[v6.1] INFO: rcu detected stall in sys_newfstat
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syzbot
Dec 13, 2025, 9:05:26 PM (2 days ago) Dec 13
to syzkaller...@googlegroups.com
Hello,
syzbot found the following issue on:
HEAD commit: 50cbba13faa2 Linux 6.1.159
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=15a709c2580000
kernel config: https://syzkaller.appspot.com/x/.config?x=6a5cbd268406bf43
dashboard link: https://syzkaller.appspot.com/bug?extid=9996dca5d58ea852ffaf
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/50ceb00b1b39/disk-50cbba13.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/ebb8883b9a29/vmlinux-50cbba13.xz
kernel image: https://storage.googleapis.com/syzbot-assets/7edc2a795f03/bzImage-50cbba13.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+9996dc...@syzkaller.appspotmail.com
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P4281/1:b..l P7806/1:b..l P4462/1:b..l P7807/1:b..l
(detected by 1, t=10502 jiffies, g=37805, q=414 ncpus=2)
task:modprobe state:R running task stack:25456 pid:7807 ppid:4351 flags:0x00004000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5244 [inline]
__schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6873
irqentry_exit+0x63/0x70 kernel/entry/common.c:439
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:lock_acquire+0x20f/0x490 kernel/locking/lockdep.c:5666
Code: 00 9c 8f 84 24 80 00 00 00 f6 84 24 81 00 00 00 02 0f 85 f5 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 44 3d 00 00 00 00 00 66 43 c7 44 3d 09 00 00 43 c6 44 3d 0b
RSP: 0018:ffffc90004d074a0 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 970c622b84f50a00
RDX: 0000000000000000 RSI: ffffffff8a6c1780 RDI: ffffffff8abef920
RBP: ffffc90004d075b8 R08: dffffc0000000000 R09: fffffbfff2119049
R10: fffffbfff2119049 R11: 1ffffffff2119048 R12: 0000000000000000
R13: 1ffff920009a0ea0 R14: 0000000000000246 R15: dffffc0000000000
rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
rcu_read_lock include/linux/rcupdate.h:791 [inline]
is_bpf_text_address+0x43/0x2a0 kernel/bpf/core.c:735
kernel_text_address+0x9c/0xd0 kernel/extable.c:125
__kernel_text_address+0x9/0x30 kernel/extable.c:79
unwind_get_return_address+0x49/0x80 arch/x86/kernel/unwind_orc.c:323
arch_stack_walk+0xf2/0x140 arch/x86/kernel/stacktrace.c:26
stack_trace_save+0x98/0xe0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:45 [inline]
kasan_set_track+0x4b/0x70 mm/kasan/common.c:52
____kasan_kmalloc mm/kasan/common.c:374 [inline]
__kasan_kmalloc+0x8e/0xa0 mm/kasan/common.c:383
kasan_kmalloc include/linux/kasan.h:211 [inline]
__do_kmalloc_node mm/slab_common.c:936 [inline]
__kmalloc+0xb0/0x240 mm/slab_common.c:949
kmalloc include/linux/slab.h:568 [inline]
tomoyo_realpath_from_path+0xdf/0x5d0 security/tomoyo/realpath.c:251
tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
tomoyo_path_perm+0x1fd/0x550 security/tomoyo/file.c:822
security_inode_getattr+0xcf/0x120 security/security.c:1361
vfs_getattr+0x26/0x3a0 fs/stat.c:158
vfs_fstat fs/stat.c:183 [inline]
__do_sys_newfstat fs/stat.c:447 [inline]
__se_sys_newfstat fs/stat.c:444 [inline]
__x64_sys_newfstat+0x102/0x1c0 fs/stat.c:444
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fa9fb7e2e87
RSP: 002b:00007ffc0fc0bf88 EFLAGS: 00000246 ORIG_RAX: 0000000000000005
RAX: ffffffffffffffda RBX: 00007fa9fb7f7310 RCX: 00007fa9fb7e2e87
RDX: 0000000000000000 RSI: 00007ffc0fc0c020 RDI: 0000000000000000
RBP: 00007ffc0fc0c0e0 R08: 00007fa9fb7bf0a0 R09: 00007fa9fb7f7310
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007ffc0fc0c180 R15: 0000000000000000
</TASK>
