rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5198/2:b..l
rcu: (detected by 0, t=10503 jiffies, g=17361, q=763 ncpus=2)
task:udevd state:R running task stack:25360 pid:5198 tgid:5198 ppid:1 task_flags:0x400140 flags:0x00080800
Call Trace:
context_switch kernel/sched/core.c:5258 [inline]
__schedule+0x150e/0x5070 kernel/sched/core.c:6866
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7193
irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:27 [inline]
RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x11/0x70 kernel/kcov.c:217
Code: 5b e9 73 75 5b 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 65 48 8b 0c 25 08 40 c4 92 <65> 8b 15 b8 47 02 11 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75
RSP: 0018:ffffc90002f17760 EFLAGS: 00000287
RAX: ffffffff8176998b RBX: ffff888079d5b098 RCX: ffff88807ed1db80
RDX: ffff88807ed1db80 RSI: 0000000000000030 RDI: 0000000000000041
RBP: 0000000000000001 R08: ffffffff8fc3d077 R09: 1ffffffff1f87a0e
R10: dffffc0000000000 R11: fffffbfff1f87a0f R12: 0000000000000007
R13: ffffc90002f17888 R14: 0000000000000010 R15: 0000000000000030
__canonical_address arch/x86/include/asm/page.h:79 [inline]
__is_canonical_address arch/x86/include/asm/page.h:84 [inline]
copy_from_kernel_nofault_allowed+0xbb/0x150 arch/x86/mm/maccess.c:36
copy_from_kernel_nofault+0x2b/0x320 mm/maccess.c:36
prepend_copy fs/d_path.c:50 [inline]
prepend+0x13d/0x200 fs/d_path.c:76
prepend_name fs/d_path.c:101 [inline]
__prepend_path fs/d_path.c:133 [inline]
prepend_path+0x339/0x830 fs/d_path.c:172
d_absolute_path+0xa1/0x140 fs/d_path.c:234
tomoyo_get_absolute_path security/tomoyo/realpath.c:101 [inline]
tomoyo_realpath_from_path+0x2c8/0x5d0 security/tomoyo/realpath.c:271
tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
tomoyo_path_perm+0x213/0x4b0 security/tomoyo/file.c:822
security_inode_getattr+0x12f/0x330 security/security.c:1869
vfs_getattr fs/stat.c:259 [inline]
vfs_statx_path fs/stat.c:299 [inline]
vfs_statx+0x18e/0x550 fs/stat.c:356
vfs_fstatat+0x118/0x170 fs/stat.c:375
__do_sys_newfstatat fs/stat.c:542 [inline]
__se_sys_newfstatat fs/stat.c:536 [inline]
__x64_sys_newfstatat+0x116/0x190 fs/stat.c:536
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: 0033:0x7fee1f111b0a
RSP: 002b:00007ffec827dc18 EFLAGS: 00000246 ORIG_RAX: 0000000000000106
RAX: ffffffffffffffda RBX: 00007ffec827e0b0 RCX: 00007fee1f111b0a
RDX: 00007ffec827dc20 RSI: 00007ffec827e0b0 RDI: 00000000ffffff9c
RBP: 000055a3cf8f3910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffec827dcb0
R13: 000055a3a2443100 R14: 000055a3cf902770 R15: 00007ffec827e6d0
rcu: rcu_preempt kthread starved for 10533 jiffies! g17361 f0x0 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:27448 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5258 [inline]
__schedule+0x150e/0x5070 kernel/sched/core.c:6866
__schedule_loop kernel/sched/core.c:6948 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6963
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
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 6315 Comm: syz.1.40 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:26 [inline]
RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:109 [inline]
RIP: 0010:check_preemption_disabled+0x59/0x120 lib/smp_processor_id.c:19
Code: 8b 0d 9b e1 5c 07 48 3b 4c 24 08 0f 85 cc 00 00 00 48 83 c4 10 5b 41 5e 41 5f 5d e9 81 cd 02 00 cc 48 c7 04 24 00 00 00 00 9c <8f> 04 24 f7 04 24 00 02 00 00 74 c8 65 4c 8b 3c 25 08 40 c4 92 41
RSP: 0018:ffffc90003defe60 EFLAGS: 00000046
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000080000000
RDX: 0000000000000000 RSI: ffffffff8be247c0 RDI: ffffffff8be24780
RBP: 0000000000000000 R08: ffff88802fe3bd07 R09: 1ffff11005fc77a0
R10: dffffc0000000000 R11: ffffed1005fc77a1 R12: 0000000000000000
R13: 0000000000000027 R14: ffff88802fe3d6c0 R15: dffffc0000000000
FS: 00007fcda94436c0(0000) GS:ffff888125adc000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000058 CR3: 000000002a29e000 CR4: 00000000003526f0
Call Trace:
fpregs_assert_state_consistent+0xa9/0x150 arch/x86/kernel/fpu/core.c:894
arch_exit_to_user_mode_prepare+0xb/0xd0 arch/x86/include/asm/entry-common.h:63
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:228 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
do_syscall_64+0x17c/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fcda85865e7
Code: 0b e9 68 fe ff ff 48 83 c4 18 48 8d 3d b2 62 d9 00 5b 5d 41 5c 41 5d 41 5e 41 5f e9 23 f8 fb ff 0f 1f 00 b8 27 00 00 00 0f 05 0f 1f 84 00 00 00 00 00 b8 6e 00 00 00 0f 05 c3 0f 1f 84 00 00
RSP: 002b:00007fcda9442b08 EFLAGS: 00000202 ORIG_RAX: 0000000000000027
RAX: 000000000000001f RBX: 00007fcda9442c70 RCX: 00007fcda85865e7
RDX: 00007fcda9442b40 RSI: 00007fcda9442c70 RDI: 0000000000000021
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
R13: 00007fcda87e6038 R14: 00007ffcf16f1cf0 R15: 00007ffcf16f1dd8