rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P9023/1:b..l P5196/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=58117, q=329 ncpus=2)
task:udevd state:R running task stack:23288 pid:5196 tgid:5196 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:rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
RIP: 0010:rcu_read_lock include/linux/rcupdate.h:867 [inline]
RIP: 0010:class_rcu_constructor include/linux/rcupdate.h:1195 [inline]
RIP: 0010:kernfs_root+0x33/0x230 fs/kernfs/kernfs-internal.h:75
Code: 89 fe e8 40 24 5d ff e8 7b bc 43 ff 48 8d 1d 00 00 00 00 48 c7 c7 e0 f2 13 8e 31 f6 31 d2 b9 02 00 00 00 45 31 c0 45 31 c9 53 28 d9 39 ff 48 83 c4 08 e8 0f 24 f9 08 89 c5 31 ff 89 c6 e8 44
RSP: 0018:ffffc900031a77a8 EFLAGS: 00000246
RAX: 0000000000000001 RBX: ffffffff8264942c RCX: 0000000000000002
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8e13f2e0
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: ffff88802f2101e0 R11: ffffffff8264a7a0 R12: 0000000000000001
R13: ffffffff8264a7a0 R14: ffff88801de80000 R15: ffff88801de80000
kernfs_iop_permission+0x6c/0x430 fs/kernfs/inode.c:287
do_inode_permission fs/namei.c:526 [inline]
inode_permission+0x41f/0x5f0 fs/namei.c:596
lookup_inode_permission_may_exec fs/namei.c:636 [inline]
may_lookup fs/namei.c:1900 [inline]
link_path_walk+0xaad/0x18d0 fs/namei.c:2537
path_openat+0x2b0/0x3840 fs/namei.c:4782
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: 0033:0x7f5d57bdd407
RSP: 002b:00007ffe7d812ed0 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f5d57b51880 RCX: 00007f5d57bdd407
RDX: 0000000000080000 RSI: 00007ffe7d813050 RDI: ffffffffffffff9c
RBP: 0000000000000008 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00005566feb707f5
R13: 00005566feb707f5 R14: 0000000000000001 R15: 00007ffe7d8176a0
task:udevd state:R running task stack:23280 pid:9023 tgid:9023 ppid:5196 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_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_acquire+0x16c/0x340 kernel/locking/lockdep.c:5872
Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 44 41 01 11 <48> 3b 44 24 58 0f 85 e5 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc90003387138 EFLAGS: 00000206
RAX: 0375d9d7b7a5cb00 RBX: 0000000000000000 RCX: 0375d9d7b7a5cb00
RDX: 0000000004597770 RSI: ffffffff8db7ed49 RDI: ffffffff8be07960
RBP: ffffffff81742f85 R08: ffffffff81742f85 R09: ffffffff8e13f2e0
R10: ffffc90003387358 R11: fffff52000670e6d R12: 0000000000000002
R13: ffffffff8e13f2e0 R14: 0000000000000000 R15: 0000000000000246
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:867 [inline]
class_rcu_constructor include/linux/rcupdate.h:1195 [inline]
unwind_next_frame+0xc2/0x23d0 arch/x86/kernel/unwind_orc.c:495
__unwind_start+0x5b9/0x760 arch/x86/kernel/unwind_orc.c:773
unwind_start arch/x86/include/asm/unwind.h:64 [inline]
arch_stack_walk+0xe4/0x150 arch/x86/kernel/stacktrace.c:24
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]
kmem_cache_free+0x197/0x620 mm/slub.c:6785
anon_vma_chain_free mm/rmap.c:146 [inline]
unlink_anon_vmas+0x2cc/0x670 mm/rmap.c:420
anon_vma_merge include/linux/rmap.h:172 [inline]
vma_complete+0x78d/0xae0 mm/vma.c:379
commit_merge+0x642/0x700 mm/vma.c:760
vma_merge_existing_range mm/vma.c:969 [inline]
vma_modify+0x1248/0x1a70 mm/vma.c:1611
vma_modify_flags+0x208/0x2e0 mm/vma.c:1654
mprotect_fixup+0x43c/0xa30 mm/mprotect.c:756
do_mprotect_pkey+0x8c5/0xcd0 mm/mprotect.c:930
__do_sys_mprotect mm/mprotect.c:951 [inline]
__se_sys_mprotect mm/mprotect.c:948 [inline]
__x64_sys_mprotect+0x80/0x90 mm/mprotect.c:948
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: 0033:0x7f5d57c53fe7
RSP: 002b:00007ffe7d811d98 EFLAGS: 00000246 ORIG_RAX: 000000000000000a
RAX: ffffffffffffffda RBX: 0000000000000200 RCX: 00007f5d57c53fe7
RDX: 0000000000000001 RSI: 0000000000000200 RDI: 00007f5d57b4d000
RBP: 00005567278b4610 R08: 0000000000000000 R09: 0000000000000200
R10: 00005567278b4670 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000001000 R14: 000055672775f638 R15: 00007f5d57df639c
rcu: rcu_preempt kthread starved for 10577 jiffies! g58117 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:26608 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:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
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: 7e6cfc3fba6c8f00 RBX: ffffffff819786ba RCX: 7e6cfc3fba6c8f00
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: 00007f77181b42f8 CR3: 0000000030bb8000 CR4: 00000000003526f0
DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000083
DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400
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