==================================================================
BUG: KASAN: use-after-free in hlist_move_list include/linux/list.h:1014 [inline]
BUG: KASAN: use-after-free in collect_expired_timers kernel/time/timer.c:1625 [inline]
BUG: KASAN: use-after-free in __run_timers+0x340/0x9f0 kernel/time/timer.c:1861
Write of size 8 at addr ffff888139fc0a00 by task kworker/u4:8/3294
CPU: 1 PID: 3294 Comm: kworker/u4:8 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: netns cleanup_net
Call Trace:
__dump_stack+0x21/0x24 lib/dump_stack.c:88
dump_stack_lvl+0x110/0x170 lib/dump_stack.c:106
print_address_description+0x71/0x200 mm/kasan/report.c:316
print_report+0x4a/0x60 mm/kasan/report.c:420
kasan_report+0x122/0x150 mm/kasan/report.c:524
__asan_report_store8_noabort+0x17/0x20 mm/kasan/report_generic.c:356
hlist_move_list include/linux/list.h:1014 [inline]
collect_expired_timers kernel/time/timer.c:1625 [inline]
__run_timers+0x340/0x9f0 kernel/time/timer.c:1861
run_timer_softirq+0x6a/0xf0 kernel/time/timer.c:1888
handle_softirqs+0x1d7/0x600 kernel/softirq.c:642
__do_softirq+0xb/0xd kernel/softirq.c:680
do_softirq+0xdc/0x130 kernel/softirq.c:524
__local_bh_enable_ip+0x75/0x80 kernel/softirq.c:448
__raw_spin_unlock_bh include/linux/spinlock_api_smp.h:167 [inline]
_raw_spin_unlock_bh+0x50/0x60 kernel/locking/spinlock.c:210
spin_unlock_bh include/linux/spinlock.h:396 [inline]
__fib6_clean_all net/ipv6/ip6_fib.c:2268 [inline]
fib6_flush_trees+0x25f/0x310 net/ipv6/ip6_fib.c:2291
rt_genid_bump_ipv6 include/net/net_namespace.h:535 [inline]
__ipv6_ifa_notify+0x8d5/0xe80 net/ipv6/addrconf.c:6270
addrconf_ifdown+0xe1e/0x1950 net/ipv6/addrconf.c:3948
addrconf_notify+0x39f/0xe40 net/ipv6/addrconf.c:-1
notifier_call_chain kernel/notifier.c:87 [inline]
raw_notifier_call_chain+0xa1/0x110 kernel/notifier.c:455
call_netdevice_notifiers_info net/core/dev.c:2009 [inline]
call_netdevice_notifiers_extack net/core/dev.c:2047 [inline]
call_netdevice_notifiers net/core/dev.c:2061 [inline]
dev_close_many+0x32e/0x4d0 net/core/dev.c:1609
unregister_netdevice_many+0x44f/0x18e0 net/core/dev.c:10941
sit_exit_batch_net+0x612/0x660 net/ipv6/sit.c:1888
ops_exit_list net/core/net_namespace.c:177 [inline]
cleanup_net+0x635/0xb10 net/core/net_namespace.c:604
process_one_work+0x71f/0xc40 kernel/workqueue.c:2302
worker_thread+0xa29/0x11e0 kernel/workqueue.c:2449
kthread+0x281/0x320 kernel/kthread.c:386
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
Allocated by task 3893:
kasan_save_stack mm/kasan/common.c:46 [inline]
kasan_set_track+0x4b/0x70 mm/kasan/common.c:53
kasan_save_alloc_info+0x25/0x30 mm/kasan/generic.c:505
____kasan_kmalloc mm/kasan/common.c:380 [inline]
__kasan_kmalloc+0x95/0xb0 mm/kasan/common.c:389
kasan_kmalloc include/linux/kasan.h:212 [inline]
__do_kmalloc_node mm/slab_common.c:938 [inline]
__kmalloc+0xb1/0x1e0 mm/slab_common.c:951
kmalloc include/linux/slab.h:568 [inline]
kzalloc include/linux/slab.h:699 [inline]
hci_alloc_dev_priv+0x27/0x1bd0 net/bluetooth/hci_core.c:2433
hci_alloc_dev include/net/bluetooth/hci_core.h:1505 [inline]
hci_uart_register_dev drivers/bluetooth/hci_ldisc.c:641 [inline]
hci_uart_set_proto drivers/bluetooth/hci_ldisc.c:719 [inline]
