[v5.15] INFO: rcu detected stall in dput (3)
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syzbot
Dec 9, 2024, 12:03:26 PM12/9/24
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Hello,
syzbot found the following issue on:
HEAD commit: 0a51d2d4527b Linux 5.15.173
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=161954df980000
kernel config: https://syzkaller.appspot.com/x/.config?x=48dad5136d11d5fc
dashboard link: https://syzkaller.appspot.com/bug?extid=593324eabd9eef11e831
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/df502ed32946/disk-0a51d2d4.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/a6f49f24ceaa/vmlinux-0a51d2d4.xz
kernel image: https://storage.googleapis.com/syzbot-assets/f45db4b68abf/bzImage-0a51d2d4.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+593324...@syzkaller.appspotmail.com
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 1-...!: (0 ticks this GP) idle=ef3/1/0x4000000000000000 softirq=36744/36744 fqs=0
(detected by 0, t=10502 jiffies, g=47525, q=226)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 13224 Comm: syz.2.2819 Not tainted 5.15.173-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:__kasan_check_read+0x6/0x10 mm/kasan/shadow.c:31
Code: 41 5e 41 5f 5d c3 48 c7 c7 57 e0 3c 8c eb 0a 48 c7 c7 8f e0 3c 8c 4c 89 fe e8 66 25 73 08 31 db eb d7 cc cc 89 f6 48 8b 0c 24 <31> d2 e9 63 ef ff ff 0f 1f 00 89 f6 48 8b 0c 24 ba 01 00 00 00 e9
RSP: 0018:ffffc90000dd0a10 EFLAGS: 00000006
RAX: 0000000000000024 RBX: 0000000000000910 RCX: ffffffff81632d68
RDX: 0000000000000008 RSI: 0000000000000008 RDI: ffffffff90988220
RBP: 0000000000000008 R08: dffffc0000000000 R09: fffffbfff2131045
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000000
R13: dffffc0000000000 R14: 0000000000000100 R15: ffff88802a57c670
FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055555f4bd808 CR3: 00000000641bc000 CR4: 00000000003526e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<NMI>
</NMI>
<IRQ>
instrument_atomic_read include/linux/instrumented.h:71 [inline]
test_bit include/asm-generic/bitops/instrumented-non-atomic.h:134 [inline]
hlock_class kernel/locking/lockdep.c:197 [inline]
mark_lock+0x98/0x340 kernel/locking/lockdep.c:4569
mark_usage kernel/locking/lockdep.c:4512 [inline]
__lock_acquire+0xc97/0x1ff0 kernel/locking/lockdep.c:4966
lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
__raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
_raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154
spin_lock include/linux/spinlock.h:363 [inline]
advance_sched+0x47/0x940 net/sched/sch_taprio.c:716
__run_hrtimer kernel/time/hrtimer.c:1688 [inline]
__hrtimer_run_queues+0x598/0xcf0 kernel/time/hrtimer.c:1752
hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1814
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline]
__sysvec_apic_timer_interrupt+0x13b/0x4b0 arch/x86/kernel/apic/apic.c:1114
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:stack_trace_consume_entry+0xed/0x270 kernel/stacktrace.c:93
Code: 00 00 00 00 00 fc ff df 48 8b 1b 45 8d 70 01 41 0f b6 04 17 84 c0 0f 85 2d 01 00 00 45 89 31 4a 8d 1c c3 48 89 d8 48 c1 e8 03 <80> 3c 10 00 74 1a 4d 89 cf 48 89 df 49 89 d6 49 89 f5 e8 dc 41 5c
RSP: 0018:ffffc900033cecf0 EFLAGS: 00000a02
RAX: 1ffff92000679de9 RBX: ffffc900033cef48 RCX: 0000000080000000
RDX: dffffc0000000000 RSI: ffffffff81dba718 RDI: ffffc900033cee2c
RBP: ffffc900033cee28 R08: 0000000000000009 R09: ffffc900033cee30
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff92000679dc5
R13: 1ffff92000679dc5 R14: 000000000000000a R15: 1ffff92000679dc6
arch_stack_walk+0x101/0x140 arch/x86/kernel/stacktrace.c:27
stack_trace_save+0x113/0x1c0 kernel/stacktrace.c:122
save_stack+0xf6/0x1e0 mm/page_owner.c:119
__reset_page_owner+0x52/0x180 mm/page_owner.c:140
reset_page_owner include/linux/page_owner.h:24 [inline]
free_pages_prepare mm/page_alloc.c:1340 [inline]
free_pcp_prepare mm/page_alloc.c:1391 [inline]
free_unref_page_prepare+0xc34/0xcf0 mm/page_alloc.c:3317
free_unref_page_list+0x1f7/0x8e0 mm/page_alloc.c:3433
release_pages+0x1bb9/0x1f40 mm/swap.c:963
__pagevec_release+0x80/0xf0 mm/swap.c:983
pagevec_release include/linux/pagevec.h:81 [inline]
shmem_undo_range+0x67a/0x1b50 mm/shmem.c:964
shmem_truncate_range mm/shmem.c:1063 [inline]
shmem_evict_inode+0x21b/0xa00 mm/shmem.c:1147
evict+0x529/0x930 fs/inode.c:622
__dentry_kill+0x436/0x650 fs/dcache.c:586
dentry_kill+0xbb/0x290
dput+0xd8/0x1a0 fs/dcache.c:893
__fput+0x636/0x8e0 fs/file_table.c:288
task_work_run+0x129/0x1a0 kernel/task_work.c:188
exit_task_work include/linux/task_work.h:33 [inline]
do_exit+0x6a3/0x2480 kernel/exit.c:874
do_group_exit+0x144/0x310 kernel/exit.c:996
get_signal+0xc66/0x14e0 kernel/signal.c:2900
arch_do_signal_or_restart+0xc3/0x1890 arch/x86/kernel/signal.c:867
handle_signal_work kernel/entry/common.c:154 [inline]
exit_to_user_mode_loop+0x97/0x130 kernel/entry/common.c:178
exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214
__syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
syscall_exit_to_user_mode+0x5d/0x240 kernel/entry/common.c:307
do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fe9c994eed9
Code: Unable to access opcode bytes at RIP 0x7fe9c994eeaf.
