==================================================================
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 ffff8881421e8a00 by task rcu_exp_gp_kthr/16
CPU: 0 PID: 16 Comm: rcu_exp_gp_kthr Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
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 kernel/softirq.c:680 [inline]
invoke_softirq kernel/softirq.c:497 [inline]
__irq_exit_rcu+0x52/0xf0 kernel/softirq.c:729
irq_exit_rcu+0x9/0x10 kernel/softirq.c:741
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline]
sysvec_apic_timer_interrupt+0xa9/0xc0 arch/x86/kernel/apic/apic.c:1118
asm_sysvec_apic_timer_interrupt+0x1b/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:finish_task_switch+0x173/0x7b0 kernel/sched/core.c:5302
Code: 80 3c 2b 00 74 08 4c 89 f7 e8 99 55 69 00 4d 8b 2e 4d 85 ed 0f 85 cd 00 00 00 4c 89 e7 e8 35 b1 b3 03 fb 49 8d 9f 48 0b 00 00 <48> 89 d8 48 c1 e8 03 49 bd 00 00 00 00 00 fc ff df 42 0f b6 04 28
RSP: 0018:ffffc90000107ca0 EFLAGS: 00000282
RAX: 0000000080000001 RBX: ffff888100327088 RCX: 0000000000000000
RDX: 0000000000000001 RSI: ffffffff85ca7ec0 RDI: 00000000ffffffff
RBP: ffffc90000107cf0 R08: ffffffff8701c687 R09: 1ffffffff0e038d0
R10: dffffc0000000000 R11: fffffbfff0e038d1 R12: ffff8881f6e37d80
R13: 0000000000000000 R14: ffff8881f6e388e0 R15: ffff888100326540
context_switch kernel/sched/core.c:5428 [inline]
__schedule+0xbae/0x1500 kernel/sched/core.c:6755
schedule+0xbd/0x170 kernel/sched/core.c:6831
kthread_worker_fn+0x3eb/0x770 kernel/kthread.c:844
kthread+0x281/0x320 kernel/kthread.c:386
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
Allocated by task 2669:
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+0x3c8/0xa20 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 2669:
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:1191
sock_ioctl+0x4bd/0x710 net/socket.c:1310
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:1191
sock_ioctl+0x4bd/0x710 net/socket.c:1310
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 ffff8881421e8000
which belongs to the cache kmalloc-8k of size 8192
The buggy address is located 2560 bytes inside of
8192-byte region [ffff8881421e8000, ffff8881421ea000)
The buggy address belongs to the physical page:
page:ffffea0005087a00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1421e8
head:ffffea0005087a00 order:3 compound_mapcount:0 compound_pincount:0
flags: 0x4000000000010200(slab|head|zone=1)
raw: 4000000000010200 ffffea0004636c00 dead000000000003 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 2252, tgid 2251 (syz.6.568), ts 87180309541, free_ts 85307657787
set_page_owner include/linux/page_owner.h:33 [inline]
post_alloc_hook+0x1f5/0x210 mm/page_alloc.c:2670
prep_new_page+0x1c/0x110 mm/page_alloc.c:2677
get_page_from_freelist+0x2d12/0x2d80 mm/page_alloc.c:4583
__alloc_pages+0x1fa/0x610 mm/page_alloc.c:5924
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
kmalloc_trace+0x29/0xb0 mm/slab_common.c:1028
kmalloc include/linux/slab.h:563 [inline]
audit_log_d_path+0xc6/0x240 kernel/audit.c:2151
audit_log_d_path_exe+0x42/0x70 kernel/audit.c:2222
audit_log_task+0x214/0x300 kernel/auditsc.c:2948
audit_seccomp+0x7f/0x160 kernel/auditsc.c:2995
seccomp_log kernel/seccomp.c:994 [inline]
__seccomp_filter+0x1830/0x1af0 kernel/seccomp.c:1310
__secure_computing+0xea/0x290 kernel/seccomp.c:1340
page last free stack trace:
reset_page_owner include/linux/page_owner.h:26 [inline]
free_pages_prepare mm/page_alloc.c:1578 [inline]
free_pcp_prepare mm/page_alloc.c:1652 [inline]
free_unref_page_prepare+0x742/0x750 mm/page_alloc.c:3618
free_unref_page+0x95/0x540 mm/page_alloc.c:3716
free_the_page mm/page_alloc.c:863 [inline]
__free_pages+0x67/0x100 mm/page_alloc.c:6014
free_pages+0x82/0x90 mm/page_alloc.c:6025
kasan_depopulate_vmalloc_pte+0x6b/0x90 mm/kasan/shadow.c:375
apply_to_pte_range mm/memory.c:2690 [inline]
apply_to_pmd_range mm/memory.c:2734 [inline]
apply_to_pud_range mm/memory.c:2770 [inline]
apply_to_p4d_range mm/memory.c:2806 [inline]
__apply_to_page_range+0x8de/0xc80 mm/memory.c:2842
apply_to_existing_page_range+0x38/0x50 mm/memory.c:2875
