rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P15/2:b..l P5612/5:b..l
rcu: (detected by 1, t=10502 jiffies, g=51433, q=342 ncpus=2)
task:syz-executor state:R running task stack:21328 pid:5612 tgid:5612 ppid:5607 task_flags:0x400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5510 [inline]
__schedule+0x1709/0x5530 kernel/sched/core.c:7234
preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7556
irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline]
irqentry_exit+0x14f/0x8f0 kernel/entry/common.c:167
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:lock_acquire+0x221/0x350 kernel/locking/lockdep.c:5874
Code: ff ff ff e8 d1 29 8f 09 f7 44 24 08 00 02 00 00 0f 84 3a ff ff ff 65 48 8b 05 9b 24 d4 10 48 3b 44 24 58 75 33 fb 48 83 c4 60 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 c0 f2 92 09 cc 48 8d 3d b8 34 ef
RSP: 0018:ffffc90004877288 EFLAGS: 00000286
RAX: 639d293cb8213a00 RBX: 0000000000000000 RCX: 0000000000000046
RDX: 00000000f8fde191 RSI: ffffffff8d8bc64f RDI: ffffffff8baa5580
RBP: ffffffff823814f6 R08: ffffffff823814f6 R09: 0000000000000000
R10: 0000000000000000 R11: ffffffff8dfc3040 R12: 0000000000000002
R13: ffffffff8dfc3040 R14: 0000000000000000 R15: 0000000000000246
rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
rcu_read_lock include/linux/rcupdate.h:840 [inline]
page_table_check_set+0x143/0x510 mm/page_table_check.c:112
page_table_check_ptes_set include/linux/page_table_check.h:83 [inline]
set_ptes include/linux/pgtable.h:447 [inline]
__copy_present_ptes mm/memory.c:1118 [inline]
copy_present_ptes mm/memory.c:1197 [inline]
copy_pte_range mm/memory.c:1320 [inline]
copy_pmd_range+0x33b5/0x53e0 mm/memory.c:1408
copy_pud_range mm/memory.c:1445 [inline]
copy_p4d_range mm/memory.c:1469 [inline]
copy_page_range+0xb34/0x1160 mm/memory.c:1555
dup_mmap+0xf2d/0x1d40 mm/mmap.c:1840
dup_mm kernel/fork.c:1538 [inline]
copy_mm+0x11a/0x480 kernel/fork.c:1590
copy_process+0x1ea1/0x43f0 kernel/fork.c:2288
kernel_clone+0x2d7/0x940 kernel/fork.c:2747
__do_sys_clone kernel/fork.c:2888 [inline]
__se_sys_clone kernel/fork.c:2872 [inline]
__x64_sys_clone+0x1b6/0x230 kernel/fork.c:2872
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb6e78658d2
RSP: 002b:00007ffdb457c550 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007ffdb457c550 RCX: 00007fb6e78658d2
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 00007ffdb457c6dc R08: 0000000000000000 R09: 0000000000000001
R10: 00005555663347d0 R11: 0000000000000246 R12: 0000000000000001
R13: 0000555566347a10 R14: 00000000000d63b1 R15: 00007ffdb457c730
task:ksoftirqd/0 state:R running task stack:24624 pid:15 tgid:15 ppid:2 task_flags:0x4208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5510 [inline]
__schedule+0x1709/0x5530 kernel/sched/core.c:7234
preempt_schedule_notrace+0x57/0x90 kernel/sched/core.c:7506
preempt_schedule_notrace_thunk+0x16/0x30 arch/x86/entry/thunk.S:13
rcu_is_watching+0x7f/0xb0 kernel/rcu/tree.c:753
rcu_read_unlock include/linux/rcupdate.h:869 [inline]
sched_balance_domains+0x725/0x880 kernel/sched/fair.c:13825
handle_softirqs+0x1d9/0x6c0 kernel/softirq.c:626
run_ksoftirqd+0x52/0x180 kernel/softirq.c:1080
smpboot_thread_fn+0x57c/0xa80 kernel/smpboot.c:160
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
rcu: rcu_preempt kthread timer wakeup didn't happen for 10447 jiffies! g51433 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: Possible timer handling issue on cpu=1 timer-softirq=47559
rcu: rcu_preempt kthread starved for 10448 jiffies! g51433 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:24336 pid:18 tgid:18 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5510 [inline]
__schedule+0x1709/0x5530 kernel/sched/core.c:7234
__schedule_loop kernel/sched/core.c:7311 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7326
schedule_timeout+0x152/0x2c0 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x30c/0x11c0 kernel/rcu/tree.c:2123
rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2325
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
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: 12178 Comm: syz.4.1513 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)}
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:preempt_count_add+0x0/0x190 kernel/sched/core.c:5972
Code: be e0 0e 00 00 e8 20 7e 9d 00 e9 70 ff ff ff e9 d3 fe ff ff 66 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 41 57 41 56 53 49 bf 00 00 00 00 00 fc ff df 48 c7 c0