RSP: 002b:00007fe9c77a4058 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: 0000000000010106 RBX: 00007fe9c9b15080 RCX: 00007fe9c994eed9
RDX: 0000000000010106 RSI: 00000000200000c0 RDI: 0000000000000003
RBP: 00007fe9c99c2cc8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fe9c9b15080 R15: 00007ffd41c3dce8
</TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g47525 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: Possible timer handling issue on cpu=1 timer-softirq=40621
rcu: rcu_preempt kthread starved for 10502 jiffies! g47525 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=1
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:27064 pid: 15 ppid: 2 flags:0x00004000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5027 [inline]
__schedule+0x12c4/0x45b0 kernel/sched/core.c:6373
schedule+0x11b/0x1f0 kernel/sched/core.c:6456
schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1914
rcu_gp_fqs_loop+0x2bf/0x1080 kernel/rcu/tree.c:1972
rcu_gp_kthread+0xa4/0x360 kernel/rcu/tree.c:2145
kthread+0x3f6/0x4f0 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
</TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 13224 Comm: syz.2.2819 Not tainted 5.15.173-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:kasan_check_range+0x1ac/0x290 mm/kasan/generic.c:189
Code: 4c 89 d5 48 8d 5d 07 48 85 ed 48 0f 49 dd 48 83 e3 f8 48 29 dd 74 12 41 80 39 00 0f 85 a2 00 00 00 49 ff c1 48 ff cd 75 ee 5b <41> 5e 41 5f 5d c3 45 84 f6 75 61 41 f7 c6 00 ff 00 00 75 5d 41 f7
RSP: 0018:ffffc90000dd0b40 EFLAGS: 00000056
RAX: 0000000000000001 RBX: 0000000000000001 RCX: ffffffff8162bd7c
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8e0a58a8
RBP: 0000000000000001 R08: dffffc0000000000 R09: fffffbfff1c14b16
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff920001ba174
R13: dffffc0000000000 R14: fffffbfff1c14b16 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055555f4bd808 CR3: 00000000641bc000 CR4: 00000000003526e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<NMI>
</NMI>
<IRQ>
instrument_atomic_read include/linux/instrumented.h:71 [inline]
test_bit include/asm-generic/bitops/instrumented-non-atomic.h:134 [inline]
cpumask_test_cpu include/linux/cpumask.h:344 [inline]
cpu_online include/linux/cpumask.h:895 [inline]
trace_lock_acquire include/trace/events/lock.h:13 [inline]
lock_acquire+0xcc/0x4f0 kernel/locking/lockdep.c:5594
__raw_spin_lock_irq include/linux/spinlock_api_smp.h:128 [inline]
_raw_spin_lock_irq+0xcf/0x110 kernel/locking/spinlock.c:170
__run_hrtimer kernel/time/hrtimer.c:1692 [inline]
__hrtimer_run_queues+0x662/0xcf0 kernel/time/hrtimer.c:1752
hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1814
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline]
__sysvec_apic_timer_interrupt+0x13b/0x4b0 arch/x86/kernel/apic/apic.c:1114
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:stack_trace_consume_entry+0xed/0x270 kernel/stacktrace.c:93
Code: 00 00 00 00 00 fc ff df 48 8b 1b 45 8d 70 01 41 0f b6 04 17 84 c0 0f 85 2d 01 00 00 45 89 31 4a 8d 1c c3 48 89 d8 48 c1 e8 03 <80> 3c 10 00 74 1a 4d 89 cf 48 89 df 49 89 d6 49 89 f5 e8 dc 41 5c
RSP: 0018:ffffc900033cecf0 EFLAGS: 00000a02
RAX: 1ffff92000679de9 RBX: ffffc900033cef48 RCX: 0000000080000000
RDX: dffffc0000000000 RSI: ffffffff81dba718 RDI: ffffc900033cee2c
RBP: ffffc900033cee28 R08: 0000000000000009 R09: ffffc900033cee30
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff92000679dc5
R13: 1ffff92000679dc5 R14: 000000000000000a R15: 1ffff92000679dc6
arch_stack_walk+0x101/0x140 arch/x86/kernel/stacktrace.c:27
stack_trace_save+0x113/0x1c0 kernel/stacktrace.c:122
save_stack+0xf6/0x1e0 mm/page_owner.c:119
__reset_page_owner+0x52/0x180 mm/page_owner.c:140
reset_page_owner include/linux/page_owner.h:24 [inline]
free_pages_prepare mm/page_alloc.c:1340 [inline]
free_pcp_prepare mm/page_alloc.c:1391 [inline]
free_unref_page_prepare+0xc34/0xcf0 mm/page_alloc.c:3317
free_unref_page_list+0x1f7/0x8e0 mm/page_alloc.c:3433
release_pages+0x1bb9/0x1f40 mm/swap.c:963
__pagevec_release+0x80/0xf0 mm/swap.c:983
pagevec_release include/linux/pagevec.h:81 [inline]
shmem_undo_range+0x67a/0x1b50 mm/shmem.c:964
shmem_truncate_range mm/shmem.c:1063 [inline]
shmem_evict_inode+0x21b/0xa00 mm/shmem.c:1147
evict+0x529/0x930 fs/inode.c:622
__dentry_kill+0x436/0x650 fs/dcache.c:586
dentry_kill+0xbb/0x290
dput+0xd8/0x1a0 fs/dcache.c:893
__fput+0x636/0x8e0 fs/file_table.c:288
task_work_run+0x129/0x1a0 kernel/task_work.c:188
exit_task_work include/linux/task_work.h:33 [inline]
do_exit+0x6a3/0x2480 kernel/exit.c:874
do_group_exit+0x144/0x310 kernel/exit.c:996
get_signal+0xc66/0x14e0 kernel/signal.c:2900
arch_do_signal_or_restart+0xc3/0x1890 arch/x86/kernel/signal.c:867
handle_signal_work kernel/entry/common.c:154 [inline]
exit_to_user_mode_loop+0x97/0x130 kernel/entry/common.c:178
exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214
__syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
syscall_exit_to_user_mode+0x5d/0x240 kernel/entry/common.c:307
do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fe9c994eed9
Code: Unable to access opcode bytes at RIP 0x7fe9c994eeaf.
