rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P14359/1:b..l P15859/1:b..l P5191/1:b..l P15949/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=81677, q=450 ncpus=2)
task:syz.2.2469 state:R running task stack:26656 pid:15949 tgid:15948 ppid:5817 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:lock_acquire+0x222/0x340 kernel/locking/lockdep.c:5872
Code: ff ff ff e8 60 9c bf 09 f7 44 24 08 00 02 00 00 0f 84 3a ff ff ff 65 48 8b 05 7a 9a 03 11 48 3b 44 24 58 75 33 fb 48 83 c4 60 <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 48 8d 3d 97 ad 07
RSP: 0018:ffffc9000bcbf660 EFLAGS: 00000286
RAX: b6d72332da64f900 RBX: 0000000000000000 RCX: 0000000000000046
RDX: 000000005a44979c RSI: ffffffff8db845c0 RDI: ffffffff8be08c60
RBP: ffffffff8932e21e R08: ffffffff8932e21e R09: ffffffff8e13efa0
R10: dffffc0000000000 R11: fffffbfff1f44baf R12: 0000000000000002
R13: ffffffff8e13efa0 R14: 0000000000000000 R15: 0000000000000246
rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
rcu_read_lock include/linux/rcupdate.h:850 [inline]
sock_def_readable+0xce/0x530 net/core/sock.c:3608
unix_dgram_sendmsg+0xdfb/0x1840 net/unix/af_unix.c:2286
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_sendmmsg+0x227/0x430 net/socket.c:2753
__do_sys_sendmmsg net/socket.c:2780 [inline]
__se_sys_sendmmsg net/socket.c:2777 [inline]
__x64_sys_sendmmsg+0xa0/0xc0 net/socket.c:2777
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: 0033:0x7f9f0b58f749
RSP: 002b:00007f9f0c443038 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00007f9f0b7e5fa0 RCX: 00007f9f0b58f749
RDX: 0000000000000318 RSI: 00002000000bd000 RDI: 0000000000000005
RBP: 00007f9f0b613f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f9f0b7e6038 R14: 00007f9f0b7e5fa0 R15: 00007fff480b2388
task:udevd state:R running task stack:23288 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: 0033:0x7f373a0a7407
RSP: 002b:00007ffd40f8a9f0 EFLAGS: 00000202 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f373a884880 RCX: 00007f373a0a7407
RDX: 0000000000000000 RSI: 00007ffd40f8aa50 RDI: 0000000000000004
RBP: 000055f86c0b3fc0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000091
R13: 000055f86c0b39e0 R14: 0000000000000000 R15: 0000000000000000
task:udevd state:R running task stack:26616 pid:15859 tgid:15859 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:lockdep_enabled kernel/locking/lockdep.c:121 [inline]
RIP: 0010:lock_acquire+0x98/0x340 kernel/locking/lockdep.c:5844
Code: 0f 84 d4 00 00 00 48 8b b4 24 90 00 00 00 4c 89 ef e8 6c 6c 89 00 83 3d 65 99 04 0e 00 0f 84 cf 00 00 00 65 8b 05 88 e1 03 11 <85> c0 0f 85 c0 00 00 00 65 48 8b 04 25 08 90 a1 92 83 b8 04 0b 00
RSP: 0018:ffffc90004f4f378 EFLAGS: 00000202
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000080000001
RDX: 0000000000000000 RSI: ffffffff8173fd92 RDI: 1ffffffff1c27df4
RBP: ffffffff8173fd75 R08: 0000000000000000 R09: 0000000000000000
R10: ffffc90004f4f538 R11: ffffffff81acb2b0 R12: 0000000000000002
R13: ffffffff8e13efa0 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+0xc2/0x23d0 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
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:4969 [inline]
slab_alloc_node mm/slub.c:5283 [inline]
kmem_cache_alloc_noprof+0x37d/0x710 mm/slub.c:5290
lsm_file_alloc security/security.c:169 [inline]
security_file_alloc+0x34/0x330 security/security.c:2380
init_file+0x93/0x2f0 fs/file_table.c:159
alloc_empty_file+0x6e/0x1d0 fs/file_table.c:241
path_openat+0x108/0x3840 fs/namei.c:4779
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: 0033:0x7f373a0a7407
