rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5942/1:b..l P5191/1:b..l P5837/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=13469, q=1056 ncpus=2)
task:udevd state:R running task stack:25816 pid:5837 tgid:5837 ppid:5191 task_flags:0x400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5282 [inline]
__schedule+0x14ed/0x5040 kernel/sched/core.c:6894
preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7221
irqentry_exit+0x5e3/0x670 kernel/entry/common.c:216
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:__rcu_read_lock+0x30/0x60 kernel/rcu/tree_plugin.h:416
Code: 48 8b 1c 25 08 90 a1 92 48 81 c3 84 04 00 00 48 89 d8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 0f b6 04 08 84 c0 75 18 ff 03 <8b> 03 3d 00 00 00 40 7d 07 5b e9 c1 fc b8 09 cc 90 0f 0b 90 eb f3
RSP: 0018:ffffc9000403f088 EFLAGS: 00000202
RAX: 0000000000000000 RBX: ffff88803482c104 RCX: dffffc0000000000
RDX: dffffc0000000000 RSI: ffffffff8445d92d RDI: ffffc9000403f168
RBP: dffffc0000000000 R08: ffffc9000403f230 R09: 0000000000000004
R10: ffffc9000403f1b8 R11: ffffffff81acb2b0 R12: 1ffff92000807e2d
R13: ffffc9000403f1a0 R14: ffffc9000403f168 R15: ffffc9000403f5c0
rcu_read_lock include/linux/rcupdate.h:848 [inline]
class_rcu_constructor include/linux/rcupdate.h:1193 [inline]
unwind_next_frame+0x9e/0x23d0 arch/x86/kernel/unwind_orc.c:495
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
__kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415
kasan_kmalloc include/linux/kasan.h:263 [inline]
__do_kmalloc_node mm/slub.c:5677 [inline]
__kmalloc_noprof+0x41d/0x800 mm/slub.c:5689
kmalloc_noprof include/linux/slab.h:962 [inline]
kzalloc_noprof include/linux/slab.h:1200 [inline]
tomoyo_encode2 security/tomoyo/realpath.c:45 [inline]
tomoyo_encode+0x28b/0x550 security/tomoyo/realpath.c:80
tomoyo_realpath_from_path+0x58d/0x5d0 security/tomoyo/realpath.c:283
tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
tomoyo_check_open_permission+0x1c1/0x3b0 security/tomoyo/file.c:776
security_file_open+0xb1/0x270 security/security.c:2636
do_dentry_open+0x384/0x14e0 fs/open.c:939
vfs_open+0x3b/0x340 fs/open.c:1094
do_open fs/namei.c:4634 [inline]
path_openat+0x2de0/0x3840 fs/namei.c:4793
do_filp_open+0x1fa/0x410 fs/namei.c:4820
do_sys_openat2+0x121/0x200 fs/open.c:1391
do_sys_open fs/open.c:1397 [inline]
__do_sys_openat fs/open.c:1413 [inline]
__se_sys_openat fs/open.c:1408 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1408
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f7c420a7407
RSP: 002b:00007ffd77ef7e30 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f7c42783880 RCX: 00007f7c420a7407
RDX: 0000000000080000 RSI: 0000557a358fe540 RDI: ffffffffffffff9c
RBP: 0000557a358fe540 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000009
task:udevd state:R running task stack:25712 pid:5191 tgid:5191 ppid:1 task_flags:0x400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5282 [inline]
__schedule+0x14ed/0x5040 kernel/sched/core.c:6894
preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7078
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:179 [inline]
_raw_spin_unlock_irqrestore+0x74/0x80 kernel/locking/spinlock.c:194
spin_unlock_irqrestore include/linux/spinlock.h:410 [inline]
__wake_up_common_lock+0x190/0x1f0 kernel/sched/wait.c:127
sock_def_readable+0x1eb/0x530 net/core/sock.c:3611
__netlink_sendskb net/netlink/af_netlink.c:1263 [inline]
netlink_sendskb+0xa1/0x140 net/netlink/af_netlink.c:1269
netlink_unicast+0x397/0x9e0 net/netlink/af_netlink.c:1359
netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1894
sock_sendmsg_nosec+0x18f/0x1d0 net/socket.c:737
__sock_sendmsg net/socket.c:752 [inline]
____sys_sendmsg+0x577/0x880 net/socket.c:2610
___sys_sendmsg+0x21f/0x2a0 net/socket.c:2664
__sys_sendmsg net/socket.c:2696 [inline]
__do_sys_sendmsg net/socket.c:2701 [inline]
__se_sys_sendmsg net/socket.c:2699 [inline]
__x64_sys_sendmsg+0x19b/0x260 net/socket.c:2699
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f7c420a7407
RSP: 002b:00007ffd77efd3d0 EFLAGS: 00000202 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f7c42783880 RCX: 00007f7c420a7407
RDX: 0000000000000000 RSI: 00007ffd77efd430 RDI: 0000000000000004
RBP: 0000557a358ef660 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00000000000000b2
R13: 0000557a358e79e0 R14: 0000000000000000 R15: 0000000000000000
task:syz-executor state:R running task stack:19496 pid:5942 tgid:5942 ppid:5937 task_flags:0x400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5282 [inline]