RSP: 002b:00007fe9c77a4058 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: 0000000000010106 RBX: 00007fe9c9b15080 RCX: 00007fe9c994eed9
RDX: 0000000000010106 RSI: 00000000200000c0 RDI: 0000000000000003
RBP: 00007fe9c99c2cc8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fe9c9b15080 R15: 00007ffd41c3dce8
</TASK>
---
This report is generated by a bot. It may contain errors.
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If you want to undo deduplication, reply with:
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syzbot found the following issue on:
HEAD commit: 0a51d2d4527b Linux 5.15.173
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=161954df980000
kernel config: https://syzkaller.appspot.com/x/.config?x=48dad5136d11d5fc
dashboard link: https://syzkaller.appspot.com/bug?extid=593324eabd9eef11e831
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/df502ed32946/disk-0a51d2d4.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/a6f49f24ceaa/vmlinux-0a51d2d4.xz
kernel image: https://storage.googleapis.com/syzbot-assets/f45db4b68abf/bzImage-0a51d2d4.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+593324...@syzkaller.appspotmail.com
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 1-...!: (0 ticks this GP) idle=ef3/1/0x4000000000000000 softirq=36744/36744 fqs=0
(detected by 0, t=10502 jiffies, g=47525, q=226)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 13224 Comm: syz.2.2819 Not tainted 5.15.173-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:__kasan_check_read+0x6/0x10 mm/kasan/shadow.c:31
Code: 41 5e 41 5f 5d c3 48 c7 c7 57 e0 3c 8c eb 0a 48 c7 c7 8f e0 3c 8c 4c 89 fe e8 66 25 73 08 31 db eb d7 cc cc 89 f6 48 8b 0c 24 <31> d2 e9 63 ef ff ff 0f 1f 00 89 f6 48 8b 0c 24 ba 01 00 00 00 e9
RSP: 0018:ffffc90000dd0a10 EFLAGS: 00000006
RAX: 0000000000000024 RBX: 0000000000000910 RCX: ffffffff81632d68
RDX: 0000000000000008 RSI: 0000000000000008 RDI: ffffffff90988220
RBP: 0000000000000008 R08: dffffc0000000000 R09: fffffbfff2131045
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000000
R13: dffffc0000000000 R14: 0000000000000100 R15: ffff88802a57c670
FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055555f4bd808 CR3: 00000000641bc000 CR4: 00000000003526e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<NMI>
</NMI>
<IRQ>
instrument_atomic_read include/linux/instrumented.h:71 [inline]
test_bit include/asm-generic/bitops/instrumented-non-atomic.h:134 [inline]
hlock_class kernel/locking/lockdep.c:197 [inline]
mark_lock+0x98/0x340 kernel/locking/lockdep.c:4569
mark_usage kernel/locking/lockdep.c:4512 [inline]
__lock_acquire+0xc97/0x1ff0 kernel/locking/lockdep.c:4966
lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
__raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
_raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154
spin_lock include/linux/spinlock.h:363 [inline]
advance_sched+0x47/0x940 net/sched/sch_taprio.c:716
__run_hrtimer kernel/time/hrtimer.c:1688 [inline]
__hrtimer_run_queues+0x598/0xcf0 kernel/time/hrtimer.c:1752
hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1814
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline]
__sysvec_apic_timer_interrupt+0x13b/0x4b0 arch/x86/kernel/apic/apic.c:1114
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:stack_trace_consume_entry+0xed/0x270 kernel/stacktrace.c:93
Code: 00 00 00 00 00 fc ff df 48 8b 1b 45 8d 70 01 41 0f b6 04 17 84 c0 0f 85 2d 01 00 00 45 89 31 4a 8d 1c c3 48 89 d8 48 c1 e8 03 <80> 3c 10 00 74 1a 4d 89 cf 48 89 df 49 89 d6 49 89 f5 e8 dc 41 5c
RSP: 0018:ffffc900033cecf0 EFLAGS: 00000a02
RAX: 1ffff92000679de9 RBX: ffffc900033cef48 RCX: 0000000080000000
RDX: dffffc0000000000 RSI: ffffffff81dba718 RDI: ffffc900033cee2c
RBP: ffffc900033cee28 R08: 0000000000000009 R09: ffffc900033cee30
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff92000679dc5
R13: 1ffff92000679dc5 R14: 000000000000000a R15: 1ffff92000679dc6
arch_stack_walk+0x101/0x140 arch/x86/kernel/stacktrace.c:27
stack_trace_save+0x113/0x1c0 kernel/stacktrace.c:122
save_stack+0xf6/0x1e0 mm/page_owner.c:119
__reset_page_owner+0x52/0x180 mm/page_owner.c:140
reset_page_owner include/linux/page_owner.h:24 [inline]
free_pages_prepare mm/page_alloc.c:1340 [inline]
free_pcp_prepare mm/page_alloc.c:1391 [inline]
free_unref_page_prepare+0xc34/0xcf0 mm/page_alloc.c:3317
free_unref_page_list+0x1f7/0x8e0 mm/page_alloc.c:3433
release_pages+0x1bb9/0x1f40 mm/swap.c:963
__pagevec_release+0x80/0xf0 mm/swap.c:983
pagevec_release include/linux/pagevec.h:81 [inline]
shmem_undo_range+0x67a/0x1b50 mm/shmem.c:964
shmem_truncate_range mm/shmem.c:1063 [inline]
shmem_evict_inode+0x21b/0xa00 mm/shmem.c:1147
evict+0x529/0x930 fs/inode.c:622
__dentry_kill+0x436/0x650 fs/dcache.c:586
dentry_kill+0xbb/0x290
dput+0xd8/0x1a0 fs/dcache.c:893
__fput+0x636/0x8e0 fs/file_table.c:288
task_work_run+0x129/0x1a0 kernel/task_work.c:188
exit_task_work include/linux/task_work.h:33 [inline]
do_exit+0x6a3/0x2480 kernel/exit.c:874
do_group_exit+0x144/0x310 kernel/exit.c:996
get_signal+0xc66/0x14e0 kernel/signal.c:2900
arch_do_signal_or_restart+0xc3/0x1890 arch/x86/kernel/signal.c:867
handle_signal_work kernel/entry/common.c:154 [inline]
exit_to_user_mode_loop+0x97/0x130 kernel/entry/common.c:178
exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214
__syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
syscall_exit_to_user_mode+0x5d/0x240 kernel/entry/common.c:307
do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fe9c994eed9
Code: Unable to access opcode bytes at RIP 0x7fe9c994eeaf.
