rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P8956/1:b..l P5202/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=31069, q=943 ncpus=2)
task:udevd state:R running task stack:22712 pid:5202 tgid:5202 ppid:1 task_flags:0x400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5258 [inline]
__schedule+0x150e/0x5070 kernel/sched/core.c:6866
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7193
irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:unwind_next_frame+0xcb9/0x23d0 arch/x86/kernel/unwind_orc.c:596
Code: 0f 85 6f 11 00 00 49 89 df 49 c1 ef 03 41 0f b6 04 2f 84 c0 0f 85 7f 11 00 00 0f b6 76 01 83 e6 07 83 fe 04 0f 84 4e 04 00 00 <83> fe 03 0f 84 f5 01 00 00 83 fe 02 0f 85 a8 07 00 00 4c 89 7c 24
RSP: 0018:ffffc900021af0d8 EFLAGS: 00000293
RAX: 0000000000000000 RBX: ffffffff90430629 RCX: ffffffff8fc2fda4
RDX: ffffffff90430624 RSI: 0000000000000002 RDI: ffffffff8be07900
RBP: dffffc0000000000 R08: 000000000000000a R09: ffffffff8e13f2e0
R10: ffffc900021af1f8 R11: ffffffff81ad9d50 R12: ffffc900021af518
R13: ffffc900021af1f8 R14: ffffc900021af1a8 R15: 1ffffffff20860c5
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
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:2540 [inline]
slab_free mm/slub.c:6674 [inline]
kfree+0x1c0/0x660 mm/slub.c:6882
tomoyo_realpath_from_path+0x598/0x5d0 security/tomoyo/realpath.c:286
tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
tomoyo_check_open_permission+0x1c1/0x3b0 security/tomoyo/file.c:771
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:4627 [inline]
path_openat+0x2de0/0x3840 fs/namei.c:4786
do_filp_open+0x1fa/0x410 fs/namei.c:4813
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+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5a66ca7407
RSP: 002b:00007ffc94aecf40 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f5a67419880 RCX: 00007f5a66ca7407
RDX: 0000000000080141 RSI: 000055ce5cad202e RDI: ffffffffffffff9c
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000000001a4 R11: 0000000000000202 R12: 00000000ffffffff
R13: 00000000ffffffff R14: ffffffffffffffff R15: 0000000000000000
task:syz.4.617 state:R running task stack:23688 pid:8956 tgid:8954 ppid:5832 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5258 [inline]
__schedule+0x150e/0x5070 kernel/sched/core.c:6866
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7193
irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:rcu_lock_release include/linux/rcupdate.h:341 [inline]
RIP: 0010:rcu_read_unlock include/linux/rcupdate.h:897 [inline]
RIP: 0010:class_rcu_destructor include/linux/rcupdate.h:1195 [inline]
RIP: 0010:unwind_next_frame+0x1aa2/0x23d0 arch/x86/kernel/unwind_orc.c:695
Code: 74 28 80 3d 90 d9 17 0e 00 75 1f c6 05 87 d9 17 0e 01 48 c7 c7 00 91 88 8b be 80 03 00 00 48 c7 c2 a0 91 88 8b e8 3e 71 2a 00 <48> c7 c7 e0 f2 13 8e 4c 89 fe e8 bf 54 2a 00 e8 7a 07 34 00 89 d8
RSP: 0018:ffffc90002f46cf8 EFLAGS: 00000202
RAX: 0000000000000001 RBX: ffffffff90ba6701 RCX: 33a30d2acbe6e000
RDX: ffffc90002f46e01 RSI: ffffffff8be07940 RDI: ffffffff8be07900
RBP: dffffc0000000000 R08: ffffc90002f47ea0 R09: 0000000000000000
R10: ffffc90002f46e18 R11: fffff520005e8dc5 R12: ffffc90002f47eb0
R13: ffffc90002f40000 R14: ffffc90002f46dc8 R15: ffffffff81742f85
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]
__kmalloc_cache_noprof+0x3e2/0x700 mm/slub.c:5780
kmalloc_noprof include/linux/slab.h:957 [inline]
kzalloc_noprof include/linux/slab.h:1094 [inline]
ref_tracker_alloc+0x133/0x460 lib/ref_tracker.c:271
__netdev_tracker_alloc include/linux/netdevice.h:4415 [inline]
netdev_hold include/linux/netdevice.h:4444 [inline]
dst_init+0xe6/0x460 net/core/dst.c:52
dst_alloc+0x12a/0x170 net/core/dst.c:93
rt_dst_clone+0x52/0x680 net/ipv4/route.c:1679
ip_mc_finish_output+0xe9/0x2d0 net/ipv4/ip_output.c:357
NF_HOOK include/linux/netfilter.h:318 [inline]
ip_mc_output+0x25c/0x590 net/ipv4/ip_output.c:401
ip_local_out net/ipv4/ip_output.c:131 [inline]
ip_send_skb+0x74/0x100 net/ipv4/ip_output.c:1508
udp_send_skb+0xaf1/0x14c0 net/ipv4/udp.c:1195
udp_sendmsg+0x195a/0x2170 net/ipv4/udp.c:1484
sock_sendmsg_nosec+0x128/0x1d0 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+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f622618f749
RSP: 002b:00007f6226f3f038 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00007f62263e6090 RCX: 00007f622618f749
RDX: 000000000800001d RSI: 0000200000007fc0 RDI: 000000000000000e
RBP: 00007f6226213f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000300 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f62263e6128 R14: 00007f62263e6090 R15: 00007ffec9e91908
rcu: rcu_preempt kthread starved for 10608 jiffies! g31069 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:27168 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5258 [inline]
__schedule+0x150e/0x5070 kernel/sched/core.c:6866
__schedule_loop kernel/sched/core.c:6948 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6963
schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x599/0xb30 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: 0 Comm: swapper/0 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 33 9e 2a 00 f3 0f 1e fa fb f4 48 ee 02 00 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffffff8de07d80 EFLAGS: 000002c6
RAX: 44896a1968284200 RBX: ffffffff819786ba RCX: 44896a1968284200
RDX: 0000000000000001 RSI: ffffffff8d997e54 RDI: ffffffff8be07960
RBP: ffffffff8de07ea8 R08: ffff8880b86336db R09: 1ffff110170c66db
R10: dffffc0000000000 R11: ffffed10170c66dc R12: ffffffff8fa22f70
R13: 1ffffffff1bd29b8 R14: 0000000000000000 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888125c25000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000002d966000 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+0x1ea/0x520 kernel/sched/idle.c:332
cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:430
rest_init+0x2de/0x300 init/main.c:758
start_kernel+0x3ac/0x400 init/main.c:1208
x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310
x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:291
common_startup_64+0x13e/0x147