kasan_release_vmalloc+0x97/0xb0 mm/kasan/shadow.c:492
__purge_vmap_area_lazy+0xf15/0x1870 mm/vmalloc.c:1791
drain_vmap_area_work+0x3e/0xd0 mm/vmalloc.c:1820
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
Memory state around the buggy address:
ffff8881421e8900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8881421e8980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8881421e8a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff8881421e8a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8881421e8b00: 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: 0 PID: 16 Comm: rcu_exp_gp_kthr Tainted: G B syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
RIP: 0010:__queue_work+0x575/0xd30 kernel/workqueue.c:-1
Code: 39 2b 0f 84 b9 00 00 00 e8 18 45 29 00 4c 89 ff e8 30 fd 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 5c a1 6e 00 49 8b 7d 00 e8 c3 f8
RSP: 0018:ffffc90000007c70 EFLAGS: 00010046
RAX: 0000000000000000 RBX: 000000007fffffff RCX: ffff888100326540
RDX: 0000000000000100 RSI: 000000007fffffff RDI: 000000007fffffff
RBP: ffffc90000007d08 R08: 0000000000000007 R09: fffffffffffffffb
R10: dffffc0000000000 R11: ffffed102843d139 R12: dffffc0000000000
R13: 0000000000000000 R14: ffff8881421e89c8 R15: 0000000000000008
FS: 0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd53d5f7000 CR3: 0000000118f6a000 CR4: 00000000003526b0
DR0: 0000000000000008 DR1: 0000000000000002 DR2: 0000000000000081
DR3: ffffffffefffff14 DR6: 00000000ffff0ff0 DR7: 0000000000000400
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 kernel/softirq.c:680 [inline]
invoke_softirq kernel/softirq.c:497 [inline]
__irq_exit_rcu+0x52/0xf0 kernel/softirq.c:729
irq_exit_rcu+0x9/0x10 kernel/softirq.c:741
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline]
sysvec_apic_timer_interrupt+0xa9/0xc0 arch/x86/kernel/apic/apic.c:1118
asm_sysvec_apic_timer_interrupt+0x1b/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:finish_task_switch+0x173/0x7b0 kernel/sched/core.c:5302
Code: 80 3c 2b 00 74 08 4c 89 f7 e8 99 55 69 00 4d 8b 2e 4d 85 ed 0f 85 cd 00 00 00 4c 89 e7 e8 35 b1 b3 03 fb 49 8d 9f 48 0b 00 00 <48> 89 d8 48 c1 e8 03 49 bd 00 00 00 00 00 fc ff df 42 0f b6 04 28
RSP: 0018:ffffc90000107ca0 EFLAGS: 00000282
RAX: 0000000080000001 RBX: ffff888100327088 RCX: 0000000000000000
RDX: 0000000000000001 RSI: ffffffff85ca7ec0 RDI: 00000000ffffffff
RBP: ffffc90000107cf0 R08: ffffffff8701c687 R09: 1ffffffff0e038d0
R10: dffffc0000000000 R11: fffffbfff0e038d1 R12: ffff8881f6e37d80
R13: 0000000000000000 R14: ffff8881f6e388e0 R15: ffff888100326540
context_switch kernel/sched/core.c:5428 [inline]
__schedule+0xbae/0x1500 kernel/sched/core.c:6755
schedule+0xbd/0x170 kernel/sched/core.c:6831
kthread_worker_fn+0x3eb/0x770 kernel/kthread.c:844
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 45 29 00 4c 89 ff e8 30 fd 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 5c a1 6e 00 49 8b 7d 00 e8 c3 f8
RSP: 0018:ffffc90000007c70 EFLAGS: 00010046
RAX: 0000000000000000 RBX: 000000007fffffff RCX: ffff888100326540
RDX: 0000000000000100 RSI: 000000007fffffff RDI: 000000007fffffff
RBP: ffffc90000007d08 R08: 0000000000000007 R09: fffffffffffffffb
R10: dffffc0000000000 R11: ffffed102843d139 R12: dffffc0000000000
R13: 0000000000000000 R14: ffff8881421e89c8 R15: 0000000000000008
FS: 0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd53d5f7000 CR3: 0000000118f6a000 CR4: 00000000003526b0
DR0: 0000000000000008 DR1: 0000000000000002 DR2: 0000000000000081
DR3: ffffffffefffff14 DR6: 00000000ffff0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: 80 3c 2b 00 cmpb $0x0,(%rbx,%rbp,1)
4: 74 08 je 0xe
6: 4c 89 f7 mov %r14,%rdi
9: e8 99 55 69 00 call 0x6955a7
e: 4d 8b 2e mov (%r14),%r13
11: 4d 85 ed test %r13,%r13
14: 0f 85 cd 00 00 00 jne 0xe7
1a: 4c 89 e7 mov %r12,%rdi
1d: e8 35 b1 b3 03 call 0x3b3b157
22: fb sti
23: 49 8d 9f 48 0b 00 00 lea 0xb48(%r15),%rbx
* 2a: 48 89 d8 mov %rbx,%rax <-- trapping instruction
2d: 48 c1 e8 03 shr $0x3,%rax
31: 49 bd 00 00 00 00 00 movabs $0xdffffc0000000000,%r13
38: fc ff df
3b: 42 0f b6 04 28 movzbl (%rax,%r13,1),%eax