RSP: 002b:00007fe9c77a4058 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: 0000000000010106 RBX: 00007fe9c9b15080 RCX: 00007fe9c994eed9
RDX: 0000000000010106 RSI: 00000000200000c0 RDI: 0000000000000003
RBP: 00007fe9c99c2cc8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fe9c9b15080 R15: 00007ffd41c3dce8
</TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g47525 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: Possible timer handling issue on cpu=1 timer-softirq=40621
rcu: rcu_preempt kthread starved for 10502 jiffies! g47525 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=1
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:27064 pid: 15 ppid: 2 flags:0x00004000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5027 [inline]
__schedule+0x12c4/0x45b0 kernel/sched/core.c:6373
schedule+0x11b/0x1f0 kernel/sched/core.c:6456
schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1914
rcu_gp_fqs_loop+0x2bf/0x1080 kernel/rcu/tree.c:1972
rcu_gp_kthread+0xa4/0x360 kernel/rcu/tree.c:2145
kthread+0x3f6/0x4f0 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
</TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 13224 Comm: syz.2.2819 Not tainted 5.15.173-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:kasan_check_range+0x1ac/0x290 mm/kasan/generic.c:189
Code: 4c 89 d5 48 8d 5d 07 48 85 ed 48 0f 49 dd 48 83 e3 f8 48 29 dd 74 12 41 80 39 00 0f 85 a2 00 00 00 49 ff c1 48 ff cd 75 ee 5b <41> 5e 41 5f 5d c3 45 84 f6 75 61 41 f7 c6 00 ff 00 00 75 5d 41 f7
RSP: 0018:ffffc90000dd0b40 EFLAGS: 00000056
RAX: 0000000000000001 RBX: 0000000000000001 RCX: ffffffff8162bd7c
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8e0a58a8
RBP: 0000000000000001 R08: dffffc0000000000 R09: fffffbfff1c14b16
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff920001ba174
R13: dffffc0000000000 R14: fffffbfff1c14b16 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055555f4bd808 CR3: 00000000641bc000 CR4: 00000000003526e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<NMI>
</NMI>
<IRQ>
instrument_atomic_read include/linux/instrumented.h:71 [inline]
test_bit include/asm-generic/bitops/instrumented-non-atomic.h:134 [inline]
cpumask_test_cpu include/linux/cpumask.h:344 [inline]
cpu_online include/linux/cpumask.h:895 [inline]
trace_lock_acquire include/trace/events/lock.h:13 [inline]
lock_acquire+0xcc/0x4f0 kernel/locking/lockdep.c:5594
__raw_spin_lock_irq include/linux/spinlock_api_smp.h:128 [inline]
_raw_spin_lock_irq+0xcf/0x110 kernel/locking/spinlock.c:170
__run_hrtimer kernel/time/hrtimer.c:1692 [inline]
__hrtimer_run_queues+0x662/0xcf0 kernel/time/hrtimer.c:1752
hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1814
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline]
__sysvec_apic_timer_interrupt+0x13b/0x4b0 arch/x86/kernel/apic/apic.c:1114
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:stack_trace_consume_entry+0xed/0x270 kernel/stacktrace.c:93
Code: 00 00 00 00 00 fc ff df 48 8b 1b 45 8d 70 01 41 0f b6 04 17 84 c0 0f 85 2d 01 00 00 45 89 31 4a 8d 1c c3 48 89 d8 48 c1 e8 03 <80> 3c 10 00 74 1a 4d 89 cf 48 89 df 49 89 d6 49 89 f5 e8 dc 41 5c
RSP: 0018:ffffc900033cecf0 EFLAGS: 00000a02
RAX: 1ffff92000679de9 RBX: ffffc900033cef48 RCX: 0000000080000000
RDX: dffffc0000000000 RSI: ffffffff81dba718 RDI: ffffc900033cee2c
RBP: ffffc900033cee28 R08: 0000000000000009 R09: ffffc900033cee30
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff92000679dc5
R13: 1ffff92000679dc5 R14: 000000000000000a R15: 1ffff92000679dc6
arch_stack_walk+0x101/0x140 arch/x86/kernel/stacktrace.c:27
stack_trace_save+0x113/0x1c0 kernel/stacktrace.c:122
save_stack+0xf6/0x1e0 mm/page_owner.c:119
__reset_page_owner+0x52/0x180 mm/page_owner.c:140
reset_page_owner include/linux/page_owner.h:24 [inline]
free_pages_prepare mm/page_alloc.c:1340 [inline]
free_pcp_prepare mm/page_alloc.c:1391 [inline]
free_unref_page_prepare+0xc34/0xcf0 mm/page_alloc.c:3317
free_unref_page_list+0x1f7/0x8e0 mm/page_alloc.c:3433
release_pages+0x1bb9/0x1f40 mm/swap.c:963
__pagevec_release+0x80/0xf0 mm/swap.c:983
pagevec_release include/linux/pagevec.h:81 [inline]
shmem_undo_range+0x67a/0x1b50 mm/shmem.c:964
shmem_truncate_range mm/shmem.c:1063 [inline]
shmem_evict_inode+0x21b/0xa00 mm/shmem.c:1147
evict+0x529/0x930 fs/inode.c:622
__dentry_kill+0x436/0x650 fs/dcache.c:586
dentry_kill+0xbb/0x290
dput+0xd8/0x1a0 fs/dcache.c:893
__fput+0x636/0x8e0 fs/file_table.c:288
task_work_run+0x129/0x1a0 kernel/task_work.c:188
exit_task_work include/linux/task_work.h:33 [inline]
do_exit+0x6a3/0x2480 kernel/exit.c:874
do_group_exit+0x144/0x310 kernel/exit.c:996
get_signal+0xc66/0x14e0 kernel/signal.c:2900
arch_do_signal_or_restart+0xc3/0x1890 arch/x86/kernel/signal.c:867
handle_signal_work kernel/entry/common.c:154 [inline]
exit_to_user_mode_loop+0x97/0x130 kernel/entry/common.c:178
exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214
__syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
syscall_exit_to_user_mode+0x5d/0x240 kernel/entry/common.c:307
do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fe9c994eed9
Code: Unable to access opcode bytes at RIP 0x7fe9c994eeaf.