__schedule+0x14ed/0x5040 kernel/sched/core.c:6894
preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7221
irqentry_exit+0x5e3/0x670 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:228 [inline]
RIP: 0010:unwind_next_frame+0x214/0x23d0 arch/x86/kernel/unwind_orc.c:510
Code: ef 08 8b 15 7e e4 47 0c 8d 42 ff 44 39 f8 0f 86 78 04 00 00 44 89 f8 4c 8d 2c 85 9c f3 e2 90 4c 89 e8 48 c1 e8 03 0f b6 04 28 <84> c0 48 89 eb 0f 85 2c 1c 00 00 45 8b 6d 00 44 89 f8 ff c0 48 8d
RSP: 0000:ffffc9000400f1d8 EFLAGS: 00000a02
RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000080000000
RDX: 00000000000a6153 RSI: ffffffff8be08c40 RDI: ffffffff8be08c00
RBP: dffffc0000000000 R08: ffffffff8173fd75 R09: ffffffff8e13efa0
R10: ffffc9000400f2f8 R11: ffffffff81acb2b0 R12: ffffffff8b5d8ff0
R13: ffffffff910c69d8 R14: ffffc9000400f2a8 R15: 00000000000a5d8f
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
save_stack+0xf5/0x1f0 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+0x23d/0x2a0 mm/page_alloc.c:1887
prep_new_page mm/page_alloc.c:1895 [inline]
get_page_from_freelist+0x23a5/0x2440 mm/page_alloc.c:3948
__alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5257
alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2486
folio_alloc_mpol_noprof mm/mempolicy.c:2505 [inline]
vma_alloc_folio_noprof+0xe4/0x200 mm/mempolicy.c:2540
folio_prealloc+0x30/0x180 mm/memory.c:-1
wp_page_copy mm/memory.c:3719 [inline]
do_wp_page+0x1231/0x5810 mm/memory.c:4180
handle_pte_fault mm/memory.c:6271 [inline]
__handle_mm_fault mm/memory.c:6393 [inline]
handle_mm_fault+0x14c5/0x32b0 mm/memory.c:6562
do_user_addr_fault+0xa7c/0x1380 arch/x86/mm/fault.c:1336
handle_page_fault arch/x86/mm/fault.c:1476 [inline]
exc_page_fault+0x71/0xd0 arch/x86/mm/fault.c:1532
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0033:0x7f0dab185d16
RSP: 002b:00007ffc7b000d40 EFLAGS: 00010202
RAX: 000000000000000d RBX: 0000000000000000 RCX: 00007f0dab185e93
RDX: 000000000000000d RSI: 0000000000000000 RDI: 0000000001200011
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001
R10: 00005555845807d0 R11: 0000000000000246 R12: 000000000000000d
R13: ffffffffffffffa8 R14: 0000000000000006 R15: 00007ffc7b000ed0
rcu: rcu_preempt kthread starved for 10617 jiffies! g13469 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:27640 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5282 [inline]
__schedule+0x14ed/0x5040 kernel/sched/core.c:6894
__schedule_loop kernel/sched/core.c:6976 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6991
schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x301/0x11b0 kernel/rcu/tree.c:2095
rcu_gp_kthread+0x9b/0x2d0 kernel/rcu/tree.c:2297
kthread+0x389/0x480 kernel/kthread.c:467
ret_from_fork+0x510/0xa50 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:
CPU: 0 UID: 0 PID: 6156 Comm: syz.0.51 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:188 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x29/0x50 kernel/locking/spinlock.c:202
Code: 90 f3 0f 1e fa 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 ca fb 3d f6 48 89 df e8 a2 6f 3e f6 e8 ad 5c 68 f6 fb bf 01 00 00 00 92 8a 30 f6 65 8b 05 6b 67 41 07 85 c0 74 07 5b e9 91 47 00 00
RSP: 0018:ffffc90003da7c80 EFLAGS: 00000206
RAX: 00000000037114db RBX: ffff888031252e40 RCX: 0000000080000001
RDX: 0000000000000000 RSI: ffffffff8d9a0b7f RDI: 0000000000000001
RBP: 0000000000000011 R08: ffffffff8fa25d77 R09: 1ffffffff1f44bae
R10: dffffc0000000000 R11: fffffbfff1f44baf R12: 1ffff1100624a61b
R13: 0000000000000000 R14: 0000000004000000 R15: ffff8880312530d8
FS: 00007f6e1e9dd6c0(0000) GS:ffff888125c07000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6e1e9dcf40 CR3: 0000000033b14000 CR4: 00000000003526f0
Call Trace:
spin_unlock_irq include/linux/spinlock.h:404 [inline]
get_signal+0x11a7/0x1340 kernel/signal.c:3037
arch_do_signal_or_restart+0x9a/0x7a0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:41 [inline]
exit_to_user_mode_loop+0x87/0x4e0 kernel/entry/common.c:75
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [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+0x2c1/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6e1f38f749
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f6e1e9dd0e8 EFLAGS: 00000246
RAX: fffffffffffffffc RBX: 00007f6e1f5e6098 RCX: 00007f6e1f38f749
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f6e1f5e6098
RBP: 00007f6e1f5e6090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f6e1f5e6128 R14: 00007fff755a0f80 R15: 00007fff755a1068