hci_uart_tty_ioctl+0x3d6/0xa20 drivers/bluetooth/hci_ldisc.c:774
tty_ioctl+0x8ef/0xc60 drivers/tty/tty_io.c:2785
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:870 [inline]
__se_sys_ioctl+0x12f/0x1b0 fs/ioctl.c:856
__x64_sys_ioctl+0x7b/0x90 fs/ioctl.c:856
x64_sys_call+0x58b/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:17
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
Freed by task 3893:
kasan_save_stack mm/kasan/common.c:46 [inline]
kasan_set_track+0x4b/0x70 mm/kasan/common.c:53
kasan_save_free_info+0x31/0x50 mm/kasan/generic.c:516
____kasan_slab_free+0x132/0x180 mm/kasan/common.c:242
__kasan_slab_free+0x11/0x20 mm/kasan/common.c:250
kasan_slab_free include/linux/kasan.h:178 [inline]
slab_free_hook mm/slub.c:1750 [inline]
slab_free_freelist_hook+0xc2/0x190 mm/slub.c:1776
slab_free mm/slub.c:3712 [inline]
__kmem_cache_free+0xb7/0x1b0 mm/slub.c:3728
kfree+0x6f/0xf0 mm/slab_common.c:990
hci_release_dev+0x12a3/0x13b0 net/bluetooth/hci_core.c:2761
bt_host_release+0x82/0x90 net/bluetooth/hci_sysfs.c:85
device_release+0xa4/0x1d0 drivers/base/core.c:-1
kobject_cleanup lib/kobject.c:681 [inline]
kobject_release lib/kobject.c:712 [inline]
kref_put include/linux/kref.h:65 [inline]
kobject_put+0x19d/0x280 lib/kobject.c:729
put_device+0x1f/0x30 drivers/base/core.c:3806
hci_dev_put include/net/bluetooth/hci_core.h:1465 [inline]
hci_dev_cmd+0x279/0x740 net/bluetooth/hci_core.c:795
hci_sock_ioctl+0x41e/0x7f0 net/bluetooth/hci_sock.c:1096
sock_do_ioctl+0x114/0x330 net/socket.c:1194
sock_ioctl+0x4ca/0x720 net/socket.c:1311
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:870 [inline]
__se_sys_ioctl+0x12f/0x1b0 fs/ioctl.c:856
__x64_sys_ioctl+0x7b/0x90 fs/ioctl.c:856
x64_sys_call+0x58b/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:17
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
Last potentially related work creation:
kasan_save_stack+0x3a/0x60 mm/kasan/common.c:46
__kasan_record_aux_stack+0xb6/0xc0 mm/kasan/generic.c:486
kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:496
insert_work+0x51/0x300 kernel/workqueue.c:1368
__queue_work+0x9b1/0xd30 kernel/workqueue.c:1527
queue_work_on+0xde/0x150 kernel/workqueue.c:1555
queue_work include/linux/workqueue.h:510 [inline]
hci_cmd_sync_run net/bluetooth/hci_sync.c:140 [inline]
__hci_cmd_sync_sk+0xa7f/0xd30 net/bluetooth/hci_sync.c:162
__hci_cmd_sync_status_sk net/bluetooth/hci_sync.c:253 [inline]
__hci_cmd_sync_status net/bluetooth/hci_sync.c:277 [inline]
hci_cmd_sync_status+0x53/0x120 net/bluetooth/hci_sync.c:288
hci_dev_cmd+0x648/0x740 net/bluetooth/hci_core.c:-1
hci_sock_ioctl+0x41e/0x7f0 net/bluetooth/hci_sock.c:1096
sock_do_ioctl+0x114/0x330 net/socket.c:1194
sock_ioctl+0x4ca/0x720 net/socket.c:1311
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:870 [inline]
__se_sys_ioctl+0x12f/0x1b0 fs/ioctl.c:856
__x64_sys_ioctl+0x7b/0x90 fs/ioctl.c:856
x64_sys_call+0x58b/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:17
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
Second to last potentially related work creation:
kasan_save_stack+0x3a/0x60 mm/kasan/common.c:46
__kasan_record_aux_stack+0xb6/0xc0 mm/kasan/generic.c:486
kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:496
