rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P11809/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=48225, q=61 ncpus=2)
task:syz-executor state:R running task stack:28744 pid:11809 ppid:6409 flags:0x00004000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5380 [inline]
__schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
preempt_schedule_irq+0xb5/0x140 kernel/sched/core.c:7009
irqentry_exit+0x67/0x70 kernel/entry/common.c:438
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:__seqprop_spinlock_sequence include/linux/seqlock.h:275 [inline]
RIP: 0010:path_init+0x268/0x1200 fs/namei.c:2377
Code: 83 e6 01 31 ff e8 c8 ca 95 ff 89 e8 83 e0 01 48 89 5c 24 20 75 07 e8 07 c7 95 ff eb 40 48 c7 c3 40 47 a1 8c 48 c1 eb 03 f3 90 <42> 0f b6 04 3b 84 c0 75 13 8b 2d 99 7e b1 0a 40 f6 c5 01 74 19 e8
RSP: 0018:ffffc9000bd57b30 EFLAGS: 00000293
RAX: ffffffff81efc8b2 RBX: 1ffffffff19428e8 RCX: ffff88805b495a00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: 0000000000010c37 R08: dffffc0000000000 R09: 1ffffffff21b50a0
R10: dffffc0000000000 R11: fffffbfff21b50a1 R12: 1ffff1100927f444
R13: 0000000000000040 R14: ffffc9000bd57ca0 R15: dffffc0000000000
path_lookupat+0x27/0x440 fs/namei.c:2481
filename_lookup+0x1f4/0x510 fs/namei.c:2520
user_path_at_empty+0x42/0x60 fs/namei.c:2917
user_path_at include/linux/namei.h:57 [inline]
__do_sys_chdir fs/open.c:551 [inline]
__se_sys_chdir+0x95/0x290 fs/open.c:545
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7ff1f2b8e417
RSP: 002b:00007ffee6bd01f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000050
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007ff1f2b8e417
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 00007ffee6bd0250
RBP: 00007ffee6bd023c R08: 0000000000000000 R09: 00007ff1f391d6c0
R10: 000055557cf47500 R11: 0000000000000246 R12: 0000000000000111
R13: 00000000000927c0 R14: 00000000000b2b98 R15: 00007ffee6bd0290
</TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g48225 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: Possible timer handling issue on cpu=1 timer-softirq=45957
rcu: rcu_preempt kthread starved for 10502 jiffies! g48225 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:26920 pid:17 ppid:2 flags:0x00004000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5380 [inline]
__schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
schedule+0xbd/0x170 kernel/sched/core.c:6773
schedule_timeout+0x160/0x280 kernel/time/timer.c:2167
rcu_gp_fqs_loop+0x302/0x1560 kernel/rcu/tree.c:1667
rcu_gp_kthread+0x99/0x380 kernel/rcu/tree.c:1866
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
</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: 11807 Comm: syz-executor Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:arch_atomic_try_cmpxchg arch/x86/include/asm/atomic.h:115 [inline]
RIP: 0010:raw_atomic_try_cmpxchg_acquire include/linux/atomic/atomic-arch-fallback.h:2151 [inline]
RIP: 0010:atomic_try_cmpxchg_acquire include/linux/atomic/atomic-instrumented.h:1296 [inline]
RIP: 0010:queued_spin_lock include/asm-generic/qspinlock.h:111 [inline]
RIP: 0010:do_raw_spin_lock+0x12e/0x2c0 kernel/locking/spinlock_debug.c:115
Code: 00 48 89 df be 04 00 00 00 e8 6e a3 74 00 48 8d 7c 24 40 be 04 00 00 00 e8 5f a3 74 00 8b 44 24 40 b9 01 00 00 00 f0 0f b1 0b <0f> 85 d9 00 00 00 65 8b 1d 51 6e 9b 7e 48 b9 00 00 00 00 00 fc ff
RSP: 0018:ffffc900001f0be0 EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffff8880b8f2b700 RCX: 0000000000000001
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffc900001f0c20
RBP: ffffc900001f0c90 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff5200003e184 R12: ffff8880b8f2b710
R13: ffff8880b8f2b708 R14: 1ffff110171e56e2 R15: 1ffff110171e56e1
FS: 0000555575b45500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f0e3324f764 CR3: 000000002615a000 CR4: 00000000003506e0
Call Trace:
<IRQ>
__raw_spin_lock_irq include/linux/spinlock_api_smp.h:120 [inline]
_raw_spin_lock_irq+0xaf/0xe0 kernel/locking/spinlock.c:170
__run_hrtimer kernel/time/hrtimer.c:1754 [inline]
__hrtimer_run_queues+0x5e3/0xc40 kernel/time/hrtimer.c:1814
hrtimer_interrupt+0x3c9/0x9c0 kernel/time/hrtimer.c:1876
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1077 [inline]
__sysvec_apic_timer_interrupt+0xfb/0x3b0 arch/x86/kernel/apic/apic.c:1094
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1088
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:mnt_get_count+0xf8/0x160 fs/namespace.c:197
Code: 30 3a 7d 8c 4c 89 e0 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 e7 e8 a8 fa e8 ff 4d 03 3c 24 4c 89 f8 48 c1 e8 03 42 0f b6 04 28 <84> c0 75 1a 41 03 2f 41 ff c6 41 83 e6 0f 41 83 fe 07 77 3e e8 2f
RSP: 0018:ffffc9000c2d7d10 EFLAGS: 00000a02
RAX: 0000000000000000 RBX: ffff88802ddb1250 RCX: ffff88802dcd0000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: dffffc0000000000 R09: 1ffffffff21b50a2
R10: dffffc0000000000 R11: fffffbfff21b50a3 R12: ffffffff8c7d3a30
R13: dffffc0000000000 R14: 0000000000000000 R15: ffffe8ffffc3d150
mntput_no_expire+0x2b5/0x860 fs/namespace.c:1307
path_put fs/namei.c:563 [inline]
done_path_create fs/namei.c:3943 [inline]
do_symlinkat+0x210/0x3f0 fs/namei.c:4509
__do_sys_symlinkat fs/namei.c:4523 [inline]
__se_sys_symlinkat fs/namei.c:4520 [inline]
__x64_sys_symlinkat+0x99/0xb0 fs/namei.c:4520
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f0e3318ec47
Code: 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 0a 01 00 00 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:00007ffddc3e8208 EFLAGS: 00000202 ORIG_RAX: 000000000000010a
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f0e3318ec47
RDX: 00007f0e332138ce RSI: 00000000ffffff9c RDI: 00007ffddc3e82a0
RBP: 00007ffddc3e824c R08: 0000000000000017 R09: 00007ffddc3e7f57
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000176
R13: 0000000000000056 R14: 00000000000b20df R15: 00007ffddc3e82a0
</TASK>