task:kworker/u4:13 state:R running task stack:21392 pid:4462 ppid:2 flags:0x00004000
Workqueue: bat_events batadv_nc_worker
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5244 [inline]
__schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
preempt_schedule_notrace+0xca/0x110 kernel/sched/core.c:6823
preempt_schedule_notrace_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:35
rcu_is_watching+0x76/0xa0 kernel/rcu/tree.c:722
rcu_read_unlock include/linux/rcupdate.h:820 [inline]
batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:412 [inline]
batadv_nc_worker+0x204/0x600 net/batman-adv/network-coding.c:719
process_one_work+0x898/0x1160 kernel/workqueue.c:2292
worker_thread+0xaa2/0x1250 kernel/workqueue.c:2439
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
</TASK>
task:modprobe state:R running task stack:25152 pid:7806 ppid:7033 flags:0x00004000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5244 [inline]
__schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6873
irqentry_exit+0x63/0x70 kernel/entry/common.c:439
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:27 [inline]
RIP: 0010:check_kcov_mode kernel/kcov.c:182 [inline]
RIP: 0010:write_comp_data kernel/kcov.c:245 [inline]
RIP: 0010:__sanitizer_cov_trace_cmp1+0xc/0x80 kernel/kcov.c:275
Code: 8d 7e 01 8b 89 fc 15 00 00 48 39 cf 73 08 48 89 3a 48 89 44 f2 08 c3 0f 1f 80 00 00 00 00 48 8b 04 24 65 48 8b 15 04 8f 81 7e <65> 8b 0d 05 8f 81 7e 81 e1 00 01 ff 00 74 11 81 f9 00 01 00 00 75
RSP: 0018:ffffc90004ddf678 EFLAGS: 00000246
RAX: ffffffff89fe4dff RBX: 0000000000000006 RCX: dffffc0000000000
RDX: ffff88802c6e0000 RSI: 000000000000000c RDI: 0000000000000006
RBP: ffffc90004ddf850 R08: ffff88802c6e0000 R09: 0000000000000003
R10: 0000000000000003 R11: 0000000000000000 R12: 000000000000000c
R13: ffff888067446480 R14: ffff888067446400 R15: 000000000000000c
mt_validate_nulls lib/maple_tree.c:7200 [inline]
mt_validate+0x45ef/0x4c90 lib/maple_tree.c:7249
validate_mm_mt+0xcd/0x420 mm/mmap.c:295
validate_mm+0xcc/0x2b0 mm/mmap.c:332
mmap_region+0x780/0x1c70 mm/mmap.c:2922
do_mmap+0x958/0xfd0 mm/mmap.c:1436
vm_mmap_pgoff+0x1b2/0x2b0 mm/util.c:520
ksys_mmap_pgoff+0x516/0x6f0 mm/mmap.c:1482
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f3688231242
RSP: 002b:00007fff957c5f88 EFLAGS: 00000206 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007f368815b000 RCX: 00007f3688231242
RDX: 0000000000000005 RSI: 0000000000086000 RDI: 00007f368815b000
RBP: 0000000000000812 R08: 0000000000000000 R09: 0000000000010000
R10: 0000000000000812 R11: 0000000000000206 R12: 00007fff957c5fd8
R13: 00007f368820d0c0 R14: 00007fff957c6390 R15: 00000ffff2af8bf4
</TASK>
task:udevd state:R running task stack:23040 pid:4281 ppid:3637 flags:0x00004002
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5244 [inline]
__schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:6730
preempt_schedule+0xa7/0xb0 kernel/sched/core.c:6754
preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34
unwind_next_frame+0x1892/0x20b0 arch/x86/kernel/unwind_orc.c:629
arch_stack_walk+0x10c/0x140 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x98/0xe0 kernel/stacktrace.c:122
save_stack+0xf3/0x1e0 mm/page_owner.c:127
__reset_page_owner+0x51/0x1a0 mm/page_owner.c:148
reset_page_owner include/linux/page_owner.h:24 [inline]
free_pages_prepare mm/page_alloc.c:1459 [inline]
free_pcp_prepare mm/page_alloc.c:1509 [inline]
free_unref_page_prepare+0x8b4/0x9a0 mm/page_alloc.c:3384
free_unref_page_list+0xbb/0x8e0 mm/page_alloc.c:3525
release_pages+0x1f92/0x2200 mm/swap.c:1035
