rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P7724/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=20829, q=281 ncpus=2)
task:syz.1.424 state:R running task stack:23856 pid:7724 tgid:7721 ppid:5831 task_flags:0x400140 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x1b9a/0x5250 kernel/sched/core.c:6769
preempt_schedule_irq+0xfe/0x1c0 kernel/sched/core.c:7092
irqentry_exit+0x5e/0x90 kernel/entry/common.c:354
asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:707
RIP: 0010:lock_acquire+0x167/0x2f0 arch/x86/include/asm/irqflags.h:-1
Code: c7 44 24 10 00 00 00 00 9c 8f 44 24 10 f7 44 24 10 00 02 00 00 0f 85 fd 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 65 48 8b 45 00 <48> 3b 44 24 38 0f 85 72 01 00 00 48 83 c4 40 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc9000b28e888 EFLAGS: 00000206
RAX: 1a659f3f244bd500 RBX: ffffffff8ed3f180 RCX: 1a659f3f244bd500
RDX: 0000000000000000 RSI: ffffffff8e50b292 RDI: ffffffff8ca1ee40
RBP: ffffffff936a0020 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000002 R14: 0000000000000246 R15: 0000000000000000
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:841 [inline]
class_rcu_constructor include/linux/rcupdate.h:1155 [inline]
unwind_next_frame+0xd5/0x23b0 arch/x86/kernel/unwind_orc.c:479
arch_stack_walk+0x11e/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x11a/0x1d0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
unpoison_slab_object mm/kasan/common.c:319 [inline]
__kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:345
kasan_slab_alloc include/linux/kasan.h:250 [inline]
slab_post_alloc_hook mm/slub.c:4151 [inline]
slab_alloc_node mm/slub.c:4200 [inline]
kmem_cache_alloc_noprof+0x1e1/0x390 mm/slub.c:4207
__kernfs_new_node+0xdf/0x890 fs/kernfs/dir.c:637
kernfs_new_node+0x114/0x220 fs/kernfs/dir.c:713
__kernfs_create_file+0x49/0x2e0 fs/kernfs/file.c:1038
sysfs_add_file_mode_ns+0x24a/0x310 fs/sysfs/file.c:319
create_files fs/sysfs/group.c:76 [inline]
internal_create_group+0x7ea/0x1320 fs/sysfs/group.c:183
internal_create_groups fs/sysfs/group.c:223 [inline]
sysfs_create_groups+0x56/0x120 fs/sysfs/group.c:249
create_dir lib/kobject.c:78 [inline]
kobject_add_internal+0x472/0x8d0 lib/kobject.c:240
kobject_add_varg lib/kobject.c:374 [inline]
kobject_add+0x15b/0x230 lib/kobject.c:426
bch2_fs_online+0x1fc/0x580 fs/bcachefs/super.c:732
bch2_fs_alloc fs/bcachefs/super.c:1012 [inline]
bch2_fs_open+0x3069/0x30d0 fs/bcachefs/super.c:2248
bch2_fs_get_tree+0x775/0x18e0 fs/bcachefs/fs.c:2172
vfs_get_tree+0x90/0x2b0 fs/super.c:1809
do_new_mount+0x2cf/0xb70 fs/namespace.c:3879
do_mount fs/namespace.c:4219 [inline]
__do_sys_mount fs/namespace.c:4430 [inline]
__se_sys_mount+0x38c/0x400 fs/namespace.c:4407
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fefee58f90a
RSP: 002b:00007fefef37de68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fefef37def0 RCX: 00007fefee58f90a
RDX: 0000200000000080 RSI: 0000200000000340 RDI: 00007fefef37deb0
RBP: 0000200000000080 R08: 00007fefef37def0 R09: 0000000000800010
R10: 0000000000800010 R11: 0000000000000246 R12: 0000200000000340
R13: 00007fefef37deb0 R14: 0000000000005981 R15: 00002000000001c0
rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g20829 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: Possible timer handling issue on cpu=1 timer-softirq=14565
rcu: rcu_preempt kthread starved for 10502 jiffies! g20829 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:26952 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x1b9a/0x5250 kernel/sched/core.c:6769
__schedule_loop kernel/sched/core.c:6847 [inline]
schedule+0x163/0x360 kernel/sched/core.c:6862
schedule_timeout+0x15b/0x2b0 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x2e1/0x1340 kernel/rcu/tree.c:2024
rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2226
