rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5838/1:b..l P8926/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=30445, q=298 ncpus=2)
task:syz.5.627 state:R running task stack:25112 pid:8926 tgid:8923 ppid:7723 task_flags:0x400040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5260 [inline]
__schedule+0x14ea/0x5050 kernel/sched/core.c:6867
preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7194
irqentry_exit+0x597/0x620 kernel/entry/common.c:216
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_acquire+0x221/0x330 kernel/locking/lockdep.c:5872
Code: ff ff ff e8 41 b0 f6 09 f7 44 24 08 00 02 00 00 0f 84 3a ff ff ff 65 48 8b 05 2b 61 52 11 48 3b 44 24 58 75 33 fb 48 83 c4 60 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 fb f1 6f ff cc 48 8d 3d 38 12 52
RSP: 0018:ffffc9000e9978c0 EFLAGS: 00000286
RAX: 5f00d722cfc35f00 RBX: 0000000000000000 RCX: 0000000000000046
RDX: 000000006cc10c15 RSI: ffffffff8df34258 RDI: ffffffff8c073980
RBP: ffffffff81fe397a R08: ffffffff81fe397a R09: ffffffff8e55a360
R10: dffffc0000000000 R11: fffff52001d32f2b R12: 0000000000000002
R13: ffffffff8e55a360 R14: 0000000000000000 R15: 0000000000000246
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:867 [inline]
filemap_get_entry+0xe6/0x320 mm/filemap.c:1892
shmem_get_folio_gfp+0x243/0x1670 mm/shmem.c:2480
shmem_get_folio mm/shmem.c:2662 [inline]
shmem_write_begin+0x16c/0x330 mm/shmem.c:3315
generic_perform_write+0x2e2/0x8f0 mm/filemap.c:4314
shmem_file_write_iter+0xf8/0x120 mm/shmem.c:3490
new_sync_write fs/read_write.c:593 [inline]
vfs_write+0x61d/0xb90 fs/read_write.c:686
ksys_write+0x150/0x270 fs/read_write.c:738
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ffa1f15b78e
RSP: 002b:00007ffa2008eda8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007ffa2008f6c0 RCX: 00007ffa1f15b78e
RDX: 0000000001000000 RSI: 00007ffa14e00000 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003
R13: 00007ffa2008eee0 R14: 00007ffa2008eea0 R15: 00007ffa14e00000
task:udevd state:R running task stack:23288 pid:5838 tgid:5838 ppid:5188 task_flags:0x400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5260 [inline]
__schedule+0x14ea/0x5050 kernel/sched/core.c:6867
preempt_schedule_notrace+0x57/0x90 kernel/sched/core.c:7144
preempt_schedule_notrace_thunk+0x16/0x30 arch/x86/entry/thunk.S:13
rcu_is_watching+0x7f/0xb0 kernel/rcu/tree.c:752
rcu_read_unlock include/linux/rcupdate.h:895 [inline]
class_rcu_destructor include/linux/rcupdate.h:1195 [inline]
unwind_next_frame+0x1a66/0x23c0 arch/x86/kernel/unwind_orc.c:695
arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xa9/0x100 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+0x195/0x610 mm/slub.c:6785
do_renameat2+0x879/0x900 fs/namei.c:6078
__do_sys_rename fs/namei.c:6099 [inline]
__se_sys_rename fs/namei.c:6097 [inline]
__x64_sys_rename+0x82/0x90 fs/namei.c:6097
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fafdb39acc7
RSP: 002b:00007ffe28353e88 EFLAGS: 00000202 ORIG_RAX: 0000000000000052
RAX: ffffffffffffffda RBX: 000056098d9707a0 RCX: 00007fafdb39acc7
RDX: 000056098d953010 RSI: 00007ffe28353ea0 RDI: 00007ffe283542a0
RBP: 000056098d95b650 R08: 00000000000001e0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00007ffe28353ea0
R13: 00007ffe283542a0 R14: 0000000000000000 R15: 000056098d968b10
rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g30445 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: Possible timer handling issue on cpu=0 timer-softirq=23029
rcu: rcu_preempt kthread starved for 10502 jiffies! g30445 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:28080 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5260 [inline]
__schedule+0x14ea/0x5050 kernel/sched/core.c:6867
__schedule_loop kernel/sched/core.c:6949 [inline]
schedule+0x164/0x360 kernel/sched/core.c:6964
schedule_timeout+0x158/0x2c0 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x312/0x1560 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x9d/0x3b0 kernel/rcu/tree.c:2285
kthread+0x726/0x8b0 kernel/kthread.c:463
ret_from_fork+0x51b/0xa40 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: 8906 Comm: syz.7.621 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:get_current arch/x86/include/asm/current.h:25 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x8/0x70 kernel/kcov.c:216
Code: 8b 3d c4 2e 33 0c 48 89 de 5b e9 73 c2 5c 00 cc cc cc 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 0d a8 38 2e 11 65 8b 15 c9 38 2e 11 81 e2 00 01 ff 00 74
RSP: 0018:ffffc9000b58fc88 EFLAGS: 00000046
RAX: ffffffff84f01494 RBX: 1ffff11003fdb214 RCX: 0000000000000000
RDX: ffff88802da68000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffff88801fed9080 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff520016b1f88 R12: ffff8881426a0000
R13: dffffc0000000000 R14: ffff88801fed9080 R15: 0000000000000001
FS: 000055558d4b2500(0000) GS:ffff8881256f5000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb6309e8600 CR3: 0000000033a57000 CR4: 0000000000350ef0
Call Trace:
__vga_put+0x84/0x600 drivers/pci/vgaarb.c:368
vga_put drivers/pci/vgaarb.c:551 [inline]
vga_arb_release+0x269/0x5d0 drivers/pci/vgaarb.c:1425
__fput+0x44f/0xa70 fs/file_table.c:468
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:44 [inline]
exit_to_user_mode_loop+0xed/0x480 kernel/entry/common.c:75
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
do_syscall_64+0x2b7/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb63099aeb9
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:00007ffc65a701d8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007fb630c17da0 RCX: 00007fb63099aeb9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007fb630c17da0 R08: 00007fb630c16128 R09: 0000000000000000
R10: 000000000003fd40 R11: 0000000000000246 R12: 0000000000052cb1
R13: 00007fb630c15fac R14: 0000000000052c7f R15: 00007fb630c15fa0