__pagevec_release+0x6d/0xe0 mm/swap.c:1055
pagevec_release include/linux/pagevec.h:71 [inline]
folio_batch_release include/linux/pagevec.h:135 [inline]
shmem_undo_range+0x75b/0x2050 mm/shmem.c:946
shmem_truncate_range mm/shmem.c:1062 [inline]
shmem_evict_inode+0x248/0xa40 mm/shmem.c:1171
evict+0x485/0x870 fs/inode.c:705
__dentry_kill+0x431/0x650 fs/dcache.c:611
dentry_kill+0xb8/0x290 fs/dcache.c:-1
dput+0xfa/0x1d0 fs/dcache.c:918
__fput+0x5e0/0x920 fs/file_table.c:328
task_work_run+0x1ca/0x250 kernel/task_work.c:203
resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177
exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fb24d8a7407
RSP: 002b:00007ffca889da90 EFLAGS: 00000202 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 00007fb24e013880 RCX: 00007fb24d8a7407
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000008
RBP: 00007fb24e0136e8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000002
R13: 000055b4e63b4410 R14: 0000000000000008 R15: 000055b4e63b1830
</TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10637 jiffies! g37805 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: Possible timer handling issue on cpu=0 timer-softirq=14783
rcu: rcu_preempt kthread starved for 10638 jiffies! g37805 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=0
rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt state:I stack:27840 pid:16 ppid:2 flags:0x00004000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5244 [inline]
__schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
schedule+0xb9/0x180 kernel/sched/core.c:6637
schedule_timeout+0x15c/0x280 kernel/time/timer.c:2168
rcu_gp_fqs_loop+0x2f2/0x1310 kernel/rcu/tree.c:1706
rcu_gp_kthread+0x95/0x380 kernel/rcu/tree.c:1905
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
</TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 7801 Comm: syz.5.723 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:arch_irqs_disabled_flags arch/x86/include/asm/irqflags.h:125 [inline]
RIP: 0010:arch_irqs_disabled arch/x86/include/asm/irqflags.h:132 [inline]
RIP: 0010:seqcount_lockdep_reader_access+0x12e/0x1c0 include/linux/seqlock.h:104
Code: a8 b0 f1 ff 48 83 c4 08 48 c7 c7 48 47 94 8c 48 89 de e8 b5 32 f2 ff e8 e0 ea 15 00 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 <48> 8b 5c 24 20 48 89 de 48 81 e6 00 02 00 00 31 ff e8 8c 92 0f 00
RSP: 0018:ffffc900042379e0 EFLAGS: 00000046
RAX: b69b9c9fbb232200 RBX: ffffffff817151d1 RCX: b69b9c9fbb232200
RDX: 0000000000000001 RSI: ffffffff8a6c1780 RDI: ffffffff8abef920
RBP: ffffc90004237a88 R08: dffffc0000000000 R09: fffffbfff1bfe1c6
R10: fffffbfff1bfe1c6 R11: 1ffffffff1bfe1c5 R12: 0000000000000000
R13: dffffc0000000000 R14: 1ffff92000846f3c R15: dffffc0000000000
FS: 00007f4cba6a36c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055556f7934a8 CR3: 000000003bade000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
ktime_get+0x31/0x270 kernel/time/timekeeping.c:846
common_hrtimer_rearm+0x5d/0x110 kernel/time/posix-timers.c:303
posixtimer_rearm+0x131/0x340 kernel/time/posix-timers.c:329
dequeue_signal+0x1b6/0x4b0 kernel/signal.c:704
get_signal+0x547/0x1350 kernel/signal.c:2751
arch_do_signal_or_restart+0xb7/0x1240 arch/x86/kernel/signal.c:871
exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f4cb978f749
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:00007f4cba6a30e8 EFLAGS: 00000246
RAX: fffffffffffffffc RBX: 00007f4cb99e5fa8 RCX: 00007f4cb978f749
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f4cb99e5fa8
RBP: 00007f4cb99e5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4cb99e6038 R14: 00007ffcbad87c60 R15: 00007ffcbad87d48
