rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P12672/1:b..l
rcu: (detected by 1, t=10503 jiffies, g=50233, q=389 ncpus=2)
task:syz.1.2442 state:R running task stack:24584 pid:12672 tgid:12671 ppid:5833 task_flags:0x400140 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5396 [inline]
__schedule+0x16f5/0x4d00 kernel/sched/core.c:6785
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7108
irqentry_exit+0x6f/0x90 kernel/entry/common.c:307
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:get_current arch/x86/include/asm/current.h:25 [inline]
RIP: 0010:write_comp_data kernel/kcov.c:245 [inline]
RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x8/0x90 kernel/kcov.c:314
Code: 48 89 44 11 20 e9 93 e0 4f ff cc 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 <65> 48 8b 14 25 08 f0 9c 92 65 8b 0d 88 8f dc 10 81 e1 00 01 ff 00
RSP: 0018:ffffc9000efc6ee8 EFLAGS: 00000246
RAX: ffffffff81cf474e RBX: 0000000000000000 RCX: ffff888053d13c00
RDX: ffffc9000c6a9000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff81cf4576
R10: dffffc0000000000 R11: ffffffff81acf690 R12: 0000000000000354
R13: dffffc0000000000 R14: 00007ff48978e929 R15: 0000000000000000
rcu_read_unlock include/linux/rcupdate.h:869 [inline]
is_bpf_text_address+0x1fe/0x2b0 kernel/bpf/core.c:774
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:369
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:47 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
unpoison_slab_object mm/kasan/common.c:319 [inline]
__kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:345
kasan_slab_alloc include/linux/kasan.h:250 [inline]
slab_post_alloc_hook mm/slub.c:4148 [inline]
slab_alloc_node mm/slub.c:4197 [inline]
kmem_cache_alloc_noprof+0x1c1/0x3c0 mm/slub.c:4204
mempool_alloc_noprof+0x1a7/0x510 mm/mempool.c:402
bio_alloc_bioset+0x241/0x1110 block/bio.c:555
bio_alloc include/linux/bio.h:372 [inline]
submit_bh_wbc+0x22e/0x520 fs/buffer.c:2811
ext4_read_bh_lock+0xb2/0xd0 fs/ext4/super.c:217
ext4_bread_batch+0x232/0x4b0 fs/ext4/inode.c:1055
__ext4_find_entry+0x1082/0x1f20 fs/ext4/namei.c:1601
ext4_lookup_entry fs/ext4/namei.c:1703 [inline]
ext4_lookup+0x13d/0x6c0 fs/ext4/namei.c:1771
__lookup_slow+0x297/0x3d0 fs/namei.c:1817
lookup_slow+0x53/0x70 fs/namei.c:1834
walk_component+0x2d2/0x400 fs/namei.c:2138
lookup_last fs/namei.c:2639 [inline]
path_lookupat+0x163/0x430 fs/namei.c:2663
filename_lookup+0x212/0x570 fs/namei.c:2692
user_path_at+0x3a/0x60 fs/namei.c:3136
do_mount fs/namespace.c:4219 [inline]
__do_sys_mount fs/namespace.c:4433 [inline]
__se_sys_mount+0x2d3/0x410 fs/namespace.c:4410
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff48978e929
RSP: 002b:00007ff48a5dd038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ff4899b5fa0 RCX: 00007ff48978e929
RDX: 0000200000000180 RSI: 0000200000000140 RDI: 0000000000000000
RBP: 00007ff489810b39 R08: 00002000000011c0 R09: 0000000000000000
R10: 0000000001204001 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007ff4899b5fa0 R15: 00007ffc44a555b8
rcu: rcu_preempt kthread starved for 10501 jiffies! g50233 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:26824 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5396 [inline]
__schedule+0x16f5/0x4d00 kernel/sched/core.c:6785
__schedule_loop kernel/sched/core.c:6863 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6878
schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2054
rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2256
kthread+0x711/0x8a0 kernel/kthread.c:464
ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 UID: 0 PID: 12689 Comm: syz.5.2448 Not tainted 6.16.0-rc2-syzkaller-00231-g75f5f23f8787 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline]
RIP: 0010:smp_call_function_many_cond+0xf6e/0x12d0 kernel/smp.c:885
Code: 89 ee 83 e6 01 31 ff e8 70 78 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 1b 74 0b 00 eb 37 f3 90 43 0f b6 04 2c <84> c0 75 10 41 f7 07 01 00 00 00 74 1e e8 00 74 0b 00 eb e5 44 89
RSP: 0018:ffffc90015e7f980 EFLAGS: 00000293
RAX: 0000000000000000 RBX: ffff8880b873b1c0 RCX: ffff88801c33da00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90015e7fae0 R08: ffffffff8fa10ff7 R09: 1ffffffff1f421fe
R10: dffffc0000000000 R11: fffffbfff1f421ff R12: 1ffff110170c8385
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8880b8641c28
FS: 00005555637ca500(0000) GS:ffff888125d51000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b30118ff8 CR3: 000000007a591000 CR4: 0000000000350ef0
Call Trace:
on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1052
on_each_cpu include/linux/smp.h:71 [inline]
smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2691 [inline]
smp_text_poke_batch_finish+0x5e0/0x1100 arch/x86/kernel/alternative.c:2901
arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
static_key_disable_cpuslocked+0xc5/0x1b0 kernel/jump_label.c:240
static_key_disable+0x1a/0x20 kernel/jump_label.c:248
tracepoint_remove_func kernel/tracepoint.c:370 [inline]
tracepoint_probe_unregister+0x80e/0x9b0 kernel/tracepoint.c:504
bpf_raw_tp_link_release+0x43/0x70 kernel/bpf/syscall.c:3635
bpf_link_free+0xed/0x330 kernel/bpf/syscall.c:3157
bpf_link_put_direct kernel/bpf/syscall.c:3200 [inline]
bpf_link_release+0x6b/0x80 kernel/bpf/syscall.c:3207
__fput+0x44c/0xa70 fs/file_table.c:465
task_work_run+0x1d4/0x260 kernel/task_work.c:227
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
exit_to_user_mode_loop+0xec/0x110 kernel/entry/common.c:114
exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline]
do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f55aa58e929
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:00007ffd80b82398 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 0000000000056b47 RCX: 00007f55aa58e929
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f55aa7b7ba0 R08: 0000000000000001 R09: 0000000480b8268f
R10: 00007f55aa400000 R11: 0000000000000246 R12: 00007f55aa7b5fac
R13: 00007f55aa7b5fa0 R14: ffffffffffffffff R15: 00007ffd80b824b0