rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5197/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=24917, q=916 ncpus=2)
task:udevd state:R running task stack:22712 pid:5197 tgid:5197 ppid:1 task_flags:0x400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x14bc/0x5000 kernel/sched/core.c:6863
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7190
irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:__orc_find arch/x86/kernel/unwind_orc.c:99 [inline]
RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:227 [inline]
RIP: 0010:unwind_next_frame+0x1334/0x2390 arch/x86/kernel/unwind_orc.c:494
Code: 0f b6 04 08 84 c0 75 27 49 63 07 4c 01 f8 49 8d 4f 04 4c 39 e0 48 0f 46 e9 49 8d 47 fc 48 0f 47 d8 4d 0f 46 ef 48 39 dd 76 a2 7b ef ff ff 44 89 f9 80 e1 07 80 c1 03 38 c1 7c cc 4c 89 ff 48
RSP: 0018:ffffc9000f1ff3f8 EFLAGS: 00000202
RAX: ffffffff8fa3b034 RBX: ffffffff8fa3b034 RCX: ffffffff8fa3b03c
RDX: ffffffff8fa3b034 RSI: ffffffff90240250 RDI: ffffffff8bc07a80
RBP: ffffffff8fa3b038 R08: 0000000000000006 R09: ffffffff8df419e0
R10: ffffc9000f1ff518 R11: ffffffff81ada290 R12: ffffffff8239e10d
R13: ffffffff8fa3b034 R14: ffffc9000f1ff4c8 R15: ffffffff8fa3b038
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
unpoison_slab_object mm/kasan/common.c:340 [inline]
__kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366
kasan_slab_alloc include/linux/kasan.h:253 [inline]
slab_post_alloc_hook mm/slub.c:4953 [inline]
slab_alloc_node mm/slub.c:5263 [inline]
kmem_cache_alloc_noprof+0x37d/0x710 mm/slub.c:5270
lsm_file_alloc security/security.c:169 [inline]
security_file_alloc+0x34/0x330 security/security.c:2380
init_file+0x93/0x2f0 fs/file_table.c:159
alloc_empty_file+0x6e/0x1d0 fs/file_table.c:241
path_openat+0x108/0x3dd0 fs/namei.c:4773
do_filp_open+0x1fa/0x410 fs/namei.c:4814
do_sys_openat2+0x121/0x200 fs/open.c:1430
do_sys_open fs/open.c:1436 [inline]
__do_sys_openat fs/open.c:1452 [inline]
__se_sys_openat fs/open.c:1447 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1447
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f074d915c3a
RSP: 002b:00007ffe136c3fd8 EFLAGS: 00000206 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000562d2364b810 RCX: 00007f074d915c3a
RDX: 0000000000090800 RSI: 0000562d23619940 RDI: 00000000ffffff9c
RBP: 0000562d23619940 R08: 0000000000000000 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000206 R12: 0000562d235f87b0
R13: 00000000000000ff R14: 0000562d21f46be0 R15: 00007ffe136c4260
rcu: rcu_preempt kthread starved for 10532 jiffies! g24917 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R running task stack:27168 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x14bc/0x5000 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6960
schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 7524 Comm: vhost-7520 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:lock_acquire+0x112/0x340 kernel/locking/lockdep.c:5868
Code: 4c 89 7c 24 08 41 f7 c7 00 02 00 00 41 0f 94 c1 4c 89 ef 89 de 8b 54 24 04 44 89 e1 45 89 f0 6a 00 6a 00 6a 00 55 ff 74 24 30 c9 02 00 00 48 83 c4 28 48 c7 c7 3e 7b 97 8d e8 59 f6 bc 09 b8
RSP: 0018:ffffc9000edb7b80 EFLAGS: 00000046
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8880299f9620
RBP: ffffffff81c1c8ce R08: 0000000000000001 R09: 0000000000000001
R10: dffffc0000000000 R11: fffffbfff1f0406f R12: 0000000000000000
R13: ffff8880299f9620 R14: 0000000000000001 R15: 0000000000000046
FS: 00007f794c1556c0(0000) GS:ffff888125f37000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000002 CR3: 0000000076ed2000 CR4: 00000000003526f0
Call Trace:
__raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
_raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
spin_lock include/linux/spinlock.h:351 [inline]
kcov_remote_stop+0x2ae/0x6f0 kernel/kcov.c:1049
vhost_run_work_list+0x153/0x1e0 drivers/vhost/vhost.c:455
vhost_task_fn+0x27c/0x430 kernel/vhost_task.c:49
ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246