</TASK>
---
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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:
#syz undup
syzbot found the following issue on:
HEAD commit: 50cbba13faa2 Linux 6.1.159
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=15a709c2580000
kernel config: https://syzkaller.appspot.com/x/.config?x=6a5cbd268406bf43
dashboard link: https://syzkaller.appspot.com/bug?extid=9996dca5d58ea852ffaf
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/50ceb00b1b39/disk-50cbba13.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/ebb8883b9a29/vmlinux-50cbba13.xz
kernel image: https://storage.googleapis.com/syzbot-assets/7edc2a795f03/bzImage-50cbba13.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+9996dc...@syzkaller.appspotmail.com
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P4281/1:b..l P7806/1:b..l P4462/1:b..l P7807/1:b..l
(detected by 1, t=10502 jiffies, g=37805, q=414 ncpus=2)
task:modprobe state:R running task stack:25456 pid:7807 ppid:4351 flags:0x00004000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5244 [inline]
__schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6873
irqentry_exit+0x63/0x70 kernel/entry/common.c:439
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:lock_acquire+0x20f/0x490 kernel/locking/lockdep.c:5666
Code: 00 9c 8f 84 24 80 00 00 00 f6 84 24 81 00 00 00 02 0f 85 f5 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 44 3d 00 00 00 00 00 66 43 c7 44 3d 09 00 00 43 c6 44 3d 0b
RSP: 0018:ffffc90004d074a0 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 970c622b84f50a00
RDX: 0000000000000000 RSI: ffffffff8a6c1780 RDI: ffffffff8abef920
RBP: ffffc90004d075b8 R08: dffffc0000000000 R09: fffffbfff2119049
R10: fffffbfff2119049 R11: 1ffffffff2119048 R12: 0000000000000000
R13: 1ffff920009a0ea0 R14: 0000000000000246 R15: dffffc0000000000
rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
rcu_read_lock include/linux/rcupdate.h:791 [inline]
is_bpf_text_address+0x43/0x2a0 kernel/bpf/core.c:735
kernel_text_address+0x9c/0xd0 kernel/extable.c:125
__kernel_text_address+0x9/0x30 kernel/extable.c:79
unwind_get_return_address+0x49/0x80 arch/x86/kernel/unwind_orc.c:323
arch_stack_walk+0xf2/0x140 arch/x86/kernel/stacktrace.c:26
stack_trace_save+0x98/0xe0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:45 [inline]
kasan_set_track+0x4b/0x70 mm/kasan/common.c:52
____kasan_kmalloc mm/kasan/common.c:374 [inline]
__kasan_kmalloc+0x8e/0xa0 mm/kasan/common.c:383
kasan_kmalloc include/linux/kasan.h:211 [inline]
__do_kmalloc_node mm/slab_common.c:936 [inline]
__kmalloc+0xb0/0x240 mm/slab_common.c:949
kmalloc include/linux/slab.h:568 [inline]
tomoyo_realpath_from_path+0xdf/0x5d0 security/tomoyo/realpath.c:251
tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
tomoyo_path_perm+0x1fd/0x550 security/tomoyo/file.c:822
security_inode_getattr+0xcf/0x120 security/security.c:1361
vfs_getattr+0x26/0x3a0 fs/stat.c:158
vfs_fstat fs/stat.c:183 [inline]
__do_sys_newfstat fs/stat.c:447 [inline]
__se_sys_newfstat fs/stat.c:444 [inline]
__x64_sys_newfstat+0x102/0x1c0 fs/stat.c:444
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fa9fb7e2e87
RSP: 002b:00007ffc0fc0bf88 EFLAGS: 00000246 ORIG_RAX: 0000000000000005
RAX: ffffffffffffffda RBX: 00007fa9fb7f7310 RCX: 00007fa9fb7e2e87
RDX: 0000000000000000 RSI: 00007ffc0fc0c020 RDI: 0000000000000000
RBP: 00007ffc0fc0c0e0 R08: 00007fa9fb7bf0a0 R09: 00007fa9fb7f7310
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007ffc0fc0c180 R15: 0000000000000000
</TASK>
task:kworker/u4:13 state:R running task stack:21392 pid:4462 ppid:2 flags:0x00004000