RSP: 002b:00007ffd40f86300 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f373a884880 RCX: 00007f373a0a7407
RDX: 0000000000080000 RSI: 00007ffd40f86470 RDI: ffffffffffffff9c
RBP: 0000000000000008 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 000055f85bb647f5
R13: 000055f85bb647f5 R14: 0000000000000001 R15: 000055f85bb7f140
task:udevd state:R running task stack:23288 pid:14359 tgid:14359 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:lock_release+0x80/0x3b0 kernel/locking/lockdep.c:5881
Code: 68 04 0e 00 0f 84 1d 02 00 00 65 8b 05 d9 b0 03 11 85 c0 0f 85 0e 02 00 00 65 4c 8b 3c 25 08 90 a1 92 41 83 bf 04 0b 00 00 00 <0f> 85 f7 01 00 00 49 81 3e e0 53 65 93 0f 84 ea 01 00 00 9c 5b fa
RSP: 0018:ffffc9000ea178c8 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000080000001
RDX: 0000000000000000 RSI: ffffffff8be08c40 RDI: ffffffff8be08c00
RBP: 0000000000000000 R08: ffffffff81cfe6e6 R09: ffffffff8e13efa0
R10: ffffc9000ea17a18 R11: ffffffff81acb2b0 R12: 000000000000066a
R13: ffffffff81cfe6e6 R14: ffffffff8e13efa0 R15: ffff88802fa21e40
rcu_lock_release include/linux/rcupdate.h:322 [inline]
rcu_read_unlock include/linux/rcupdate.h:881 [inline]
is_bpf_text_address+0x28d/0x2b0 kernel/bpf/core.c:750
kernel_text_address+0xa5/0xe0 kernel/extable.c:125
__kernel_text_address+0xd/0x40 kernel/extable.c:79
unwind_get_return_address+0x4d/0x90 arch/x86/kernel/unwind_orc.c:385
arch_stack_walk+0xfc/0x150 arch/x86/kernel/stacktrace.c:26
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
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:2556 [inline]
slab_free mm/slub.c:6690 [inline]
kmem_cache_free+0x197/0x620 mm/slub.c:6801
do_symlinkat+0x3be/0x420 fs/namei.c:5628
__do_sys_symlink fs/namei.c:5640 [inline]
__se_sys_symlink fs/namei.c:5638 [inline]
__x64_sys_symlink+0x7a/0x90 fs/namei.c:5638
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: 0033:0x7f373a115527
RSP: 002b:00007ffd40f89aa8 EFLAGS: 00000206 ORIG_RAX: 0000000000000058
RAX: ffffffffffffffda RBX: 00007ffd40f8a480 RCX: 00007f373a115527
RDX: 0000000000000000 RSI: 00007ffd40f8a480 RDI: 00007ffd40f89b60
RBP: 00007ffd40f8a491 R08: 0000000000000075 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 000055f86c0b44d5
R13: 00007ffd40f89b60 R14: 000055f85bb646d7 R15: 000055f86c0b44d0
rcu: rcu_preempt kthread starved for 10643 jiffies! g81677 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:27232 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: 1 UID: 0 PID: 0 Comm: swapper/1 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82
Code: cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 43 be 2a 00 f3 0f 1e fa fb f4 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90000197e20 EFLAGS: 000002c2
RAX: 00000000026ec679 RBX: ffffffff8197161e RCX: 0000000080000001
RDX: 0000000000000001 RSI: ffffffff8d9a0b7f RDI: ffffffff8be08c60
RBP: ffffc90000197f10 R08: ffff8880b873375b R09: 1ffff110170e66eb
R10: dffffc0000000000 R11: ffffed10170e66ec R12: ffffffff8fa25d70
R13: 1ffff11003ad4b58 R14: 0000000000000001 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff888125d07000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000072c4a000 CR4: 00000000003526f0
Call Trace:
arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:767
default_idle_call+0x73/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:191 [inline]
do_idle+0x1be/0x4d0 kernel/sched/idle.c:332
cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:430
start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:312
common_startup_64+0x13e/0x147