rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5916/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=7713, q=6 ncpus=2)
task:syz-executor101 state:R running task stack:28200 pid:5916 tgid:5912 ppid:5822 task_flags:0x400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1139/0x6150 kernel/sched/core.c:6863
preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7190
irqentry_exit+0x1d8/0x8c0 kernel/entry/common.c:216
asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:231 [inline]
RIP: 0010:unwind_next_frame+0x2ca/0x20b0 arch/x86/kernel/unwind_orc.c:510
Code: 48 8d 04 7f 48 8d 84 00 dc ae 1a 91 83 c2 01 48 3d d8 a1 dc 91 0f 83 4d 08 00 00 41 89 d0 4f 8d 04 40 4f 8d 84 00 dc ae 1a 91 <49> 81 f8 d8 a1 dc 91 0f 87 31 08 00 00 29 ca 48 8d 3c bd 34 62 99
RSP: 0018:ffffc90002ed72c8 EFLAGS: 00000293
RAX: ffffffff91575730 RBX: 0000000000000001 RCX: 00000000000a1c0e
RDX: 00000000000a1c1a RSI: 00000000000a7c15 RDI: 00000000000a1c0e
RBP: ffffc90002ed7380 R08: ffffffff91575778 R09: 000000006055fedf
R10: 0000000000000002 R11: 0000000000036ad3 R12: ffffc90002ed7388
R13: ffffc90002ed7338 R14: ffffc90002ed736d R15: ffffffff846ad3fa
arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25
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
poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
__kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:415
kasan_kmalloc include/linux/kasan.h:263 [inline]
__do_kmalloc_node mm/slub.c:5657 [inline]
__kmalloc_noprof+0x33d/0x910 mm/slub.c:5669
kmalloc_noprof include/linux/slab.h:961 [inline]
tomoyo_realpath_from_path+0xc2/0x6e0 security/tomoyo/realpath.c:251
tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
tomoyo_check_open_permission+0x2ab/0x3c0 security/tomoyo/file.c:771
tomoyo_file_open+0x6b/0x90 security/tomoyo/tomoyo.c:334
security_file_open+0x84/0x1e0 security/security.c:2636
do_dentry_open+0x597/0x1590 fs/open.c:939
vfs_open+0x82/0x3f0 fs/open.c:1094
do_open fs/namei.c:4628 [inline]
path_openat+0x2078/0x3140 fs/namei.c:4787
do_filp_open+0x20b/0x470 fs/namei.c:4814
do_sys_openat2+0x121/0x290 fs/open.c:1430
do_sys_open fs/open.c:1436 [inline]
__do_sys_openat fs/open.c:1452 [inline]
__se_sys_openat fs/open.c:1447 [inline]
__x64_sys_openat+0x174/0x210 fs/open.c:1447
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: 0033:0x7f0e69035e09
RSP: 002b:00007f0e68fee218 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f0e690c03e8 RCX: 00007f0e69035e09
RDX: 0000000000000002 RSI: 00002000000015c0 RDI: ffffffffffffff9c
RBP: 00007f0e690c03e0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f0e6908d074
R13: 0000200000000698 R14: 0000200000000680 R15: 0000200000000980
rcu: rcu_preempt kthread starved for 10537 jiffies! g7713 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:28120 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1139/0x6150 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:6960
schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99
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: 5917 Comm: vhost-5915 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+0x2d/0xe0 lib/smp_processor_id.c:19
Code: 53 48 83 ec 08 65 8b 1d d5 91 3a 08 65 8b 05 ca 91 3a 08 a9 ff ff ff 7f 74 0f 48 83 c4 08 89 d8 5b 5d 41 5c c3 cc cc cc cc 9c <58> f6 c4 02 74 ea 48 89 fd 65 48 8b 05 8a 91 3a 08 f6 40 2f 04 74
RSP: 0018:ffffc9000442f800 EFLAGS: 00000046
RAX: 0000000080000000 RBX: 0000000000000000 RCX: 0000000000000006
RDX: 0000000000000000 RSI: ffffffff8dace4f3 RDI: ffffffff8bf2b480
RBP: ffffffff820ae781 R08: 0000000000000001 R09: 0000000000000001
R10: ffffffff9088b9d7 R11: ffff88807b37aff0 R12: 0000000000000000
R13: ffffc9000442f980 R14: dffffc0000000000 R15: 0000000000000000
FS: 00007f0e68fee6c0(0000) GS:ffff8881248f5000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000000015c0 CR3: 000000001ef0b000 CR4: 00000000003526f0
Call Trace:
lockdep_hardirqs_on+0x7c/0x110 kernel/locking/lockdep.c:4472
gup_fast mm/gup.c:3169 [inline]
gup_fast_fallback+0x20b1/0x2350 mm/gup.c:3213
pin_user_pages_fast+0xa7/0xf0 mm/gup.c:3326
set_bit_to_user drivers/vhost/vhost.c:2425 [inline]
log_write+0x267/0x320 drivers/vhost/vhost.c:2451
log_used.isra.0+0x170/0x1e0 drivers/vhost/vhost.c:2507
vhost_update_used_flags+0x2ff/0x3d0 drivers/vhost/vhost.c:2582
vhost_enable_notify+0x338/0x6e0 drivers/vhost/vhost.c:3227
vhost_vsock_handle_tx_kick+0x900/0xdb0 drivers/vhost/vsock.c:519
vhost_run_work_list+0x18b/0x230 drivers/vhost/vhost.c:454
vhost_task_fn+0x165/0x460 kernel/vhost_task.c:49
ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.145 msecs