Workqueue: bat_events batadv_nc_worker
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5244 [inline]
__schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
preempt_schedule_notrace+0xca/0x110 kernel/sched/core.c:6823
preempt_schedule_notrace_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:35
rcu_is_watching+0x76/0xa0 kernel/rcu/tree.c:722
rcu_read_unlock include/linux/rcupdate.h:820 [inline]
batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:412 [inline]
batadv_nc_worker+0x204/0x600 net/batman-adv/network-coding.c:719
process_one_work+0x898/0x1160 kernel/workqueue.c:2292
worker_thread+0xaa2/0x1250 kernel/workqueue.c:2439
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
</TASK>
task:modprobe state:R running task stack:25152 pid:7806 ppid:7033 flags:0x00004000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5244 [inline]
__schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6873
irqentry_exit+0x63/0x70 kernel/entry/common.c:439
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:27 [inline]
RIP: 0010:check_kcov_mode kernel/kcov.c:182 [inline]
RIP: 0010:write_comp_data kernel/kcov.c:245 [inline]
RIP: 0010:__sanitizer_cov_trace_cmp1+0xc/0x80 kernel/kcov.c:275
Code: 8d 7e 01 8b 89 fc 15 00 00 48 39 cf 73 08 48 89 3a 48 89 44 f2 08 c3 0f 1f 80 00 00 00 00 48 8b 04 24 65 48 8b 15 04 8f 81 7e <65> 8b 0d 05 8f 81 7e 81 e1 00 01 ff 00 74 11 81 f9 00 01 00 00 75
RSP: 0018:ffffc90004ddf678 EFLAGS: 00000246
RAX: ffffffff89fe4dff RBX: 0000000000000006 RCX: dffffc0000000000
RDX: ffff88802c6e0000 RSI: 000000000000000c RDI: 0000000000000006
RBP: ffffc90004ddf850 R08: ffff88802c6e0000 R09: 0000000000000003
R10: 0000000000000003 R11: 0000000000000000 R12: 000000000000000c
R13: ffff888067446480 R14: ffff888067446400 R15: 000000000000000c
mt_validate_nulls lib/maple_tree.c:7200 [inline]
mt_validate+0x45ef/0x4c90 lib/maple_tree.c:7249
validate_mm_mt+0xcd/0x420 mm/mmap.c:295
validate_mm+0xcc/0x2b0 mm/mmap.c:332
mmap_region+0x780/0x1c70 mm/mmap.c:2922
do_mmap+0x958/0xfd0 mm/mmap.c:1436
vm_mmap_pgoff+0x1b2/0x2b0 mm/util.c:520
ksys_mmap_pgoff+0x516/0x6f0 mm/mmap.c:1482
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f3688231242
RSP: 002b:00007fff957c5f88 EFLAGS: 00000206 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007f368815b000 RCX: 00007f3688231242
RDX: 0000000000000005 RSI: 0000000000086000 RDI: 00007f368815b000
RBP: 0000000000000812 R08: 0000000000000000 R09: 0000000000010000
R10: 0000000000000812 R11: 0000000000000206 R12: 00007fff957c5fd8
R13: 00007f368820d0c0 R14: 00007fff957c6390 R15: 00000ffff2af8bf4
</TASK>
task:udevd state:R running task stack:23040 pid:4281 ppid:3637 flags:0x00004002
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5244 [inline]
__schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:6730
preempt_schedule+0xa7/0xb0 kernel/sched/core.c:6754
preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34
unwind_next_frame+0x1892/0x20b0 arch/x86/kernel/unwind_orc.c:629
arch_stack_walk+0x10c/0x140 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x98/0xe0 kernel/stacktrace.c:122
save_stack+0xf3/0x1e0 mm/page_owner.c:127
__reset_page_owner+0x51/0x1a0 mm/page_owner.c:148
reset_page_owner include/linux/page_owner.h:24 [inline]
free_pages_prepare mm/page_alloc.c:1459 [inline]
free_pcp_prepare mm/page_alloc.c:1509 [inline]
free_unref_page_prepare+0x8b4/0x9a0 mm/page_alloc.c:3384
free_unref_page_list+0xbb/0x8e0 mm/page_alloc.c:3525
release_pages+0x1f92/0x2200 mm/swap.c:1035
__pagevec_release+0x6d/0xe0 mm/swap.c:1055
pagevec_release include/linux/pagevec.h:71 [inline]