insert_work+0x51/0x300 kernel/workqueue.c:1368
__queue_work+0x9b1/0xd30 kernel/workqueue.c:1527
queue_work_on+0xde/0x150 kernel/workqueue.c:1555
queue_work include/linux/workqueue.h:510 [inline]
hci_cmd_timeout+0x191/0x200 net/bluetooth/hci_core.c:1468
process_one_work+0x71f/0xc40 kernel/workqueue.c:2302
worker_thread+0xa29/0x11e0 kernel/workqueue.c:2449
kthread+0x281/0x320 kernel/kthread.c:386
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
The buggy address belongs to the object at ffff888139fc0000
which belongs to the cache kmalloc-8k of size 8192
The buggy address is located 2560 bytes inside of
8192-byte region [ffff888139fc0000, ffff888139fc2000)
The buggy address belongs to the physical page:
page:ffffea0004e7f000 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x139fc0
head:ffffea0004e7f000 order:3 compound_mapcount:0 compound_pincount:0
flags: 0x4000000000010200(slab|head|zone=1)
raw: 4000000000010200 ffffea0004466e00 dead000000000004 ffff888100043500
raw: 0000000000000000 0000000000020002 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 646, tgid 645 (syz.5.68), ts 41768483183, free_ts 0
set_page_owner include/linux/page_owner.h:33 [inline]
post_alloc_hook+0x1f5/0x210 mm/page_alloc.c:2643
prep_new_page+0x1c/0x110 mm/page_alloc.c:2650
get_page_from_freelist+0x2d12/0x2d80 mm/page_alloc.c:4554
__alloc_pages+0x1d9/0x480 mm/page_alloc.c:5868
alloc_slab_page+0x6e/0xf0 include/linux/gfp.h:-1
allocate_slab mm/slub.c:1967 [inline]
new_slab+0x98/0x3d0 mm/slub.c:2020
___slab_alloc+0x6bd/0xb20 mm/slub.c:3177
__slab_alloc+0x5e/0xa0 mm/slub.c:3263
slab_alloc_node mm/slub.c:3348 [inline]
__kmem_cache_alloc_node+0x203/0x2c0 mm/slub.c:3423
__do_kmalloc_node mm/slab_common.c:937 [inline]
__kmalloc+0xa1/0x1e0 mm/slab_common.c:951
kmalloc_array include/linux/slab.h:615 [inline]
mb_cache_create+0x187/0x5a0 fs/mbcache.c:370
ext4_xattr_create_cache+0x13/0x20 fs/ext4/xattr.c:3172
__ext4_fill_super fs/ext4/super.c:5331 [inline]
ext4_fill_super+0x53a8/0x7a40 fs/ext4/super.c:5650
get_tree_bdev+0x447/0x690 fs/super.c:1368
ext4_get_tree+0x1c/0x20 fs/ext4/super.c:5680
vfs_get_tree+0x9a/0x270 fs/super.c:1575
page_owner free stack trace missing
Memory state around the buggy address:
ffff888139fc0900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888139fc0980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888139fc0a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888139fc0a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888139fc0b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 1 PID: 3294 Comm: kworker/u4:8 Tainted: G B syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: netns cleanup_net
RIP: 0010:__queue_work+0x575/0xd30 kernel/workqueue.c:-1
Code: 39 2b 0f 84 b9 00 00 00 e8 18 47 29 00 4c 89 ff e8 10 31 b8 03 49 bc 00 00 00 00 00 fc ff df 4c 8b 6d d0 4c 89 e8 48 c1 e8 03 <42> 80 3c 20 00 74 08 4c 89 ef e8 cc 74 6e 00 49 8b 7d 00 e8 a3 2c
RSP: 0018:ffffc900001b0c90 EFLAGS: 00010046
RAX: 0000000000000000 RBX: 000000007fffffff RCX: ffff888112e12880
RDX: 0000000000000100 RSI: 000000007fffffff RDI: 000000007fffffff
RBP: ffffc900001b0d28 R08: 0000000000000007 R09: fffffffffffffffb
R10: dffffc0000000000 R11: ffffed10273f8139 R12: dffffc0000000000
