rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P8405/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=30117, q=1189 ncpus=2)
task:syz.1.712 state:R running task stack:26888 pid:8405 tgid:8393 ppid:5836 task_flags:0x40044c flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5401 [inline]
__schedule+0x16a2/0x4cb0 kernel/sched/core.c:6790
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7113
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:deref_stack_reg+0x13/0x230 arch/x86/kernel/unwind_orc.c:402
Code: 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 55 41 57 41 56 41 55 41 54 53 48 83 ec 20 48 89 54 24 18 <49> 89 f0 49 89 ff 48 be 00 00 00 00 00 fc ff df 48 8d 5f 08 49 89
RSP: 0018:ffffc9001ce9f300 EFLAGS: 00000286
RAX: fffffffffffffff0 RBX: ffffffff9030a93c RCX: 0000000000000000
RDX: ffffc9001ce9f468 RSI: ffffc9001ce9fad0 RDI: ffffc9001ce9f428
RBP: dffffc0000000000 R08: ffffc9001ce9f487 R09: 0000000000000000
R10: ffffc9001ce9f478 R11: fffff520039d3e91 R12: ffffc9001ce9fad0
R13: ffffc9001ce9f478 R14: ffffc9001ce9f428 R15: 1ffffffff2061527
unwind_next_frame+0x17c4/0x2390 arch/x86/kernel/unwind_orc.c:-1
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
kasan_save_stack+0x3e/0x60 mm/kasan/common.c:47
kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:548
slab_free_hook mm/slub.c:2342 [inline]
slab_free mm/slub.c:4643 [inline]
kmem_cache_free+0x2f6/0x400 mm/slub.c:4745
exit_mmap+0x53f/0xb50 mm/mmap.c:1309
__mmput+0x118/0x410 kernel/fork.c:1121
exit_mm+0x1da/0x2c0 kernel/exit.c:581
do_exit+0x648/0x22e0 kernel/exit.c:952
do_group_exit+0x21c/0x2d0 kernel/exit.c:1105
get_signal+0x125e/0x1310 kernel/signal.c:3034
arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop+0x75/0x110 kernel/entry/common.c:111
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: 0033:0x7f231738e929
RSP: 002b:00007f23181b40e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007f23175b6088 RCX: 00007f231738e929
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f23175b6088
RBP: 00007f23175b6080 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f23175b608c
R13: 0000000000000000 R14: 00007ffee9487de0 R15: 00007ffee9487ec8
rcu: rcu_preempt kthread starved for 10495 jiffies! g30117 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:27128 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5401 [inline]
__schedule+0x16a2/0x4cb0 kernel/sched/core.c:6790
__schedule_loop kernel/sched/core.c:6868 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6883
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: 0 UID: 0 PID: 8414 Comm: syz.4.718 Not tainted 6.16.0-rc5-syzkaller #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+0xf69/0x12d0 kernel/smp.c:885
Code: 00 45 8b 2f 44 89 ee 83 e6 01 31 ff e8 c0 78 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 6b 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 50 74 0b
RSP: 0018:ffffc9001cbafb00 EFLAGS: 00000293
RAX: ffffffff81b4b090 RBX: ffff8880b863b040 RCX: ffff888025da1e00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc9001cbafc58 R08: ffffffff8fa0bbf7 R09: 1ffffffff1f4177e
R10: dffffc0000000000 R11: fffffbfff1f4177f R12: 1ffff110170e7f2d
R13: dffffc0000000000 R14: 0000000000000001 R15: ffff8880b873f968
FS: 0000555591b86500(0000) GS:ffff888125c51000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b30c09ff8 CR3: 0000000033854000 CR4: 00000000003526f0
Call Trace:
on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1052
kill_bdev block/bdev.c:90 [inline]
blkdev_flush_mapping+0xfe/0x270 block/bdev.c:712
blkdev_put_whole block/bdev.c:719 [inline]
bdev_release+0x417/0x650 block/bdev.c:1144
blkdev_release+0x15/0x20 block/fops.c:684
__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: 0033:0x7f4825b8e929
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:00007ffedbb10798 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007f4825db7ba0 RCX: 00007f4825b8e929
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f4825db7ba0 R08: 0000000000015d4c R09: 0000001edbb10a8f
R10: 00007f4825db7ac0 R11: 0000000000000246 R12: 0000000000054c9a
R13: 00007ffedbb10890 R14: ffffffffffffffff R15: 00007ffedbb108b0