rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6349/1:b..l P6265/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=15561, q=453 ncpus=2)
task:udevd state:R running task stack:27112 pid:6265 tgid:6265 ppid:5189 task_flags:0x400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5260 [inline]
__schedule+0x1138/0x5ee0 kernel/sched/core.c:6867
preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:7051
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
_raw_spin_unlock_irqrestore+0x61/0x80 kernel/locking/spinlock.c:194
sock_def_readable+0x15b/0x5d0 net/core/sock.c:3611
unix_dgram_sendmsg+0xcbd/0x1830 net/unix/af_unix.c:2286
sock_sendmsg_nosec net/socket.c:727 [inline]
__sock_sendmsg net/socket.c:742 [inline]
sock_write_iter+0x566/0x610 net/socket.c:1195
new_sync_write fs/read_write.c:593 [inline]
vfs_write+0x7d3/0x11d0 fs/read_write.c:686
ksys_write+0x1f8/0x250 fs/read_write.c:738
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f36796a7407
RSP: 002b:00007ffe590082d0 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f3679eb5880 RCX: 00007f36796a7407
RDX: 0000000000000000 RSI: 00007ffe59008377 RDI: 000000000000000a
RBP: 000000000000000a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00007f3679eb56e8
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
task:syz-executor state:R running task stack:23064 pid:6349 tgid:6349 ppid:6347 task_flags:0x400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5260 [inline]
__schedule+0x1138/0x5ee0 kernel/sched/core.c:6867
preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7194
irqentry_exit+0x1d8/0x8c0 kernel/entry/common.c:216
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:unwind_next_frame+0x1633/0x20b0 arch/x86/kernel/unwind_orc.c:680
Code: 00 0f 84 31 f8 ff ff 4c 89 e7 e8 68 00 bc 00 e9 24 f8 ff ff 48 b8 00 00 00 00 00 fc ff df 48 8b 14 24 48 c1 ea 03 80 3c 02 00 <0f> 85 a8 05 00 00 49 8d 7d 08 49 8b 5d 38 48 b8 00 00 00 00 00 fc
RSP: 0018:ffffc900032e79f8 EFLAGS: 00000246
RAX: dffffc0000000000 RBX: 0000000000000001 RCX: ffffc900032e8000
RDX: 1ffff9200065cf5e RSI: ffffc900032e7b48 RDI: ffffc900032e7af8
RBP: 0000000000000cc0 R08: 0000000000000001 R09: 00000000ffffffff
R10: 0000000000000002 R11: 000000000000637c R12: ffffc900032e7b08
R13: ffffc900032e7ab8 R14: ffffc900032e7b58 R15: ffffc900032e7aec
__unwind_start+0x45f/0x7f0 arch/x86/kernel/unwind_orc.c:773
unwind_start arch/x86/include/asm/unwind.h:64 [inline]
arch_stack_walk+0x73/0x100 arch/x86/kernel/stacktrace.c:24
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
kasan_save_stack+0x33/0x60 mm/kasan/common.c:57
kasan_save_track+0x14/0x30 mm/kasan/common.c:78
unpoison_slab_object mm/kasan/common.c:340 [inline]
__kasan_slab_alloc+0x89/0x90 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+0x25e/0x770 mm/slub.c:5270
getname_flags.part.0+0x4c/0x550 fs/namei.c:146
getname_flags include/linux/audit.h:345 [inline]
getname include/linux/fs.h:2498 [inline]
__do_sys_unlink fs/namei.c:5483 [inline]
__se_sys_unlink fs/namei.c:5481 [inline]
__x64_sys_unlink+0xb0/0x110 fs/namei.c:5481
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fca8c98ecf7
RSP: 002b:00007ffc3adf44d8 EFLAGS: 00000206 ORIG_RAX: 0000000000000057
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fca8c98ecf7
RDX: 00007ffc3adf4500 RSI: 00007ffc3adf4590 RDI: 00007ffc3adf4590
RBP: 00007ffc3adf4590 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000100 R11: 0000000000000206 R12: 00007ffc3adf5620
R13: 00007fca8ca13d7d R14: 00000000000234cd R15: 00007ffc3adf5660
rcu: rcu_preempt kthread starved for 10427 jiffies! g15561 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R running task stack:28328 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5260 [inline]
__schedule+0x1138/0x5ee0 kernel/sched/core.c:6867
preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:7051
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
_raw_spin_unlock_irqrestore+0x61/0x80 kernel/locking/spinlock.c:194
__mod_timer+0x8ed/0xd30 kernel/time/timer.c:1139
add_timer+0x62/0x90 kernel/time/timer.c:1249
schedule_timeout+0x11e/0x290 kernel/time/sleep_timeout.c:98
rcu_gp_fqs_loop+0x1ea/0xaf0 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x26d/0x380 kernel/rcu/tree.c:2285
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x983/0xb10 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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 6612 Comm: syz.1.37 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:vmx_do_nmi_irqoff+0x13/0x20 arch/x86/kvm/vmx/vmenter.S:324
Code: ff ff 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 55 48 89 e5 48 83 e4 f0 6a 18 55 9c 6a 10 e8 7d a6 87 f5 e9 87 84 03 00 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc900040ef978 EFLAGS: 00000082
RAX: 0000000080000200 RBX: ffff8880785d5280 RCX: 0000000000000000
RDX: 0000000080000202 RSI: 0000000000000000 RDI: ffff8880785d5280
RBP: ffffc900040ef978 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880785d722e
R13: 0000000000000001 R14: ffff8880785d7218 R15: 0000000000000000
FS: 00007fa003c3a6c0(0000) GS:ffff8881248f1000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000075a87000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000400
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
vmx_handle_nmi+0xc3/0xd0 arch/x86/kvm/vmx/vmx.c:7371
vmx_vcpu_enter_exit+0x127/0x1b0 arch/x86/kvm/vmx/vmx.c:7408
vmx_vcpu_run+0x963/0x2c10 arch/x86/kvm/vmx/vmx.c:7508
vcpu_enter_guest arch/x86/kvm/x86.c:11365 [inline]
vcpu_run+0x2d0f/0x5a80 arch/x86/kvm/x86.c:11648
kvm_arch_vcpu_ioctl_run+0xfd3/0x1860 arch/x86/kvm/x86.c:11993
kvm_vcpu_ioctl+0x76d/0x16d0 virt/kvm/kvm_main.c:4492
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl fs/ioctl.c:583 [inline]
__x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa002d8f749
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:00007fa003c3a038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fa002fe5fa0 RCX: 00007fa002d8f749
RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000006
RBP: 00007fa002e13f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa002fe6038 R14: 00007fa002fe5fa0 R15: 00007ffebed39f28