rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P10789/1:b..l P5220/1:b..l P5854/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=36661, q=1091 ncpus=2)
task:syz-executor state:R running task stack:24024 pid:5854 tgid:5854 ppid:5841 task_flags:0x400140 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6961
preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:7145
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
__raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline]
_raw_spin_unlock+0x3e/0x50 kernel/locking/spinlock.c:186
spin_unlock include/linux/spinlock.h:391 [inline]
copy_pte_range mm/memory.c:1201 [inline]
copy_pmd_range mm/memory.c:1261 [inline]
copy_pud_range mm/memory.c:1298 [inline]
copy_p4d_range mm/memory.c:1322 [inline]
copy_page_range+0x1f7d/0x5c80 mm/memory.c:1410
dup_mmap+0xe88/0x21d0 mm/mmap.c:1834
dup_mm kernel/fork.c:1485 [inline]
copy_mm kernel/fork.c:1537 [inline]
copy_process+0x4081/0x7690 kernel/fork.c:2175
kernel_clone+0xfc/0x930 kernel/fork.c:2605
__do_sys_clone+0xce/0x120 kernel/fork.c:2748
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa8baf85453
RSP: 002b:00007ffd9cfe08f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fa8baf85453
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001
R10: 000055557fe607d0 R11: 0000000000000246 R12: 0000000000000000
R13: 00000000000927c0 R14: 000000000007ac8b R15: 00007ffd9cfe0a90
task:udevd state:R running task stack:24712 pid:5220 tgid:5220 ppid:1 task_flags:0x400140 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6961
preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7288
irqentry_exit+0x36/0x90 kernel/entry/common.c:197
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:unwind_next_frame+0x642/0x20a0 arch/x86/kernel/unwind_orc.c:517
Code: fc ff df 48 c1 e8 03 0f b6 34 10 48 8d 41 01 48 89 c7 48 c1 ef 03 0f b6 14 17 48 89 cf 83 e7 07 40 38 fe 40 0f 9e c7 40 84 f6 <40> 0f 95 c6 40 84 f7 0f 85 a1 16 00 00 83 e0 07 38 c2 40 0f 9e c6
RSP: 0018:ffffc90003b0f8b8 EFLAGS: 00000246
RAX: ffffffff913ac61f RBX: 0000000000000001 RCX: ffffffff913ac61e
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001
RBP: ffffc90003b0f970 R08: ffffffff913ac622 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: ffffc90003b0f978
R13: ffffc90003b0f928 R14: 0000000000000005 R15: ffffc90003b0ff58
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:47
kasan_save_track+0x14/0x30 mm/kasan/common.c:68
unpoison_slab_object mm/kasan/common.c:330 [inline]
__kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:356
kasan_slab_alloc include/linux/kasan.h:250 [inline]
slab_post_alloc_hook mm/slub.c:4191 [inline]
slab_alloc_node mm/slub.c:4240 [inline]
kmem_cache_alloc_noprof+0x1cb/0x3b0 mm/slub.c:4247
getname_flags.part.0+0x4c/0x550 fs/namei.c:146
getname_flags+0x93/0xf0 include/linux/audit.h:322
getname include/linux/fs.h:2918 [inline]
getname_maybe_null include/linux/fs.h:2925 [inline]
getname_maybe_null include/linux/fs.h:2922 [inline]
vfs_fstatat+0xe1/0xf0 fs/stat.c:370
__do_sys_newfstatat+0x97/0x120 fs/stat.c:542
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f487b311b0a
RSP: 002b:00007ffd3b6d80c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000106
RAX: ffffffffffffffda RBX: 00007ffd3b6d8560 RCX: 00007f487b311b0a
RDX: 00007ffd3b6d80d0 RSI: 00007ffd3b6d8560 RDI: 00000000ffffff9c
RBP: 000055e85669f2c0 R08: 0000000000000000 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffd3b6d8160
R13: 0000000000000100 R14: 000055e83207cbe0 R15: 00007ffd3b6d8be0