kthread+0x7b7/0x940 kernel/kthread.c:464
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 7304 Comm: udevd Not tainted 6.15.0-rc1-next-20250411-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:__sanitizer_cov_trace_const_cmp1+0x0/0x90 kernel/kcov.c:299
Code: 11 18 4c 89 44 11 20 c3 cc cc cc cc 66 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 4c 8b 04 24 65 48 8b 14 25 08 00 6a 93 65 8b 05 d8 82
RSP: 0018:ffffc90000a08d38 EFLAGS: 00000046
RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffff88802b883c00
RDX: ffff88807bc95378 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90000a08ea0 R08: ffffffff81b0ed83 R09: 1ffffffff20c0836
R10: dffffc0000000000 R11: fffffbfff20c0837 R12: 1ffff110170e4f83
R13: dffffc0000000000 R14: ffff88807bc95340 R15: ffff8880b8727ac0
FS: 00007f33e72a8c80(0000) GS:ffff888125080000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b3100ce00 CR3: 000000002fb90000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
__remove_hrtimer kernel/time/hrtimer.c:1118 [inline]
__run_hrtimer kernel/time/hrtimer.c:1741 [inline]
__hrtimer_run_queues+0x3bd/0xd40 kernel/time/hrtimer.c:1825
hrtimer_interrupt+0x403/0xa40 kernel/time/hrtimer.c:1887
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline]
__sysvec_apic_timer_interrupt+0x110/0x420 arch/x86/kernel/apic/apic.c:1055
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1049
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_release+0x23/0x3e0 kernel/locking/lockdep.c:5874
Code: 90 90 90 90 90 90 90 f3 0f 1e fa 55 41 57 41 56 41 55 41 54 53 48 83 ec 30 48 89 f5 49 89 ff 48 c7 c3 20 00 6a 93 65 48 8b 03 <48> 89 44 24 28 0f 1f 44 00 00 65 8b 05 10 df ca 11 83 f8 08 0f 83
RSP: 0018:ffffc9000c5ef320 EFLAGS: 00000282
RAX: 90a57b9b7bf2aa00 RBX: ffffffff936a0020 RCX: ffff88802b883c00
RDX: dffffc0000000000 RSI: ffffffff816e6268 RDI: ffffffff8ed3f180
RBP: ffffffff816e6268 R08: ffffc9000c5ef8e8 R09: 0000000000000000
R10: ffffc9000c5ef4b0 R11: fffff520018bde98 R12: ffffc9000c5ef470
R13: dffffc0000000000 R14: ffffc9000c5ef8f8 R15: ffffffff8ed3f180
rcu_lock_release include/linux/rcupdate.h:341 [inline]
rcu_read_unlock include/linux/rcupdate.h:871 [inline]
class_rcu_destructor include/linux/rcupdate.h:1155 [inline]
unwind_next_frame+0x1a9f/0x23b0 arch/x86/kernel/unwind_orc.c:680
arch_stack_walk+0x11e/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x11a/0x1d0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
unpoison_slab_object mm/kasan/common.c:319 [inline]
__kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:345
kasan_slab_alloc include/linux/kasan.h:250 [inline]
slab_post_alloc_hook mm/slub.c:4151 [inline]
slab_alloc_node mm/slub.c:4200 [inline]
kmem_cache_alloc_noprof+0x1e1/0x390 mm/slub.c:4207
lsm_file_alloc security/security.c:733 [inline]
security_file_alloc+0x32/0x310 security/security.c:2858
init_file+0x90/0x300 fs/file_table.c:156
alloc_empty_file+0x70/0x1d0 fs/file_table.c:238
path_openat+0x10d/0x35d0 fs/namei.c:3994
do_filp_open+0x284/0x4e0 fs/namei.c:4035
do_sys_openat2+0x12b/0x1d0 fs/open.c:1429
do_sys_open fs/open.c:1444 [inline]
__do_sys_openat fs/open.c:1460 [inline]
__se_sys_openat fs/open.c:1455 [inline]
__x64_sys_openat+0x249/0x2a0 fs/open.c:1455
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f33e737e9a4
Code: 24 20 48 8d 44 24 30 48 89 44 24 28 64 8b 04 25 18 00 00 00 85 c0 75 2c 44 89 e2 48 89 ee bf 9c ff ff ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 76 60 48 8b 15 55 a4 0d 00 f7 d8 64 89 02 48 83
RSP: 002b:00007ffec2c4fa30 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000000008 RCX: 00007f33e737e9a4
RDX: 0000000000080000 RSI: 00007ffec2c4fb68 RDI: 00000000ffffff9c
RBP: 00007ffec2c4fb68 R08: 0000000000000008 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000080000
R13: 0000564e5806ab42 R14: 0000000000000001 R15: 0000564e58086160