rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P11156/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=36521, q=472938 ncpus=2)
task:syz.1.1989 state:R running task stack:24384 pid:11156 tgid:11153 ppid:5818 task_flags:0x400040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5298 [inline]
__schedule+0x15dd/0x52d0 kernel/sched/core.c:6911
preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7238
irqentry_exit+0x599/0x620 kernel/entry/common.c:239
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_acquire+0x20b/0x2e0 kernel/locking/lockdep.c:5872
Code: e9 30 ff ff ff e8 85 a4 0d 0a f7 c3 00 02 00 00 0f 84 38 ff ff ff 65 48 8b 05 01 02 7b 11 48 3b 44 24 30 75 33 fb 48 83 c4 38 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 d1 b2 6e ff cc 48 8d 3d 3e 92 73
RSP: 0018:ffffc90003417098 EFLAGS: 00000282
RAX: b9d6a0a9a003e600 RBX: 0000000000000246 RCX: 0000000000000046
RDX: 0000000088789759 RSI: ffffffff8e16b29d RDI: ffffffff8c27d100
RBP: 0000000000000000 R08: ffffffff81767e95 R09: ffffffff8e75e5e0
R10: dffffc0000000000 R11: ffffffff81b0d0f0 R12: 0000000000000002
R13: ffffffff8e75e5e0 R14: 0000000000000000 R15: 0000000000000000
rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
rcu_read_lock include/linux/rcupdate.h:850 [inline]
class_rcu_constructor include/linux/rcupdate.h:1193 [inline]
unwind_next_frame+0xc2/0x23c0 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
save_stack+0x122/0x230 mm/page_owner.c:165
__set_page_owner+0x8d/0x4c0 mm/page_owner.c:341
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x231/0x280 mm/page_alloc.c:1889
prep_new_page mm/page_alloc.c:1897 [inline]
get_page_from_freelist+0x24dc/0x2580 mm/page_alloc.c:3962
__alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5250
alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2490
folio_alloc_mpol_noprof+0x39/0x70 mm/mempolicy.c:2509
shmem_alloc_folio mm/shmem.c:1930 [inline]
shmem_alloc_and_add_folio+0x445/0xf80 mm/shmem.c:1972
shmem_get_folio_gfp+0x5a9/0x1670 mm/shmem.c:2567
shmem_get_folio mm/shmem.c:2673 [inline]
shmem_write_begin+0x16c/0x330 mm/shmem.c:3327
generic_perform_write+0x2e2/0x8f0 mm/filemap.c:4319
shmem_file_write_iter+0xf8/0x120 mm/shmem.c:3502
new_sync_write fs/read_write.c:595 [inline]
vfs_write+0x61d/0xb90 fs/read_write.c:688
ksys_write+0x150/0x270 fs/read_write.c:740
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff069d5d04e
RSP: 002b:00007ff06aca4da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007ff06aca56c0 RCX: 00007ff069d5d04e
RDX: 0000000001000000 RSI: 00007ff05fa00000 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003
R13: 00007ff06aca4ee0 R14: 00007ff06aca4ea0 R15: 00007ff05fa00000
rcu: rcu_preempt kthread starved for 846 jiffies! g36521 f0x2 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:27560 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5298 [inline]
__schedule+0x15dd/0x52d0 kernel/sched/core.c:6911
__schedule_loop kernel/sched/core.c:6993 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7008
schedule_timeout+0x158/0x2c0 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x312/0x11d0 kernel/rcu/tree.c:2095
rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2297
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x51e/0xb90 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:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 6104 Comm: udevd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
RIP: 0010:__lock_acquire+0x865/0x2cf0 kernel/locking/lockdep.c:-1
