722
qlink_free mm/kasan/quarantine.c:166 [inline]
qlist_free_all+0x75/0xe0 mm/kasan/quarantine.c:185
kasan_quarantine_reduce+0x143/0x160 mm/kasan/quarantine.c:292
__kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:305
kasan_slab_alloc include/linux/kasan.h:188 [inline]
slab_post_alloc_hook+0x6e/0x4d0 mm/slab.h:767
slab_alloc_node mm/slub.c:3485 [inline]

kmem_cache_alloc_node+0x150/0x330 mm/slub.c:3530
__alloc_skb+0x108/0x2c0 net/core/skbuff.c:640
alloc_skb include/linux/skbuff.h:1284 [inline]
nlmsg_new include/net/netlink.h:999 [inline]
inet_netconf_notify_devconf+0x173/0x230 net/ipv4/devinet.c:2150
__devinet_sysctl_unregister net/ipv4/devinet.c:2661 [inline]
devinet_exit_net+0x111/0x220 net/ipv4/devinet.c:2801
ops_exit_list net/core/net_namespace.c:173 [inline]
cleanup_net+0x6f4/0xb90 net/core/net_namespace.c:652

process_one_work kernel/workqueue.c:2634 [inline]
process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152

Memory state around the buggy address:

ffff88807b225b80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff88807b225c00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88807b225c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff88807b225d00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff88807b225d80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================


---
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[syzbot]

Auto-closing this bug as obsolete.
No recent activity, existing reproducers are no longer triggering the issue.