RSP: 002b:00007fe9c77a4058 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: 0000000000010106 RBX: 00007fe9c9b15080 RCX: 00007fe9c994eed9
RDX: 0000000000010106 RSI: 00000000200000c0 RDI: 0000000000000003
RBP: 00007fe9c99c2cc8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fe9c9b15080 R15: 00007ffd41c3dce8
</TASK>
---
This report is generated by a bot. It may contain errors.
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syzbot
Nov 19, 2025, 4:55:40 AM11/19/25
to syzkaller...@googlegroups.com
syzbot has found a reproducer for the following issue on:
HEAD commit: cc5ec8769306 Linux 5.15.196
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=117a0a12580000
kernel config: https://syzkaller.appspot.com/x/.config?x=e1bb6d24ef2164eb
dashboard link: https://syzkaller.appspot.com/bug?extid=593324eabd9eef11e831
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=109fe692580000
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/ed7568bc5bb4/disk-cc5ec876.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/e343e0aaac77/vmlinux-cc5ec876.xz
kernel image: https://storage.googleapis.com/syzbot-assets/089870f2a980/bzImage-cc5ec876.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+593324...@syzkaller.appspotmail.com
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 0-...!: (1 GPs behind) idle=ed1/1/0x4000000000000002 softirq=19575/19576 fqs=0
(detected by 1, t=10502 jiffies, g=27325, q=160)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 7380 Comm: syz.3.2962 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:debug_lockdep_rcu_enabled+0x0/0x30 kernel/rcu/update.c:279
Code: 5d c0 03 00 75 e8 48 c7 c7 00 1b 0b 8a 48 c7 c6 80 3f 0b 8a e8 71 34 f5 ff 0f 0b eb d1 00 00 cc cc 00 00 cc cc 00 00 cc cc 00 <31> c0 83 3d ab 2a c0 03 00 74 1d 83 3d 22 5d c0 03 00 74 14 65 48
RSP: 0018:ffffc900000070d8 EFLAGS: 00000046
RAX: ffffffff81966a72 RBX: ffff88805bf69dd8 RCX: ffff88801d78d940
RDX: 0000000000000100 RSI: 00000000ffffffe4 RDI: 0000000000000000
RBP: ffffc900000071f8 R08: dffffc0000000000 R09: fffffbfff1ad33a6
R10: fffffbfff1ad33a6 R11: 1ffffffff1ad33a5 R12: 00000000ffffffe4
R13: 1ffff92000000e20 R14: ffffc90000007120 R15: ffffc90000007340
FS: 0000555570c59500(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
rcu_read_unlock include/linux/rcupdate.h:769 [inline]
__perf_event_output kernel/events/core.c:7813 [inline]
perf_event_output_forward+0x19c/0x280 kernel/events/core.c:7822
__perf_event_overflow+0x364/0x530 kernel/events/core.c:9515
perf_swevent_overflow kernel/events/core.c:9591 [inline]
perf_swevent_event+0x4ad/0x530 kernel/events/core.c:9629
perf_tp_event+0x32c/0xb50 kernel/events/core.c:10047
perf_trace_run_bpf_submit+0xf3/0x1c0 kernel/events/core.c:10021
perf_trace_preemptirq_template+0x2be/0x380 include/trace/events/preemptirq.h:14
trace_irq_enable_rcuidle+0x108/0x180 include/trace/events/preemptirq.h:40
trace_hardirqs_on+0x57/0x80 kernel/trace/trace_preemptirq.c:44
asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:713
RIP: 0010:rcu_read_unlock_special+0x84/0x480 kernel/rcu/tree_plugin.h:674
Code: f1 f1 f1 00 f2 f2 f2 4a 89 04 2b 66 42 c7 44 2b 09 f3 f3 42 c6 44 2b 0b f3 65 44 8b 35 ed 11 9e 7e 41 f7 c6 00 00 f0 00 74 45 <48> c7 44 24 20 0e 36 e0 45 4a c7 04 2b 00 00 00 00 66 42 c7 44 2b
RSP: 0018:ffffc90000007780 EFLAGS: 00000206
RAX: 47acb0acde794200 RBX: 1ffff92000000ef4 RCX: 47acb0acde794200
RDX: dffffc0000000000 RSI: ffffffff8a0b1c60 RDI: ffffffff8a59e580
RBP: ffffc90000007860 R08: dffffc0000000000 R09: fffffbfff1ff7c32
R10: fffffbfff1ff7c32 R11: 1ffffffff1ff7c31 R12: ffffffff8c120c00
R13: dffffc0000000000 R14: 0000000000000246 R15: 0000000000000001
__rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:422
rcu_read_unlock include/linux/rcupdate.h:772 [inline]
__ip_queue_xmit+0x1244/0x1c00 net/ipv4/ip_output.c:533
__tcp_transmit_skb+0x1ced/0x31c0 net/ipv4/tcp_output.c:1404
tcp_delack_timer_handler+0x32e/0x730 net/ipv4/tcp_timer.c:314
tcp_delack_timer+0x188/0x2e0 net/ipv4/tcp_timer.c:341
call_timer_fn+0x16c/0x530 kernel/time/timer.c:1451
expire_timers kernel/time/timer.c:1496 [inline]
__run_timers+0x525/0x7c0 kernel/time/timer.c:1767
run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1780
handle_softirqs+0x328/0x820 kernel/softirq.c:576
__do_softirq kernel/softirq.c:610 [inline]
invoke_softirq kernel/softirq.c:450 [inline]
__irq_exit_rcu+0x12f/0x220 kernel/softirq.c:659
irq_exit_rcu+0x5/0x20 kernel/softirq.c:671
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108
Code: e8 21 ae c1 ff 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02 00 00 0f 85 83 00 00 00 41 f7 c7 00 02 00 00 74 01 fb 31 c0 <48> 83 c4 08 5b 41 5c 41 5d 41 5e 41 5f c3 48 8d 80 40 62 03 00 45
RSP: 0018:ffffc90005edfc60 EFLAGS: 00000206
RAX: 47acb0acde794201 RBX: ffff88806f92c758 RCX: 47acb0acde794200
RDX: dffffc0000000000 RSI: ffffffff8a0b1c60 RDI: ffffffff8a59e580
RBP: ffffc90005edfcf8 R08: dffffc0000000000 R09: ffffed1017207662
R10: ffffed1017207662 R11: 1ffff11017207661 R12: ffff8880169e9640
