rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: (detected by 0, t=10502 jiffies, g=9037, q=20 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4294955844-4294945342), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread starved for 10502 jiffies! g9037 f0x2 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:27528 pid:17 ppid:2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5381 [inline]
__schedule+0x14d2/0x44d0 kernel/sched/core.c:6700
schedule+0xbd/0x170 kernel/sched/core.c:6774
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
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: 5816 Comm: syz-executor297 Not tainted 6.6.101-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:variable_test_bit arch/x86/include/asm/bitops.h:228 [inline]
RIP: 0010:arch_test_bit arch/x86/include/asm/bitops.h:240 [inline]
RIP: 0010:_test_bit include/asm-generic/bitops/instrumented-non-atomic.h:142 [inline]
RIP: 0010:hlock_class kernel/locking/lockdep.c:228 [inline]
RIP: 0010:lookup_chain_cache_add kernel/locking/lockdep.c:3781 [inline]
RIP: 0010:validate_chain kernel/locking/lockdep.c:3837 [inline]
RIP: 0010:__lock_acquire+0x133e/0x7c80 kernel/locking/lockdep.c:5137
Code: c3 81 e3 ff 1f 00 00 c1 e8 03 25 f8 03 00 00 48 8d b8 20 35 da 90 be 08 00 00 00 e8 ac bc 75 00 49 b8 00 00 00 00 00 fc ff df <48> 0f a3 1d 6a 14 73 0f 72 25 48 c7 c0 80 a4 ea 96 48 c1 e8 03 42
RSP: 0018:ffffc90003e27740 EFLAGS: 00000056
RAX: 0000000000000001 RBX: 0000000000000050 RCX: ffffffff816720a4
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff90da3528
RBP: ffffc90003e27988 R08: dffffc0000000000 R09: 1ffffffff21b46a5
R10: dffffc0000000000 R11: fffffbfff21b46a6 R12: c0dbced06914f62e
R13: ffff888025195a00 R14: 000000006914f62e R15: ffff888025196528
FS: 0000555591e9a3c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000006b000 CR3: 00000000789ef000 CR4: 00000000003506e0
Call Trace:
lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754
seqcount_lockdep_reader_access+0xca/0x1c0 include/linux/seqlock.h:102
timekeeping_get_delta kernel/time/timekeeping.c:254 [inline]
timekeeping_get_ns kernel/time/timekeeping.c:388 [inline]
ktime_get+0x7f/0x280 kernel/time/timekeeping.c:848
common_hrtimer_rearm+0x61/0x110 kernel/time/posix-timers.c:248
posixtimer_rearm+0x135/0x340 kernel/time/posix-timers.c:268
dequeue_signal+0x1ba/0x4b0 kernel/signal.c:706
get_signal+0x551/0x1400 kernel/signal.c:2782
arch_do_signal_or_restart+0x96/0x780 arch/x86/kernel/signal.c:310
exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302
do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:87
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f32d79c9899
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 11 19 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffe38de6878 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000000003 RCX: 00007f32d79c9899
RDX: 000020000006b000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 00007f32d7989990 R09: 00007f32d7989990
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f32d7a2733c
R13: 00007f32d7a21106 R14: 00007ffe38de68b0 R15: 0000000000000000