folio_batch_release include/linux/pagevec.h:135 [inline]
shmem_undo_range+0x75b/0x2050 mm/shmem.c:946
shmem_truncate_range mm/shmem.c:1062 [inline]
shmem_evict_inode+0x248/0xa40 mm/shmem.c:1171
evict+0x485/0x870 fs/inode.c:705
__dentry_kill+0x431/0x650 fs/dcache.c:611
dentry_kill+0xb8/0x290 fs/dcache.c:-1
dput+0xfa/0x1d0 fs/dcache.c:918
__fput+0x5e0/0x920 fs/file_table.c:328
task_work_run+0x1ca/0x250 kernel/task_work.c:203
resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177
exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fb24d8a7407
RSP: 002b:00007ffca889da90 EFLAGS: 00000202 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 00007fb24e013880 RCX: 00007fb24d8a7407
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000008
RBP: 00007fb24e0136e8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000002
R13: 000055b4e63b4410 R14: 0000000000000008 R15: 000055b4e63b1830
</TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10637 jiffies! g37805 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: Possible timer handling issue on cpu=0 timer-softirq=14783
rcu: rcu_preempt kthread starved for 10638 jiffies! g37805 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=0
rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt state:I stack:27840 pid:16 ppid:2 flags:0x00004000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5244 [inline]
__schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
schedule+0xb9/0x180 kernel/sched/core.c:6637
schedule_timeout+0x15c/0x280 kernel/time/timer.c:2168
rcu_gp_fqs_loop+0x2f2/0x1310 kernel/rcu/tree.c:1706
rcu_gp_kthread+0x95/0x380 kernel/rcu/tree.c:1905
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
</TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 7801 Comm: syz.5.723 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:arch_irqs_disabled_flags arch/x86/include/asm/irqflags.h:125 [inline]
RIP: 0010:arch_irqs_disabled arch/x86/include/asm/irqflags.h:132 [inline]
RIP: 0010:seqcount_lockdep_reader_access+0x12e/0x1c0 include/linux/seqlock.h:104
Code: a8 b0 f1 ff 48 83 c4 08 48 c7 c7 48 47 94 8c 48 89 de e8 b5 32 f2 ff e8 e0 ea 15 00 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 <48> 8b 5c 24 20 48 89 de 48 81 e6 00 02 00 00 31 ff e8 8c 92 0f 00
RSP: 0018:ffffc900042379e0 EFLAGS: 00000046
RAX: b69b9c9fbb232200 RBX: ffffffff817151d1 RCX: b69b9c9fbb232200
RDX: 0000000000000001 RSI: ffffffff8a6c1780 RDI: ffffffff8abef920
RBP: ffffc90004237a88 R08: dffffc0000000000 R09: fffffbfff1bfe1c6
R10: fffffbfff1bfe1c6 R11: 1ffffffff1bfe1c5 R12: 0000000000000000
R13: dffffc0000000000 R14: 1ffff92000846f3c R15: dffffc0000000000
FS: 00007f4cba6a36c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055556f7934a8 CR3: 000000003bade000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
ktime_get+0x31/0x270 kernel/time/timekeeping.c:846
common_hrtimer_rearm+0x5d/0x110 kernel/time/posix-timers.c:303
posixtimer_rearm+0x131/0x340 kernel/time/posix-timers.c:329
dequeue_signal+0x1b6/0x4b0 kernel/signal.c:704
get_signal+0x547/0x1350 kernel/signal.c:2751
arch_do_signal_or_restart+0xb7/0x1240 arch/x86/kernel/signal.c:871
exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f4cb978f749
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:00007f4cba6a30e8 EFLAGS: 00000246
RAX: fffffffffffffffc RBX: 00007f4cb99e5fa8 RCX: 00007f4cb978f749
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f4cb99e5fa8
RBP: 00007f4cb99e5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4cb99e6038 R14: 00007ffcbad87c60 R15: 00007ffcbad87d48
</TASK>
---
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