rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 0-...!: (0 ticks this GP) idle=a41/1/0x4000000000000002 softirq=61281/61281 fqs=0
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P25150
(detected by 1, t=10506 jiffies, g=87245, q=640)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 25150 Comm: syz.3.5021 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
RIP: 0010:asm_sysvec_irq_work+0x0/0x20 arch/x86/include/asm/idtentry.h:707
Code: e9 a5 03 00 00 90 90 90 90 90 0f 01 ca fc 6a ff e8 a5 02 00 00 48 89 c4 48 89 e7 e8 8a ea e1 ff e9 85 03 00 00 90 90 90 90 90 <0f> 01 ca fc 6a ff e8 85 02 00 00 48 89 c4 48 89 e7 e8 5a ef e1 ff
RSP: 0018:ffffc90003bb7cb8 EFLAGS: 00000006
RAX: 0e2dc4cda61dd400 RBX: 1ffff92000776fa0 RCX: 0e2dc4cda61dd400
RDX: dffffc0000000000 RSI: ffffffff8a2b2b60 RDI: ffffffff8a7a4b40
RBP: ffffc90003bb7da8 R08: ffffffff910150cf R09: 1ffffffff2202a19
R10: dffffc0000000000 R11: fffffbfff2202a1a R12: 0000000000000000
R13: dffffc0000000000 R14: 0000000000000246 R15: ffffffff8d1234e0
FS: 000055556dadc500(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b30422ff8 CR3: 0000000042c2a000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
RIP: 0010:rcu_read_unlock_special+0x7f/0x4a0 kernel/rcu/tree_plugin.h:674
Code: eb 03 48 b8 f1 f1 f1 f1 f8 f2 f2 f2 4a 89 04 2b 42 c7 44 2b 08 f8 f3 f3 f3 65 44 8b 35 82 fc 9c 7e 41 f7 c6 00 00 f0 00 74 40 <48> c7 44 24 20 0e 36 e0 45 4a c7 04 2b 00 00 00 00 42 c7 44 2b 08
RSP: 0018:ffffc90003bb7ce0 EFLAGS: 00000206
__rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:422
rcu_read_unlock+0x85/0x90 include/linux/rcupdate.h:772
dput+0xc0/0x1a0 fs/dcache.c:886
__fput+0x5a5/0x8c0 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:184
exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:217
__syscall_exit_to_user_mode_work kernel/entry/common.c:299 [inline]
syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:310
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fa7f9b90559
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffc0b1ba378 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007fa7f9e19da0 RCX: 00007fa7f9b90559
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007fa7f9e19da0 R08: 00007fa7f9e18038 R09: 0000000000000000
R10: 00000000003fe9e8 R11: 0000000000000246 R12: 00000000000a35c7
R13: 00007fa7f9e1809c R14: 00000000000a3318 R15: 00007ffc0b1ba480
task:syz.3.5021 state:R running task stack:26576 pid:25150 ppid: 18879 flags:0x0000400c
Call Trace:
rcu: rcu_preempt kthread timer wakeup didn't happen for 10505 jiffies! g87245 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: Possible timer handling issue on cpu=0 timer-softirq=48473
rcu: rcu_preempt kthread starved for 10506 jiffies! g87245 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:27632 pid: 15 ppid: 2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11c3/0x4350 kernel/sched/core.c:6395
schedule+0x11b/0x1e0 kernel/sched/core.c:6478
schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2117
rcu_gp_fqs_loop+0x2be/0x11f0 kernel/rcu/tree.c:1972
rcu_gp_kthread+0x9a/0x370 kernel/rcu/tree.c:2145
kthread+0x42e/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
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: 25150 Comm: syz.3.5021 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
RIP: 0010:check_kcov_mode kernel/kcov.c:182 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x32/0x60 kernel/kcov.c:205
Code: 54 4c 89 7e 65 8b 15 55 4c 89 7e 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 34 16 00 00 00 74 2c 8b 91 10 16 00 00 <83> fa 02 75 21 48 8b 91 18 16 00 00 48 8b 32 48 8d 7e 01 8b 89 14
RSP: 0018:ffffc90003bb77e0 EFLAGS: 00000046
RAX: ffffffff8198b1af RBX: 0000000000000000 RCX: ffff88802d0b5940
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000002
RBP: ffffc90003bb78c0 R08: ffff88802d0b5947 R09: 1ffff11005a16b28
R10: dffffc0000000000 R11: ffffed1005a16b29 R12: 0000000000000001
R13: ffff8880b8e35120 R14: 1ffff110051b3577 R15: 0000000000000007
FS: 000055556dadc500(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b30422ff8 CR3: 0000000042c2a000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
perf_swevent_event+0x33f/0x540 kernel/events/core.c:9636
perf_tp_event+0x324/0xbe0 kernel/events/core.c:10057
perf_trace_run_bpf_submit+0xf3/0x1c0 kernel/events/core.c:10031
perf_trace_preemptirq_template+0x2aa/0x360 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+0x7f/0x4a0 kernel/rcu/tree_plugin.h:674
Code: eb 03 48 b8 f1 f1 f1 f1 f8 f2 f2 f2 4a 89 04 2b 42 c7 44 2b 08 f8 f3 f3 f3 65 44 8b 35 82 fc 9c 7e 41 f7 c6 00 00 f0 00 74 40 <48> c7 44 24 20 0e 36 e0 45 4a c7 04 2b 00 00 00 00 42 c7 44 2b 08
RSP: 0018:ffffc90003bb7ce0 EFLAGS: 00000206
RAX: 0e2dc4cda61dd400 RBX: 1ffff92000776fa0 RCX: 0e2dc4cda61dd400
RDX: dffffc0000000000 RSI: ffffffff8a2b2b60 RDI: ffffffff8a7a4b40
RBP: ffffc90003bb7da8 R08: ffffffff910150cf R09: 1ffffffff2202a19
R10: dffffc0000000000 R11: fffffbfff2202a1a R12: 0000000000000000
R13: dffffc0000000000 R14: 0000000000000246 R15: ffffffff8d1234e0
__rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:422
rcu_read_unlock+0x85/0x90 include/linux/rcupdate.h:772
dput+0xc0/0x1a0 fs/dcache.c:886
__fput+0x5a5/0x8c0 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:184
exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:217
__syscall_exit_to_user_mode_work kernel/entry/common.c:299 [inline]
syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:310
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fa7f9b90559
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffc0b1ba378 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007fa7f9e19da0 RCX: 00007fa7f9b90559
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007fa7f9e19da0 R08: 00007fa7f9e18038 R09: 0000000000000000
R10: 00000000003fe9e8 R11: 0000000000000246 R12: 00000000000a35c7
R13: 00007fa7f9e1809c R14: 00000000000a3318 R15: 00007ffc0b1ba480