Code: 29 cb 89 ca c1 c2 06 31 da 01 c1 29 d0 89 d6 c1 c6 08 31 c6 01 ca 29 f1 89 f3 c1 c3 10 31 cb 01 d6 29 da 89 dd c1 c5 13 31 d5 <01> f3 29 ee 01 eb c1 c5 04 31 f5 48 c1 e5 20 83 3d b9 67 70 0e 00
RSP: 0018:ffffc900000073f8 EFLAGS: 00000006
RAX: 000000006fa691b2 RBX: 00000000e4e7f0d0 RCX: 00000000e957452e
RDX: 00000000bd47baaa RSI: 00000000582db92a RDI: ffff8880334abd00
RBP: 000000003bc09d95 R08: ffffffff81767e95 R09: ffffffff8e75e5e0
R10: dffffc0000000000 R11: ffffffff81b0d0f0 R12: ffff8880334ac8d0
R13: ffff8880334ac8d0 R14: ffff8880334abd00 R15: 0000000000000003
FS: 0000000000000000(0000) GS:ffff888125457000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc51aa00218 CR3: 000000007c47e000 CR4: 0000000000350ef0
Call Trace:
lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868
rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
rcu_read_lock include/linux/rcupdate.h:850 [inline]
class_rcu_constructor include/linux/rcupdate.h:1193 [inline]
unwind_next_frame+0xc2/0x23c0 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
kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:253 [inline]
__kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
kasan_slab_free include/linux/kasan.h:235 [inline]
slab_free_hook mm/slub.c:2685 [inline]
slab_free mm/slub.c:6165 [inline]
kfree+0x1c1/0x630 mm/slub.c:6483
dummy_timer+0xb59/0x45d0 drivers/usb/gadget/udc/dummy_hcd.c:1989
__run_hrtimer kernel/time/hrtimer.c:1785 [inline]
__hrtimer_run_queues+0x53a/0xcc0 kernel/time/hrtimer.c:1849
hrtimer_run_softirq+0x182/0x5a0 kernel/time/hrtimer.c:1866
handle_softirqs+0x22a/0x870 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0x5f/0x150 kernel/softirq.c:723
irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:arch_static_branch arch/x86/include/asm/jump_label.h:37 [inline]
RIP: 0010:trace_notifier_run include/trace/events/notifier.h:59 [inline]
RIP: 0010:notifier_call_chain+0x10c/0x400 kernel/notifier.c:84
Code: fe ff 41 89 c6 31 ff 89 c6 e8 40 f7 33 00 45 85 f6 0f 84 3f 01 00 00 41 80 3c 1f 00 74 08 4c 89 e7 e8 08 40 9e 00 4d 8b 2c 24 <0f> 1f 44 00 00 e8 da f2 33 00 65 44 8b 2d 36 ce 8a 11 bf 07 00 00
RSP: 0018:ffffc90005caf9c0 EFLAGS: 00000246
RAX: ffffffff8191c1d0 RBX: dffffc0000000000 RCX: 0000000000000000
RDX: ffff8880334abd00 RSI: 0000000000000001 RDI: 0000000000000000
RBP: 00000000fffffffc R08: ffffffff9011ccb7 R09: 1ffffffff2023996
R10: dffffc0000000000 R11: fffffbfff2023997 R12: ffffffff8fc4a760
R13: ffffffff89c90720 R14: 0000000000000001 R15: 1ffffffff1f894ec
blocking_notifier_call_chain+0x6a/0x90 kernel/notifier.c:380
netlink_release+0x123b/0x1ad0 net/netlink/af_netlink.c:761
__sock_release net/socket.c:662 [inline]
sock_close+0xc3/0x240 net/socket.c:1455
__fput+0x44f/0xa70 fs/file_table.c:469
task_work_run+0x1d9/0x270 kernel/task_work.c:233
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x70f/0x23c0 kernel/exit.c:976
do_group_exit+0x21b/0x2d0 kernel/exit.c:1118
__do_sys_exit_group kernel/exit.c:1129 [inline]
__se_sys_exit_group kernel/exit.c:1127 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1127
x64_sys_call+0x221a/0x2240 arch/x86/include/generated/asm/syscalls_64.h:232
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa31b6f16c5
Code: Unable to access opcode bytes at 0x7fa31b6f169b.
RSP: 002b:00007ffc1b03bd38 EFLAGS: 00000256 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 000055b254f3a360 RCX: 00007fa31b6f16c5
RDX: 00000000000000e7 RSI: fffffffffffffe68 RDI: 0000000000000000
RBP: 000055b254de9910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000256 R12: 0000000000000000
R13: 00007ffc1b03bd80 R14: 0000000000000000 R15: 0000000000000000