rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 1-...!: (10501 ticks this GP) idle=5d5c/1/0x4000000000000000 softirq=0/0 fqs=0 rcuc=10502 jiffies(starved)
rcu: (t=10501 jiffies g=60537 q=135 ncpus=2)
rcu: rcu_preempt kthread timer wakeup didn't happen for 10500 jiffies! g60537 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: Possible timer handling issue on cpu=1 timer-softirq=52049
rcu: rcu_preempt kthread starved for 10501 jiffies! g60537 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:27096 pid:18 tgid:18 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x145f/0x5070 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+0x510/0xa50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 17391 Comm: syz-executor Tainted: G L syzkaller #0 PREEMPT_{RT,(full)}
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:num_possible_cpus include/linux/cpumask.h:1222 [inline]
RIP: 0010:mm_get_cid+0xab/0x130 kernel/sched/sched.h:3759
Code: 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 49 c7 c5 c8 84 01 8d 49 c1 ed 03 bd 00 00 00 80 eb 07 44 89 f0 f7 d8 71 d4 f3 90 <43> 0f b6 44 25 00 84 c0 75 41 44 8b 3d 6c 8b 6f 0b 48 89 df 4c 89
RSP: 0018:ffffc9000516f968 EFLAGS: 00000887
RAX: 0000000080000000 RBX: ffff888038e14bd0 RCX: 1ffff110032e467c
RDX: 0000000000000002 RSI: 0000000000000002 RDI: ffff888038e14bd0
RBP: 0000000080000000 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffed10071c294b R12: dffffc0000000000
R13: 1ffffffff1a03099 R14: 0000000080000000 R15: 0000000000000002
FS: 000055555f0ba500(0000) GS:ffff888126cef000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2f521ff8 CR3: 0000000026ad8000 CR4: 00000000003526f0
Call Trace:
mm_cid_from_cpu kernel/sched/sched.h:3820 [inline]
mm_cid_schedin kernel/sched/sched.h:3870 [inline]
mm_cid_switch_to kernel/sched/sched.h:3886 [inline]
context_switch kernel/sched/core.c:5245 [inline]
__schedule+0x212a/0x5070 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6960
do_nanosleep+0x20f/0x650 kernel/time/hrtimer.c:2116
hrtimer_nanosleep+0x1f7/0x410 kernel/time/hrtimer.c:2163
__do_sys_clock_nanosleep kernel/time/posix-timers.c:1398 [inline]
__se_sys_clock_nanosleep+0x339/0x390 kernel/time/posix-timers.c:1375
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ffaf2272005
Code: Unable to access opcode bytes at 0x7ffaf2271fdb.
RSP: 002b:00007fff1fc7ef30 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6
RAX: ffffffffffffffda RBX: 000000000000004a RCX: 00007ffaf2272005
RDX: 00007fff1fc7ef70 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fff1fc7efdc R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000001388
R13: 00000000000927c0 R14: 000000000017b180 R15: 00007fff1fc7f030
CPU: 1 UID: 0 PID: 18446 Comm: syz.4.3404 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)}
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0xe77/0x1250 kernel/smp.c:877
Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 22 9c 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 5d 97 0b 00 eb 38 f3 90 <42> 0f b6 04 2b 84 c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 41 97
RSP: 0018:ffffc900052bf9e0 EFLAGS: 00000246
RAX: ffffffff81b414ef RBX: 1ffff11017108b21 RCX: 0000000000080000
RDX: ffffc900145fa000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc900052bfb20 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffffbfff1db668f R12: ffff8880b8845908
R13: dffffc0000000000 R14: ffff8880b893c8c0 R15: 0000000000000000
FS: 00007f3c806466c0(0000) GS:ffff888126def000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3c8262b1d0 CR3: 0000000032816000 CR4: 00000000003526f0
Call Trace:
on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1043
on_each_cpu include/linux/smp.h:71 [inline]
smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2711 [inline]
smp_text_poke_batch_finish+0x5f9/0x1130 arch/x86/kernel/alternative.c:2921
arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
static_key_enable_cpuslocked+0x128/0x240 kernel/jump_label.c:210
static_key_enable+0x1a/0x20 kernel/jump_label.c:223
__sched_core_enable kernel/sched/core.c:463 [inline]
sched_core_get+0xaf/0x170 kernel/sched/core.c:487
sched_core_alloc_cookie+0x71/0xa0 kernel/sched/core_sched.c:20
sched_core_share_pid+0x312/0x7b0 kernel/sched/core_sched.c:187
__do_sys_prctl kernel/sys.c:2792 [inline]
__se_sys_prctl+0x223/0x1830 kernel/sys.c:2518
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3c823df749
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f3c80646038 EFLAGS: 00000246 ORIG_RAX: 000000000000009d
RAX: ffffffffffffffda RBX: 00007f3c82635fa0 RCX: 00007f3c823df749
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 000000000000003e
RBP: 00007f3c82463f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f3c82636038 R14: 00007f3c82635fa0 R15: 00007ffeebb9bd78