task:syz.0.1279 state:R running task stack:26264 pid:10789 tgid:10789 ppid:5844 task_flags:0x40004c flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6961
preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:7145
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
__raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline]
_raw_spin_unlock+0x3e/0x50 kernel/locking/spinlock.c:186
spin_unlock include/linux/spinlock.h:391 [inline]
zap_pte_range mm/memory.c:1756 [inline]
zap_pmd_range mm/memory.c:1818 [inline]
zap_pud_range mm/memory.c:1847 [inline]
zap_p4d_range mm/memory.c:1868 [inline]
unmap_page_range+0xf77/0x42c0 mm/memory.c:1889
unmap_single_vma.constprop.0+0x153/0x240 mm/memory.c:1932
unmap_vmas+0x218/0x470 mm/memory.c:1976
exit_mmap+0x1b9/0xb90 mm/mmap.c:1280
__mmput+0x12a/0x410 kernel/fork.c:1130
mmput+0x62/0x70 kernel/fork.c:1152
exit_mm kernel/exit.c:582 [inline]
do_exit+0x7c7/0x2bf0 kernel/exit.c:949
do_group_exit+0xd3/0x2a0 kernel/exit.c:1102
__do_sys_exit_group kernel/exit.c:1113 [inline]
__se_sys_exit_group kernel/exit.c:1111 [inline]
__x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1111
x64_sys_call+0x14fa/0x1720 arch/x86/include/generated/asm/syscalls_64.h:232
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff00a98ebe9
RSP: 002b:00007ffec64612b8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007ff00a98ebe9
RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ffec646131c R08: 00000013c64613af R09: 00000000000927c0
R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000104
R13: 00000000000927c0 R14: 000000000007aa0e R15: 00007ffec6461370
rcu: rcu_preempt kthread starved for 9714 jiffies! g36661 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:27928 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:7058
schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1ea/0xb00 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x270/0x380 kernel/rcu/tree.c:2285
kthread+0x3c2/0x780 kernel/kthread.c:463
ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
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: 10786 Comm: vhost-10785 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x17/0x70 kernel/kcov.c:217
Code: 03 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 34 24 65 48 8b 15 b8 21 1b 12 65 8b 05 c9 21 1b 12 00 01 ff 00 74 1d f6 c4 01 74 43 a9 00 00 0f 00 75 3c a9 00 00
RSP: 0018:ffffc9000475f8d8 EFLAGS: 00000287
RAX: 0000000080000000 RBX: 0000000000000000 RCX: ffffc9001a772000
RDX: ffff88802e0f8000 RSI: ffffffff82055704 RDI: 0000000000000007
RBP: 0000000000000001 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000fff
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS: 00007f90e05476c0(0000) GS:ffff8881247b5000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000027000 CR3: 0000000079cc6000 CR4: 00000000003526f0
Call Trace:
gup_fast_fallback+0xeb4/0x23f0 mm/gup.c:3226
pin_user_pages_fast+0xa7/0xf0 mm/gup.c:3338
set_bit_to_user drivers/vhost/vhost.c:2423 [inline]
log_write+0x267/0x320 drivers/vhost/vhost.c:2449
log_used.isra.0+0x170/0x1e0 drivers/vhost/vhost.c:2505
vhost_update_used_flags+0x2ff/0x3d0 drivers/vhost/vhost.c:2580
vhost_disable_notify drivers/vhost/vhost.c:3213 [inline]
vhost_disable_notify+0xba/0x180 drivers/vhost/vhost.c:3205
vhost_vsock_handle_tx_kick+0x18e/0xd20 drivers/vhost/vsock.c:498
vhost_run_work_list+0x18b/0x230 drivers/vhost/vhost.c:454
vhost_task_fn+0x162/0x460 kernel/vhost_task.c:49
ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245