R13: ffff88806f92c758 R14: 000000000003e950 R15: 0000000000000282
kasan_slab_free include/linux/kasan.h:230 [inline]
slab_free_hook mm/slub.c:1710 [inline]
slab_free_freelist_hook+0xea/0x170 mm/slub.c:1736
slab_free mm/slub.c:3504 [inline]
kmem_cache_free+0x8f/0x210 mm/slub.c:3520
__dentry_kill+0x4ef/0x650 fs/dcache.c:600
dentry_kill+0xb8/0x290 fs/dcache.c:-1
dput+0xd8/0x1a0 fs/dcache.c:893
__fput+0x5ee/0x930 fs/file_table.c:319
task_work_run+0x125/0x1a0 kernel/task_work.c:188
tracehook_notify_resume include/linux/tracehook.h:189 [inline]
exit_to_user_mode_loop+0x10f/0x130 kernel/entry/common.c:181
exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214
__syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f3a89f936c9
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:00007ffc13223ba8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 0000000000033d63 RCX: 00007f3a89f936c9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000113223e9f
R10: 0000001b31f20000 R11: 0000000000000246 R12: 00007f3a8a1e9fac
R13: 00007f3a8a1e9fa0 R14: ffffffffffffffff R15: 0000000000000005
</TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g27325 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: Possible timer handling issue on cpu=1 timer-softirq=7609
rcu: rcu_preempt kthread starved for 10502 jiffies! g27325 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=1
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11bb/0x4390 kernel/sched/core.c:6395
schedule+0x11b/0x1e0 kernel/sched/core.c:6478
schedule_timeout+0x15c/0x280 kernel/time/timer.c:1914
rcu_gp_fqs_loop+0x29e/0x11b0 kernel/rcu/tree.c:1972
rcu_gp_kthread+0x98/0x350 kernel/rcu/tree.c:2145
kthread+0x436/0x520 kernel/kthread.c:334
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Call Trace:
<IRQ>
dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
nmi_cpu_backtrace+0x397/0x3d0 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline]
rcu_check_gp_kthread_starvation+0x1cd/0x250 kernel/rcu/tree_stall.h:487
print_other_cpu_stall+0x10c8/0x1220 kernel/rcu/tree_stall.h:592
check_cpu_stall kernel/rcu/tree_stall.h:745 [inline]
rcu_pending kernel/rcu/tree.c:3936 [inline]
rcu_sched_clock_irq+0x831/0x1110 kernel/rcu/tree.c:2619
update_process_times+0x193/0x200 kernel/time/timer.c:1818
tick_sched_handle kernel/time/tick-sched.c:254 [inline]
tick_sched_timer+0x37d/0x560 kernel/time/tick-sched.c:1473
__run_hrtimer kernel/time/hrtimer.c:1685 [inline]
__hrtimer_run_queues+0x4fe/0xc40 kernel/time/hrtimer.c:1749
hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1811
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline]
__sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114
RIP: 0010:arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline]
RIP: 0010:kvm_wait+0x141/0x190 arch/x86/kernel/kvm.c:918
Code: 89 df 48 89 f8 48 c1 e8 03 42 0f b6 04 30 84 c0 75 47 0f b6 1f e8 1f e2 49 00 44 38 e3 75 10 66 90 0f 00 2d 01 69 d4 08 fb f4 <e9> 33 ff ff ff fb e9 2d ff ff ff e8 df 65 75 08 89 f9 80 e1 07 38
RSP: 0018:ffffc90002e5f8c0 EFLAGS: 00000246
RAX: 6c5c2c13f5352200 RBX: 0000000000000003 RCX: 6c5c2c13f5352200
RDX: dffffc0000000000 RSI: ffffffff8a0b1c60 RDI: ffffffff8a59e580
RBP: ffffc90002e5f970 R08: dffffc0000000000 R09: fffffbfff1ff7c32
R10: fffffbfff1ff7c32 R11: 1ffffffff1ff7c31 R12: 0000000000000003
R13: ffff8880b913b154 R14: dffffc0000000000 R15: 1ffff920005cbf18
pv_wait arch/x86/include/asm/paravirt.h:597 [inline]
pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:470 [inline]
__pv_queued_spin_lock_slowpath+0x60f/0x9c0 kernel/locking/qspinlock.c:508
pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:585 [inline]
queued_spin_lock_slowpath+0x43/0x50 arch/x86/include/asm/qspinlock.h:51
queued_spin_lock include/asm-generic/qspinlock.h:85 [inline]
do_raw_spin_lock+0x217/0x280 kernel/locking/spinlock_debug.c:115
spin_lock_bh include/linux/spinlock.h:369 [inline]
lock_sock_nested+0x68/0x100 net/core/sock.c:3259
lock_sock include/net/sock.h:1731 [inline]
tcp_sendmsg+0x1d/0x40 net/ipv4/tcp.c:1456
sock_sendmsg_nosec net/socket.c:706 [inline]
__sock_sendmsg net/socket.c:718 [inline]
sock_write_iter+0x29c/0x380 net/socket.c:1089
call_write_iter include/linux/fs.h:2173 [inline]
new_sync_write fs/read_write.c:507 [inline]
vfs_write+0x712/0xd00 fs/read_write.c:594
ksys_write+0x14d/0x250 fs/read_write.c:647
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fce95638140
Code: 40 00 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 00 80 3d 21 a4 22 00 00 74 17 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 58 c3 0f 1f 80 00 00 00 00 48 83 ec 28 48 89
RSP: 002b:00007ffcb7bd1d08 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00000000057bcf00 RCX: 00007fce95638140
RDX: 00000000000000a0 RSI: 00007fce930e9f60 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000007 R09: 000000000003fde8
R10: aefae6bffd528b33 R11: 0000000000000202 R12: 00000000000000a0
R13: 00005555834f69d0 R14: 00007ffcb7bd21d0 R15: 00007fce930e9f60
</TASK>
---
If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.