R13: 0000000000000000 R14: ffff888139fc09c8 R15: 0000000000000008
FS: 0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f63d0c01d58 CR3: 000000012d171000 CR4: 00000000003506a0
Call Trace:
delayed_work_timer_fn+0x61/0x80 kernel/workqueue.c:1653
call_timer_fn+0x46/0x2a0 kernel/time/timer.c:1553
expire_timers kernel/time/timer.c:1599 [inline]
__run_timers+0x689/0x9f0 kernel/time/timer.c:1875
run_timer_softirq+0x6a/0xf0 kernel/time/timer.c:1888
handle_softirqs+0x1d7/0x600 kernel/softirq.c:642
__do_softirq+0xb/0xd kernel/softirq.c:680
do_softirq+0xdc/0x130 kernel/softirq.c:524
__local_bh_enable_ip+0x75/0x80 kernel/softirq.c:448
__raw_spin_unlock_bh include/linux/spinlock_api_smp.h:167 [inline]
_raw_spin_unlock_bh+0x50/0x60 kernel/locking/spinlock.c:210
spin_unlock_bh include/linux/spinlock.h:396 [inline]
__fib6_clean_all net/ipv6/ip6_fib.c:2268 [inline]
fib6_flush_trees+0x25f/0x310 net/ipv6/ip6_fib.c:2291
rt_genid_bump_ipv6 include/net/net_namespace.h:535 [inline]
__ipv6_ifa_notify+0x8d5/0xe80 net/ipv6/addrconf.c:6270
addrconf_ifdown+0xe1e/0x1950 net/ipv6/addrconf.c:3948
addrconf_notify+0x39f/0xe40 net/ipv6/addrconf.c:-1
notifier_call_chain kernel/notifier.c:87 [inline]
raw_notifier_call_chain+0xa1/0x110 kernel/notifier.c:455
call_netdevice_notifiers_info net/core/dev.c:2009 [inline]
call_netdevice_notifiers_extack net/core/dev.c:2047 [inline]
call_netdevice_notifiers net/core/dev.c:2061 [inline]
dev_close_many+0x32e/0x4d0 net/core/dev.c:1609
unregister_netdevice_many+0x44f/0x18e0 net/core/dev.c:10941
sit_exit_batch_net+0x612/0x660 net/ipv6/sit.c:1888
ops_exit_list net/core/net_namespace.c:177 [inline]
cleanup_net+0x635/0xb10 net/core/net_namespace.c:604
process_one_work+0x71f/0xc40 kernel/workqueue.c:2302
worker_thread+0xa29/0x11e0 kernel/workqueue.c:2449
kthread+0x281/0x320 kernel/kthread.c:386
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__queue_work+0x575/0xd30 kernel/workqueue.c:-1
Code: 39 2b 0f 84 b9 00 00 00 e8 18 47 29 00 4c 89 ff e8 10 31 b8 03 49 bc 00 00 00 00 00 fc ff df 4c 8b 6d d0 4c 89 e8 48 c1 e8 03 <42> 80 3c 20 00 74 08 4c 89 ef e8 cc 74 6e 00 49 8b 7d 00 e8 a3 2c
RSP: 0018:ffffc900001b0c90 EFLAGS: 00010046
RAX: 0000000000000000 RBX: 000000007fffffff RCX: ffff888112e12880
RDX: 0000000000000100 RSI: 000000007fffffff RDI: 000000007fffffff
RBP: ffffc900001b0d28 R08: 0000000000000007 R09: fffffffffffffffb
R10: dffffc0000000000 R11: ffffed10273f8139 R12: dffffc0000000000
R13: 0000000000000000 R14: ffff888139fc09c8 R15: 0000000000000008
FS: 0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f63d0c01d58 CR3: 000000012d171000 CR4: 00000000003506a0
----------------
Code disassembly (best guess):
0: 39 2b cmp %ebp,(%rbx)
2: 0f 84 b9 00 00 00 je 0xc1
8: e8 18 47 29 00 call 0x294725
d: 4c 89 ff mov %r15,%rdi
10: e8 10 31 b8 03 call 0x3b83125
15: 49 bc 00 00 00 00 00 movabs $0xdffffc0000000000,%r12
1c: fc ff df
1f: 4c 8b 6d d0 mov -0x30(%rbp),%r13
23: 4c 89 e8 mov %r13,%rax
26: 48 c1 e8 03 shr $0x3,%rax
* 2a: 42 80 3c 20 00 cmpb $0x0,(%rax,%r12,1) <-- trapping instruction
2f: 74 08 je 0x39
31: 4c 89 ef mov %r13,%rdi
34: e8 cc 74 6e 00 call 0x6e7505
39: 49 8b 7d 00 mov 0x0(%r13),%rdi
3d: e8 .byte 0xe8
3e: a3 .byte 0xa3
3f: 2c .byte 0x2c