RSP: 0018:ffffc90004be7ad0 EFLAGS: 00000286
RAX: 0000000080000000 RBX: 00000000000055f2 RCX: 0000000000000000
RDX: 00000000000001ff RSI: ffffffff8baa5560 RDI: 0000000000000001
RBP: 0000000000000001 R08: ffffffff8f8c6cf7 R09: 1ffffffff1f18d9e
R10: dffffc0000000000 R11: ffffffff8b2e5c40 R12: ffff8880600d1e00
R13: ffff8880600d1e10 R14: 000001ff286052fe R15: 0000000000004c14
FS: 0000555562b26500(0000) GS:ffff888125fd4000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe4dfbfd710 CR3: 000000003a528000 CR4: 00000000003526f0
DR0: ffffffffffffffff DR1: 00000000000001f7 DR2: 00000000ffffffff
DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
delay_tsc+0x65/0xc0 arch/x86/lib/delay.c:79
udelay include/asm-generic/delay.h:62 [inline]
snd_timer_close_locked+0x435/0xbd0 sound/core/timer.c:497
snd_timer_close+0x44/0xc0 sound/core/timer.c:529
snd_seq_timer_close+0x8a/0xc0 sound/core/seq/seq_timer.c:311
queue_delete sound/core/seq/seq_queue.c:126 [inline]
snd_seq_queue_delete+0x8d/0xf0 sound/core/seq/seq_queue.c:188
delete_seq_queue sound/core/seq/oss/seq_oss_init.c:371 [inline]
snd_seq_oss_release+0x1e9/0x330 sound/core/seq/oss/seq_oss_init.c:416
odev_release+0x56/0x80 sound/core/seq/oss/seq_oss.c:141
__fput+0x42a/0xa80 fs/file_table.c:512
task_work_run+0x1d9/0x270 kernel/task_work.c:233
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
__exit_to_user_mode_loop kernel/entry/common.c:70 [inline]
exit_to_user_mode_loop+0x1fa/0x730 kernel/entry/common.c:101
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
do_syscall_64+0x353/0x580 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f974b75ce59
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fffbd963968 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007f974b9d7da0 RCX: 00007f974b75ce59
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f974b9d7da0 R08: 0000000000000006 R09: 0000000000000000
R10: 00007f974b9d7cb0 R11: 0000000000000246 R12: 00000000000d762d
R13: 00007f974b9d618c R14: 00000000000d74a8 R15: 00007f974b9d6180
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 12178 Comm: syz.4.1513 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)}
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:preempt_count_add+0x0/0x190 kernel/sched/core.c:5972
Code: be e0 0e 00 00 e8 20 7e 9d 00 e9 70 ff ff ff e9 d3 fe ff ff 66 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 41 57 41 56 53 49 bf 00 00 00 00 00 fc ff df 48 c7 c0
RSP: 0018:ffffc90004be7ad0 EFLAGS: 00000286
RAX: 0000000080000000 RBX: 00000000000055f2 RCX: 0000000000000000
RDX: 0000000000000219 RSI: ffffffff8baa5560 RDI: 0000000000000001
RBP: 0000000000000001 R08: ffffffff8f8c6cf7 R09: 1ffffffff1f18d9e
R10: dffffc0000000000 R11: ffffffff8b2e5c40 R12: ffff8880600d1e00
R13: ffff8880600d1e10 R14: 00000219dc0db922 R15: 00000000000035e4
FS: 0000555562b26500(0000) GS:ffff888125fd4000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe4dfbfd710 CR3: 000000003a528000 CR4: 00000000003526f0
DR0: ffffffffffffffff DR1: 00000000000001f7 DR2: 00000000ffffffff
DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
delay_tsc+0x65/0xc0 arch/x86/lib/delay.c:79
udelay include/asm-generic/delay.h:62 [inline]
snd_timer_close_locked+0x435/0xbd0 sound/core/timer.c:497
snd_timer_close+0x44/0xc0 sound/core/timer.c:529
snd_seq_timer_close+0x8a/0xc0 sound/core/seq/seq_timer.c:311
queue_delete sound/core/seq/seq_queue.c:126 [inline]
snd_seq_queue_delete+0x8d/0xf0 sound/core/seq/seq_queue.c:188
delete_seq_queue sound/core/seq/oss/seq_oss_init.c:371 [inline]
snd_seq_oss_release+0x1e9/0x330 sound/core/seq/oss/seq_oss_init.c:416
odev_release+0x56/0x80 sound/core/seq/oss/seq_oss.c:141
__fput+0x42a/0xa80 fs/file_table.c:512
task_work_run+0x1d9/0x270 kernel/task_work.c:233
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
__exit_to_user_mode_loop kernel/entry/common.c:70 [inline]
exit_to_user_mode_loop+0x1fa/0x730 kernel/entry/common.c:101
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
do_syscall_64+0x353/0x580 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f974b75ce59
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fffbd963968 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007f974b9d7da0 RCX: 00007f974b75ce59
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f974b9d7da0 R08: 0000000000000006 R09: 0000000000000000
R10: 00007f974b9d7cb0 R11: 0000000000000246 R12: 00000000000d762d
R13: 00007f974b9d618c R14: 00000000000d74a8 R15: 00007f974b9d6180