HEAD commit: cc5ec8769306 Linux 5.15.196
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=117a0a12580000
kernel config: https://syzkaller.appspot.com/x/.config?x=e1bb6d24ef2164eb
dashboard link: https://syzkaller.appspot.com/bug?extid=593324eabd9eef11e831
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=109fe692580000
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/ed7568bc5bb4/disk-cc5ec876.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/e343e0aaac77/vmlinux-cc5ec876.xz
kernel image: https://storage.googleapis.com/syzbot-assets/089870f2a980/bzImage-cc5ec876.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+593324...@syzkaller.appspotmail.com
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
(detected by 1, t=10502 jiffies, g=27325, q=160)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 7380 Comm: syz.3.2962 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:debug_lockdep_rcu_enabled+0x0/0x30 kernel/rcu/update.c:279
Code: 5d c0 03 00 75 e8 48 c7 c7 00 1b 0b 8a 48 c7 c6 80 3f 0b 8a e8 71 34 f5 ff 0f 0b eb d1 00 00 cc cc 00 00 cc cc 00 00 cc cc 00 <31> c0 83 3d ab 2a c0 03 00 74 1d 83 3d 22 5d c0 03 00 74 14 65 48
RSP: 0018:ffffc900000070d8 EFLAGS: 00000046
RAX: ffffffff81966a72 RBX: ffff88805bf69dd8 RCX: ffff88801d78d940
RDX: 0000000000000100 RSI: 00000000ffffffe4 RDI: 0000000000000000
RBP: ffffc900000071f8 R08: dffffc0000000000 R09: fffffbfff1ad33a6
R10: fffffbfff1ad33a6 R11: 1ffffffff1ad33a5 R12: 00000000ffffffe4
R13: 1ffff92000000e20 R14: ffffc90000007120 R15: ffffc90000007340
FS: 0000555570c59500(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fea07929dac CR3: 000000005a329000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<IRQ>
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
rcu_read_unlock include/linux/rcupdate.h:769 [inline]
__perf_event_output kernel/events/core.c:7813 [inline]
perf_event_output_forward+0x19c/0x280 kernel/events/core.c:7822
__perf_event_overflow+0x364/0x530 kernel/events/core.c:9515
perf_swevent_overflow kernel/events/core.c:9591 [inline]
perf_swevent_event+0x4ad/0x530 kernel/events/core.c:9629
perf_tp_event+0x32c/0xb50 kernel/events/core.c:10047
perf_trace_run_bpf_submit+0xf3/0x1c0 kernel/events/core.c:10021
perf_trace_preemptirq_template+0x2be/0x380 include/trace/events/preemptirq.h:14
trace_irq_enable_rcuidle+0x108/0x180 include/trace/events/preemptirq.h:40
trace_hardirqs_on+0x57/0x80 kernel/trace/trace_preemptirq.c:44
asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:713
RIP: 0010:rcu_read_unlock_special+0x84/0x480 kernel/rcu/tree_plugin.h:674
Code: f1 f1 f1 00 f2 f2 f2 4a 89 04 2b 66 42 c7 44 2b 09 f3 f3 42 c6 44 2b 0b f3 65 44 8b 35 ed 11 9e 7e 41 f7 c6 00 00 f0 00 74 45 <48> c7 44 24 20 0e 36 e0 45 4a c7 04 2b 00 00 00 00 66 42 c7 44 2b
RSP: 0018:ffffc90000007780 EFLAGS: 00000206
RAX: 47acb0acde794200 RBX: 1ffff92000000ef4 RCX: 47acb0acde794200
RDX: dffffc0000000000 RSI: ffffffff8a0b1c60 RDI: ffffffff8a59e580
RBP: ffffc90000007860 R08: dffffc0000000000 R09: fffffbfff1ff7c32
R10: fffffbfff1ff7c32 R11: 1ffffffff1ff7c31 R12: ffffffff8c120c00
R13: dffffc0000000000 R14: 0000000000000246 R15: 0000000000000001
__rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:422
rcu_read_unlock include/linux/rcupdate.h:772 [inline]
__ip_queue_xmit+0x1244/0x1c00 net/ipv4/ip_output.c:533
__tcp_transmit_skb+0x1ced/0x31c0 net/ipv4/tcp_output.c:1404
tcp_delack_timer_handler+0x32e/0x730 net/ipv4/tcp_timer.c:314
tcp_delack_timer+0x188/0x2e0 net/ipv4/tcp_timer.c:341
call_timer_fn+0x16c/0x530 kernel/time/timer.c:1451
expire_timers kernel/time/timer.c:1496 [inline]
__run_timers+0x525/0x7c0 kernel/time/timer.c:1767
run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1780
handle_softirqs+0x328/0x820 kernel/softirq.c:576
__do_softirq kernel/softirq.c:610 [inline]
invoke_softirq kernel/softirq.c:450 [inline]
__irq_exit_rcu+0x12f/0x220 kernel/softirq.c:659
irq_exit_rcu+0x5/0x20 kernel/softirq.c:671
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:kasan_quarantine_put+0x84/0x220 mm/kasan/quarantine.c:234
<TASK>
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
Code: e8 21 ae c1 ff 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02 00 00 0f 85 83 00 00 00 41 f7 c7 00 02 00 00 74 01 fb 31 c0 <48> 83 c4 08 5b 41 5c 41 5d 41 5e 41 5f c3 48 8d 80 40 62 03 00 45
RSP: 0018:ffffc90005edfc60 EFLAGS: 00000206
RAX: 47acb0acde794201 RBX: ffff88806f92c758 RCX: 47acb0acde794200
RDX: dffffc0000000000 RSI: ffffffff8a0b1c60 RDI: ffffffff8a59e580
RBP: ffffc90005edfcf8 R08: dffffc0000000000 R09: ffffed1017207662
R10: ffffed1017207662 R11: 1ffff11017207661 R12: ffff8880169e9640
R13: ffff88806f92c758 R14: 000000000003e950 R15: 0000000000000282
kasan_slab_free include/linux/kasan.h:230 [inline]
slab_free_hook mm/slub.c:1710 [inline]
slab_free_freelist_hook+0xea/0x170 mm/slub.c:1736
slab_free mm/slub.c:3504 [inline]
kmem_cache_free+0x8f/0x210 mm/slub.c:3520
__dentry_kill+0x4ef/0x650 fs/dcache.c:600
dentry_kill+0xb8/0x290 fs/dcache.c:-1
dput+0xd8/0x1a0 fs/dcache.c:893