watchdog: BUG: soft lockup - CPU#1 stuck for 246s! [syz.4.3404:18446]
Modules linked in:
irq event stamp: 51518
hardirqs last enabled at (51517): [] irqentry_exit+0x5dd/0x660 kernel/entry/common.c:219
hardirqs last disabled at (51518): [] sysvec_apic_timer_interrupt+0xe/0xc0 arch/x86/kernel/apic/apic.c:1056
softirqs last enabled at (0): [] rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
softirqs last enabled at (0): [] rcu_read_lock include/linux/rcupdate.h:867 [inline]
softirqs last enabled at (0): [] copy_process+0x915/0x3960 kernel/fork.c:2091
softirqs last disabled at (0): [<0000000000000000>] 0x0
CPU: 1 UID: 0 PID: 18446 Comm: syz.4.3404 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)}
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0xe7c/0x1250 kernel/smp.c:877
Code: 89 ee 83 e6 01 31 ff e8 22 9c 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 5d 97 0b 00 eb 38 f3 90 42 0f b6 04 2b <84> c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 41 97 0b 00 eb e4 44
RSP: 0018:ffffc900052bf9e0 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 1ffff11017108b21 RCX: 0000000000080000
RDX: ffffc900145fa000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc900052bfb20 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffffbfff1db668f R12: ffff8880b8845908
R13: dffffc0000000000 R14: ffff8880b893c8c0 R15: 0000000000000000
FS: 00007f3c806466c0(0000) GS:ffff888126def000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3c8262b1d0 CR3: 0000000032816000 CR4: 00000000003526f0
Call Trace:
on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1043
on_each_cpu include/linux/smp.h:71 [inline]
smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2711 [inline]
smp_text_poke_batch_finish+0x5f9/0x1130 arch/x86/kernel/alternative.c:2921
arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
static_key_enable_cpuslocked+0x128/0x240 kernel/jump_label.c:210
static_key_enable+0x1a/0x20 kernel/jump_label.c:223
__sched_core_enable kernel/sched/core.c:463 [inline]
sched_core_get+0xaf/0x170 kernel/sched/core.c:487
sched_core_alloc_cookie+0x71/0xa0 kernel/sched/core_sched.c:20
sched_core_share_pid+0x312/0x7b0 kernel/sched/core_sched.c:187
__do_sys_prctl kernel/sys.c:2792 [inline]
__se_sys_prctl+0x223/0x1830 kernel/sys.c:2518
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3c823df749
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f3c80646038 EFLAGS: 00000246 ORIG_RAX: 000000000000009d
RAX: ffffffffffffffda RBX: 00007f3c82635fa0 RCX: 00007f3c823df749
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 000000000000003e
RBP: 00007f3c82463f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f3c82636038 R14: 00007f3c82635fa0 R15: 00007ffeebb9bd78
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 17391 Comm: syz-executor Tainted: G L syzkaller #0 PREEMPT_{RT,(full)}
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:_find_first_zero_bit+0x62/0xb0 lib/find_bit.c:149
Code: 49 8b 06 48 83 f8 ff 74 2b 45 31 ed 48 f7 d0 f3 48 0f bc c0 4c 01 e8 48 39 d8 48 0f 43 c3 eb 05 31 db 48 89 d8 5b 41 5c 41 5d <41> 5e 41 5f e9 15 ee 58 06 cc 49 83 c6 08 45 31 ed 4d 89 f7 eb 11
RSP: 0018:ffffc9000516f950 EFLAGS: 00000046
RAX: 0000000000000002 RBX: ffff888038e14bd0 RCX: 1ffff110032e467c
RDX: 0000000000000002 RSI: 0000000000000002 RDI: ffff888038e14bd0
RBP: 0000000080000000 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffed10071c294b R12: dffffc0000000000
R13: 1ffffffff1a03099 R14: ffff888038e14bd0 R15: 0000000000000002
FS: 000055555f0ba500(0000) GS:ffff888126cef000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2f521ff8 CR3: 0000000026ad8000 CR4: 00000000003526f0
Call Trace:
find_first_zero_bit include/linux/find.h:393 [inline]
__mm_get_cid kernel/sched/sched.h:3744 [inline]
mm_get_cid+0xc7/0x130 kernel/sched/sched.h:3759
mm_cid_from_cpu kernel/sched/sched.h:3820 [inline]
mm_cid_schedin kernel/sched/sched.h:3870 [inline]
mm_cid_switch_to kernel/sched/sched.h:3886 [inline]
context_switch kernel/sched/core.c:5245 [inline]
__schedule+0x212a/0x5070 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6960
do_nanosleep+0x20f/0x650 kernel/time/hrtimer.c:2116
hrtimer_nanosleep+0x1f7/0x410 kernel/time/hrtimer.c:2163
__do_sys_clock_nanosleep kernel/time/posix-timers.c:1398 [inline]
__se_sys_clock_nanosleep+0x339/0x390 kernel/time/posix-timers.c:1375
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ffaf2272005
Code: Unable to access opcode bytes at 0x7ffaf2271fdb.
RSP: 002b:00007fff1fc7ef30 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6
RAX: ffffffffffffffda RBX: 000000000000004a RCX: 00007ffaf2272005
RDX: 00007fff1fc7ef70 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fff1fc7efdc R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000001388
R13: 00000000000927c0 R14: 000000000017b180 R15: 00007fff1fc7f030