rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5738/1:b..l P5618/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=29441, q=1044 ncpus=1)
task:syz-executor state:R running task stack:22400 pid:5618 tgid:5618 ppid:5612 task_flags:0x400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5526 [inline]
__schedule+0x17db/0x58f0 kernel/sched/core.c:7277
preempt_schedule_common+0x7f/0xd0 kernel/sched/core.c:7456
preempt_schedule_thunk+0x16/0x40 arch/x86/entry/thunk.S:12
__raw_spin_unlock include/linux/spinlock_api_smp.h:201 [inline]
_raw_spin_unlock+0x41/0x50 kernel/locking/spinlock.c:213
spin_unlock include/linux/spinlock.h:401 [inline]
copy_pte_range mm/memory.c:1429 [inline]
copy_pmd_range+0x5176/0x5c10 mm/memory.c:1490
copy_pud_range mm/memory.c:1527 [inline]
copy_p4d_range mm/memory.c:1551 [inline]
copy_page_range+0xc82/0x1290 mm/memory.c:1637
dup_mmap+0xf17/0x1dc0 mm/mmap.c:1819
dup_mm kernel/fork.c:1543 [inline]
copy_mm+0x11a/0x480 kernel/fork.c:1595
copy_process+0x1e75/0x43e0 kernel/fork.c:2310
kernel_clone+0x2d7/0x940 kernel/fork.c:2769
__do_sys_clone kernel/fork.c:2911 [inline]
__se_sys_clone kernel/fork.c:2895 [inline]
__x64_sys_clone+0x1b6/0x230 kernel/fork.c:2895
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f19c45c6bd2
RSP: 002b:00007fff2252db10 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007fff2252db10 RCX: 00007f19c45c6bd2
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 00007fff2252dc9c R08: 0000000000000000 R09: 0000000000000001
R10: 0000555576e9a7d0 R11: 0000000000000246 R12: 0000000000000001
R13: 00000000000927c0 R14: 000000000002d836 R15: 00007fff2252dcf0
task:udevd state:R running task stack:24776 pid:5738 tgid:5738 ppid:4984 task_flags:0x400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5526 [inline]
__schedule+0x17db/0x58f0 kernel/sched/core.c:7277
preempt_schedule_irq+0x4b/0x90 kernel/sched/core.c:7599
irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline]
irqentry_exit+0x14f/0x910 kernel/entry/common.c:167
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:lock_acquire+0x232/0x350 kernel/locking/lockdep.c:5947
Code: ff ff ff e8 50 25 42 0a f7 44 24 10 00 02 00 00 0f 84 38 ff ff ff 65 48 8b 05 a2 c0 f1 11 48 3b 44 24 50 75 33 fb 48 83 c4 58 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 6a 11 6d ff cc 48 8d 3d 97 48 da
RSP: 0018:ffffc90002fcf6a0 EFLAGS: 00000296
RAX: 9a59781dba042100 RBX: 0000000000000000 RCX: 0000000000000046
RDX: 000000006778aeb0 RSI: ffffffff8e69c03a RDI: ffffffff8c6da080
RBP: ffff888076a8ddc0 R08: ffffffff8177f1df R09: 0000000000000000
R10: dffffc0000000000 R11: ffffffff81b28a90 R12: ffffffff8ed5c8e0
R13: 0000000000000002 R14: 0000000000000000 R15: 0000000000000246
rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
rcu_read_lock include/linux/rcupdate.h:849 [inline]
class_rcu_constructor include/linux/rcupdate.h:1216 [inline]
unwind_next_frame+0xac/0x2550 arch/x86/kernel/unwind_orc.c:495
arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
unpoison_slab_object mm/kasan/common.c:340 [inline]
__kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366
kasan_slab_alloc include/linux/kasan.h:253 [inline]
slab_post_alloc_hook mm/slub.c:4683 [inline]
slab_alloc_node mm/slub.c:4996 [inline]
kmem_cache_alloc_lru_noprof+0x2a3/0x5f0 mm/slub.c:5029
shmem_alloc_inode+0x28/0x40 mm/shmem.c:5115
alloc_inode+0x6a/0x1b0 fs/inode.c:338
new_inode+0x1f/0x170 fs/inode.c:1171
__shmem_get_inode mm/shmem.c:3040 [inline]
shmem_get_inode+0x3a4/0xfe0 mm/shmem.c:3112
shmem_symlink+0xa2/0x4d0 mm/shmem.c:4063
vfs_symlink+0x18b/0x330 fs/namei.c:5794
filename_symlinkat+0x1cd/0x410 fs/namei.c:5819
__do_sys_symlink fs/namei.c:5846 [inline]
__se_sys_symlink+0x4d/0x2b0 fs/namei.c:5842
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1ab5d15527
RSP: 002b:00007ffd77e6b228 EFLAGS: 00000202 ORIG_RAX: 0000000000000058
RAX: ffffffffffffffda RBX: 00005605ea5989d0 RCX: 00007f1ab5d15527
RDX: fffffffffffffe68 RSI: 00007ffd77e6b230 RDI: 00005605ea576340
RBP: 000000000000019c R08: 0000000000000064 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00007ffd77e6b230
R13: 00005605ea583190 R14: 0000000000000008 R15: 00005605ea5989d0
rcu: rcu_preempt kthread starved for 10502 jiffies! g29441 f0x0 RCU_GP_WAIT_FQS(5) ->state=R ->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:27856 pid:17 tgid:17 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5526 [inline]
__schedule+0x17db/0x58f0 kernel/sched/core.c:7277
__schedule_loop kernel/sched/core.c:7354 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7369
schedule_timeout+0x152/0x2c0 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x30c/0x11f0 kernel/rcu/tree.c:2122
rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2330
kthread+0x38b/0x480 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 5632 Comm: kworker/u9:6 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2026
Workqueue: 0x0 (hci6)
RIP: 0010:finish_task_switch+0x413/0xc60 kernel/sched/core.c:5377
Code: 04 00 00 41 c7 84 24 20 0e 00 00 00 00 00 00 0f 1f 44 00 00 49 83 c4 48 4c 89 e7 e8 37 07 52 0a e8 22 18 3a 00 fb 4c 8b 65 c8 <49> 8d bc 24 10 17 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 30 84 c0
RSP: 0018:ffffc9000303fa60 EFLAGS: 00000202
RAX: 000000000012da3d RBX: ffff8880b863c8e0 RCX: 8000000000000001
RDX: 0000000000000000 RSI: ffffffff8e413808 RDI: ffffffff8c6da080
RBP: ffffc9000303fab0 R08: ffffffff907a3e7f R09: 1ffffffff20f47cf
R10: dffffc0000000000 R11: fffffbfff20f47d0 R12: ffff8880340f9f40
R13: ffff8880b863c8a8 R14: dffffc0000000000 R15: 1ffff110170c791c
FS: 0000000000000000(0000) GS:ffff888124cd1000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f1ab6420000 CR3: 000000002f357000 CR4: 0000000000350ef0
Call Trace:
context_switch kernel/sched/core.c:5529 [inline]
__schedule+0x17e3/0x58f0 kernel/sched/core.c:7277
__schedule_loop kernel/sched/core.c:7354 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7369
worker_thread+0xc12/0xfb0 kernel/workqueue.c:3575
kthread+0x38b/0x480 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245