rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 0-...!: (10500 ticks this GP) idle=ca9c/1/0x4000000000000000 softirq=0/0 fqs=0 rcuc=10510 jiffies(starved)
rcu: (t=10500 jiffies g=86117 q=474 ncpus=2)
rcu: rcu_preempt kthread timer wakeup didn't happen for 10499 jiffies! g86117 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: Possible timer handling issue on cpu=0 timer-softirq=42529
rcu: rcu_preempt kthread starved for 10500 jiffies! g86117 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:27168 pid:18 tgid:18 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1480/0x50a0 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
CPU: 0 UID: 0 PID: 10408 Comm: dhcpcd-run-hook Not tainted syzkaller #0 PREEMPT_{RT,(full)}
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+0xec1/0x12b0 kernel/smp.c:877
Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 c8 9d 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 03 99 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 e7 98
RSP: 0018:ffffc90004007580 EFLAGS: 00000293
RAX: ffffffff81b4c9a9 RBX: 1ffff1101712854d RCX: ffff888030738000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90004007700 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffffbfff1db662f R12: ffff8880b8942a68
R13: dffffc0000000000 R14: ffff8880b883c8c0 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff888126d03000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f515a7277d0 CR3: 000000000d3a8000 CR4: 00000000003526f0
Call Trace:
on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1043
__flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline]
flush_tlb_multi arch/x86/mm/tlb.c:1382 [inline]
flush_tlb_mm_range+0x6b1/0x1280 arch/x86/mm/tlb.c:1472
tlb_flush arch/x86/include/asm/tlb.h:23 [inline]
tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:490 [inline]
tlb_flush_mmu+0x1a7/0x680 mm/mmu_gather.c:403
tlb_finish_mmu+0xc3/0x1d0 mm/mmu_gather.c:497
free_ldt_pgtables+0x17b/0x320 arch/x86/kernel/ldt.c:411
arch_exit_mmap arch/x86/include/asm/mmu_context.h:234 [inline]
exit_mmap+0x174/0xb10 mm/mmap.c:1263
__mmput+0xcb/0x3d0 kernel/fork.c:1173
exit_mm+0x1da/0x2c0 kernel/exit.c:581
do_exit+0x658/0x2310 kernel/exit.c:959
do_group_exit+0x21c/0x2d0 kernel/exit.c:1112
__do_sys_exit_group kernel/exit.c:1123 [inline]
__se_sys_exit_group kernel/exit.c:1121 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1121
x64_sys_call+0x2210/0x2210 arch/x86/include/generated/asm/syscalls_64.h:232
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: 0033:0x7f515a6256c5
Code: Unable to access opcode bytes at 0x7f515a62569b.
RSP: 002b:00007ffcea2cb9c8 EFLAGS: 00000202 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007ffcea2cbc04 RCX: 00007f515a6256c5
RDX: 00000000000000e7 RSI: ffffffffffffff88 RDI: 0000000000000000
RBP: 0000000000000003 R08: 00007ffcea2cbac0 R09: 0000000000000002
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
R13: 00007ffcea2cbd00 R14: 00007f515a835000 R15: 0000557985ba7d98
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 9886 Comm: syz-executor Not tainted syzkaller #0 PREEMPT_{RT,(full)}
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 e9 51 e0 44 09 cc 49 c7 c5 c8 b4 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 0c 4d 6f 0b 48 89 df 4c 89
RSP: 0018:ffffc90003ad7948 EFLAGS: 00000887
RAX: 0000000080000000 RBX: ffff88803cef3250 RCX: 1ffff11004e5d2b4
RDX: 0000000000000002 RSI: 0000000000000002 RDI: ffff88803cef3250
RBP: 0000000080000000 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffed10079de61b R12: dffffc0000000000
R13: 1ffffffff1a03699 R14: 0000000080000000 R15: 0000000000000002
FS: 000055555e504500(0000) GS:ffff888126e03000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6206d24e9c CR3: 0000000073890000 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+0x2153/0x50a0 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+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f35e0f22005
Code: Unable to access opcode bytes at 0x7f35e0f21fdb.
