rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P4391
(detected by 1, t=10502 jiffies, g=8553, q=1061)
task:syz.2.28 state:R running task stack:27472 pid: 4391 ppid: 4318 flags:0x0000400c
Call Trace:
rcu: rcu_preempt kthread timer wakeup didn't happen for 10495 jiffies! g8553 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: Possible timer handling issue on cpu=0 timer-softirq=3125
rcu: rcu_preempt kthread starved for 10496 jiffies! g8553 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:27456 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: 4391 Comm: syz.2.28 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:asm_exc_page_fault+0x0/0x30 arch/x86/include/asm/idtentry.h:605
Code: 74 24 28 ff 74 24 28 ff 74 24 28 ff 74 24 28 e8 a6 05 00 00 48 89 c4 48 89 e7 e8 4b e3 df ff e9 86 06 00 00 90 90 90 90 90 90 <0f> 01 ca fc e8 87 05 00 00 48 89 c4 48 89 e7 48 8b 74 24 78 48 c7
RSP: 0018:ffffc90003b2f410 EFLAGS: 00040802
RAX: 0000000000014d3a RBX: dffffc0000000000 RCX: ffff8880588a8000
RDX: 1ffff92000765ea6 RSI: 0000000000014d3a RDI: 00007fffffffeff0
RBP: 0000000000000000 R08: ffffffff8d8b0def R09: 1ffffffff1b161bd
R10: dffffc0000000000 R11: fffffbfff1b161be R12: ffff8880588a9788
R13: 00000000ffffffff R14: 0000000000014d3a R15: 000000000000007f
FS: 000055557d3e1500(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000014d3a CR3: 0000000022e57000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
RIP: 0010:__get_user_nocheck_8+0x6/0x13 arch/x86/lib/getuser.S:155
Code: 01 ca c3 90 0f 01 cb 0f ae e8 0f b7 10 31 c0 0f 01 ca c3 90 0f 01 cb 0f ae e8 8b 10 31 c0 0f 01 ca c3 90 90 0f 01 cb 0f ae e8 <48> 8b 10 31 c0 0f 01 ca c3 90 0f 01 ca 31 d2 48 c7 c0 f2 ff ff ff
RSP: 0018:ffffc90003b2f440 EFLAGS: 00050802
perf_callchain_user+0x423/0xf80 arch/x86/events/core.c:2900
get_perf_callchain+0x33d/0x460 kernel/events/callchain.c:221
perf_callchain kernel/events/core.c:7606 [inline]
perf_prepare_sample+0x352/0x1cb0 kernel/events/core.c:7633
__perf_event_output kernel/events/core.c:7802 [inline]
perf_event_output_forward+0x185/0x2e0 kernel/events/core.c:7822
__perf_event_overflow+0x35f/0x550 kernel/events/core.c:9515
perf_tp_event+0x324/0xbe0 kernel/events/core.c:10047
perf_trace_run_bpf_submit+0xf3/0x1c0 kernel/events/core.c:10021
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 02 20 9d 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:ffffc90003b2fce0 EFLAGS: 00000206
RAX: ebc7f5a928751100 RBX: 1ffff92000765fa0 RCX: ebc7f5a928751100
RDX: dffffc0000000000 RSI: ffffffff8a2b2be0 RDI: ffffffff8a7a4200
RBP: ffffc90003b2fda8 R08: ffffffff901ee0cf R09: 1ffffffff203dc19
R10: dffffc0000000000 R11: fffffbfff203dc1a R12: 0000000000000000
R13: dffffc0000000000 R14: 0000000000000246 R15: ffffffff8c3234a0
__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: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: 0033:0x7fc84c1e70d9
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:00007ffca318b898 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007ffca318b980 RCX: 00007fc84c1e70d9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 0000000000014d3a R08: 0000000000000001 R09: 0000000000000000
R10: 0000001b31620000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc84c46efac R14: 00007fc84c46efa8 R15: 00007fc84c46efa0