__fput+0x5ee/0x930 fs/file_table.c:319
task_work_run+0x125/0x1a0 kernel/task_work.c:188
tracehook_notify_resume include/linux/tracehook.h:189 [inline]
exit_to_user_mode_loop+0x10f/0x130 kernel/entry/common.c:181
exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214
__syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f3a89f936c9
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:00007ffc13223ba8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 0000000000033d63 RCX: 00007f3a89f936c9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000113223e9f
R10: 0000001b31f20000 R11: 0000000000000246 R12: 00007f3a8a1e9fac
R13: 00007f3a8a1e9fa0 R14: ffffffffffffffff R15: 0000000000000005
</TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g27325 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: Possible timer handling issue on cpu=1 timer-softirq=7609
rcu: rcu_preempt kthread starved for 10502 jiffies! g27325 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=1
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:27648 pid: 15 ppid: 2 flags:0x00004000
rcu: RCU grace-period kthread stack dump:
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11bb/0x4390 kernel/sched/core.c:6395
schedule+0x11b/0x1e0 kernel/sched/core.c:6478
schedule_timeout+0x15c/0x280 kernel/time/timer.c:1914
rcu_gp_fqs_loop+0x29e/0x11b0 kernel/rcu/tree.c:1972
rcu_gp_kthread+0x98/0x350 kernel/rcu/tree.c:2145
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
</TASK>
rcu: Stack dump where RCU GP kthread last ran:
</TASK>
rcu: Stack dump where RCU GP kthread last ran:
NMI backtrace for cpu 1
CPU: 1 PID: 4198 Comm: syz-executor Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Call Trace:
<IRQ>
dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
nmi_cpu_backtrace+0x397/0x3d0 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline]
rcu_check_gp_kthread_starvation+0x1cd/0x250 kernel/rcu/tree_stall.h:487
print_other_cpu_stall+0x10c8/0x1220 kernel/rcu/tree_stall.h:592
check_cpu_stall kernel/rcu/tree_stall.h:745 [inline]
rcu_pending kernel/rcu/tree.c:3936 [inline]
rcu_sched_clock_irq+0x831/0x1110 kernel/rcu/tree.c:2619
update_process_times+0x193/0x200 kernel/time/timer.c:1818
tick_sched_handle kernel/time/tick-sched.c:254 [inline]
tick_sched_timer+0x37d/0x560 kernel/time/tick-sched.c:1473
__run_hrtimer kernel/time/hrtimer.c:1685 [inline]
__hrtimer_run_queues+0x4fe/0xc40 kernel/time/hrtimer.c:1749
hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1811
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline]
__sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline]
sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline]
RIP: 0010:kvm_wait+0x141/0x190 arch/x86/kernel/kvm.c:918
Code: 89 df 48 89 f8 48 c1 e8 03 42 0f b6 04 30 84 c0 75 47 0f b6 1f e8 1f e2 49 00 44 38 e3 75 10 66 90 0f 00 2d 01 69 d4 08 fb f4 <e9> 33 ff ff ff fb e9 2d ff ff ff e8 df 65 75 08 89 f9 80 e1 07 38
RSP: 0018:ffffc90002e5f8c0 EFLAGS: 00000246
RAX: 6c5c2c13f5352200 RBX: 0000000000000003 RCX: 6c5c2c13f5352200
RDX: dffffc0000000000 RSI: ffffffff8a0b1c60 RDI: ffffffff8a59e580
RBP: ffffc90002e5f970 R08: dffffc0000000000 R09: fffffbfff1ff7c32
R10: fffffbfff1ff7c32 R11: 1ffffffff1ff7c31 R12: 0000000000000003
R13: ffff8880b913b154 R14: dffffc0000000000 R15: 1ffff920005cbf18
pv_wait arch/x86/include/asm/paravirt.h:597 [inline]
pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:470 [inline]
__pv_queued_spin_lock_slowpath+0x60f/0x9c0 kernel/locking/qspinlock.c:508
pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:585 [inline]
queued_spin_lock_slowpath+0x43/0x50 arch/x86/include/asm/qspinlock.h:51
queued_spin_lock include/asm-generic/qspinlock.h:85 [inline]
do_raw_spin_lock+0x217/0x280 kernel/locking/spinlock_debug.c:115
spin_lock_bh include/linux/spinlock.h:369 [inline]
lock_sock_nested+0x68/0x100 net/core/sock.c:3259
lock_sock include/net/sock.h:1731 [inline]
tcp_sendmsg+0x1d/0x40 net/ipv4/tcp.c:1456
sock_sendmsg_nosec net/socket.c:706 [inline]
__sock_sendmsg net/socket.c:718 [inline]
sock_write_iter+0x29c/0x380 net/socket.c:1089
call_write_iter include/linux/fs.h:2173 [inline]
new_sync_write fs/read_write.c:507 [inline]
vfs_write+0x712/0xd00 fs/read_write.c:594
ksys_write+0x14d/0x250 fs/read_write.c:647
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fce95638140
Code: 40 00 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 00 80 3d 21 a4 22 00 00 74 17 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 58 c3 0f 1f 80 00 00 00 00 48 83 ec 28 48 89
RSP: 002b:00007ffcb7bd1d08 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00000000057bcf00 RCX: 00007fce95638140
RDX: 00000000000000a0 RSI: 00007fce930e9f60 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000007 R09: 000000000003fde8
R10: aefae6bffd528b33 R11: 0000000000000202 R12: 00000000000000a0
R13: 00005555834f69d0 R14: 00007ffcb7bd21d0 R15: 00007fce930e9f60
</TASK>
---
If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.
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