RSP: 002b:00007ffd2d08be10 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6
RAX: ffffffffffffffda RBX: 000000000000000f RCX: 00007f35e0f22005
RDX: 00007ffd2d08be50 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ffd2d08bebc R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000001388
R13: 00000000000927c0 R14: 00000000000a8956 R15: 00007ffd2d08bf10
watchdog: BUG: soft lockup - CPU#0 stuck for 246s! [dhcpcd-run-hook:10408]
Modules linked in:
irq event stamp: 55982
hardirqs last enabled at (55981): [] irqentry_exit+0x5dd/0x660 kernel/entry/common.c:219
hardirqs last disabled at (55982): [] 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: 0 UID: 0 PID: 10408 Comm: dhcpcd-run-hook Not tainted syzkaller #0 PREEMPT_{RT,(full)}
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+0xec1/0x12b0 kernel/smp.c:877
Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 c8 9d 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 03 99 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 e7 98
RSP: 0018:ffffc90004007580 EFLAGS: 00000293
RAX: ffffffff81b4c9a9 RBX: 1ffff1101712854d RCX: ffff888030738000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90004007700 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffffbfff1db662f R12: ffff8880b8942a68
R13: dffffc0000000000 R14: ffff8880b883c8c0 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff888126d03000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f515a7277d0 CR3: 000000000d3a8000 CR4: 00000000003526f0
Call Trace:
on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1043
__flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline]
flush_tlb_multi arch/x86/mm/tlb.c:1382 [inline]
flush_tlb_mm_range+0x6b1/0x1280 arch/x86/mm/tlb.c:1472
tlb_flush arch/x86/include/asm/tlb.h:23 [inline]
tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:490 [inline]
tlb_flush_mmu+0x1a7/0x680 mm/mmu_gather.c:403
tlb_finish_mmu+0xc3/0x1d0 mm/mmu_gather.c:497
free_ldt_pgtables+0x17b/0x320 arch/x86/kernel/ldt.c:411
arch_exit_mmap arch/x86/include/asm/mmu_context.h:234 [inline]
exit_mmap+0x174/0xb10 mm/mmap.c:1263
__mmput+0xcb/0x3d0 kernel/fork.c:1173
exit_mm+0x1da/0x2c0 kernel/exit.c:581
do_exit+0x658/0x2310 kernel/exit.c:959
do_group_exit+0x21c/0x2d0 kernel/exit.c:1112
__do_sys_exit_group kernel/exit.c:1123 [inline]
__se_sys_exit_group kernel/exit.c:1121 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1121
x64_sys_call+0x2210/0x2210 arch/x86/include/generated/asm/syscalls_64.h:232
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: 0033:0x7f515a6256c5
Code: Unable to access opcode bytes at 0x7f515a62569b.
RSP: 002b:00007ffcea2cb9c8 EFLAGS: 00000202 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007ffcea2cbc04 RCX: 00007f515a6256c5
RDX: 00000000000000e7 RSI: ffffffffffffff88 RDI: 0000000000000000
RBP: 0000000000000003 R08: 00007ffcea2cbac0 R09: 0000000000000002
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
R13: 00007ffcea2cbd00 R14: 00007f515a835000 R15: 0000557985ba7d98
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 9886 Comm: syz-executor Not tainted syzkaller #0 PREEMPT_{RT,(full)}
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 e9 51 e0 44 09 cc 49 c7 c5 c8 b4 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 0c 4d 6f 0b 48 89 df 4c 89
RSP: 0018:ffffc90003ad7948 EFLAGS: 00000887
RAX: 0000000080000000 RBX: ffff88803cef3250 RCX: 1ffff11004e5d2b4
RDX: 0000000000000002 RSI: 0000000000000002 RDI: ffff88803cef3250
RBP: 0000000080000000 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffed10079de61b R12: dffffc0000000000
R13: 1ffffffff1a03699 R14: 0000000080000000 R15: 0000000000000002
FS: 000055555e504500(0000) GS:ffff888126e03000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6206d24e9c CR3: 0000000073890000 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+0x2153/0x50a0 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+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f35e0f22005
Code: Unable to access opcode bytes at 0x7f35e0f21fdb.
RSP: 002b:00007ffd2d08be10 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6
RAX: ffffffffffffffda RBX: 000000000000000f RCX: 00007f35e0f22005
RDX: 00007ffd2d08be50 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ffd2d08bebc R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000001388
R13: 00000000000927c0 R14: 00000000000a8956 R15: 00007ffd2d08bf10