rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5188/1:b..l P15713/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=68273, q=105 ncpus=2)
task:syz.5.2348 state:R running task stack:27544 pid:15713 tgid:15709 ppid:7869 task_flags:0x40044c flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1139/0x6150 kernel/sched/core.c:6863
preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7190
irqentry_exit+0x1d8/0x8c0 kernel/entry/common.c:216
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:unwind_next_frame+0x572/0x20b0 arch/x86/kernel/unwind_orc.c:527
Code: c1 ee 03 48 c1 ea 03 0f b6 14 02 0f b6 04 06 4c 89 c6 83 e6 07 40 38 f2 40 0f 9e c6 84 d2 0f 95 c2 40 84 d6 0f 85 ae 14 00 00 <41> 83 e7 07 44 38 f8 0f 9e c2 84 c0 0f 95 c0 84 c2 0f 85 97 14 00
RSP: 0018:ffffc9000ed57518 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff912245ba
RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffffffff909e6fd8
RBP: ffffc9000ed575d0 R08: ffffffff912245be R09: 000000002d64dbdc
R10: 0000000000000002 R11: 000000000000810b R12: ffffc9000ed575d8
R13: ffffc9000ed57588 R14: ffffc9000ed575bd R15: ffffffff912245bf
arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
kasan_save_stack+0x33/0x60 mm/kasan/common.c:57
kasan_save_track+0x14/0x30 mm/kasan/common.c:78
poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
__kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:415
kmalloc_noprof include/linux/slab.h:957 [inline]
slab_free_hook mm/slub.c:2492 [inline]
slab_free mm/slub.c:6670 [inline]
kmem_cache_free+0x147/0x770 mm/slub.c:6781
exit_mmap+0x507/0xb60 mm/mmap.c:1302
__mmput+0x12a/0x410 kernel/fork.c:1173
mmput+0x62/0x70 kernel/fork.c:1196
exit_mm kernel/exit.c:581 [inline]
do_exit+0x7d7/0x2bd0 kernel/exit.c:959
do_group_exit+0xd3/0x2a0 kernel/exit.c:1112
get_signal+0x2671/0x26d0 kernel/signal.c:3034
arch_do_signal_or_restart+0x8f/0x7e0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:41 [inline]
exit_to_user_mode_loop+0x8c/0x540 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+0x4ee/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fdd7f38f749
RSP: 002b:00007fdd801cb0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: 0000000000000000 RBX: 00007fdd7f5e6188 RCX: 00007fdd7f38f749
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fdd7f5e6188
RBP: 00007fdd7f5e6180 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fdd7f5e6218 R14: 00007fffd975f2e0 R15: 00007fffd975f3c8
task:udevd state:R running task stack:23608 pid:5188 tgid:5188 ppid:1 task_flags:0x400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1139/0x6150 kernel/sched/core.c:6863
preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7190
irqentry_exit+0x1d8/0x8c0 kernel/entry/common.c:216
asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:rcu_read_lock include/linux/rcupdate.h:868 [inline]
RIP: 0010:__page_table_check_zero+0x362/0x4a0 mm/page_table_check.c:138
Code: e9 69 ff ff ff e8 ae cf 89 ff 90 0f 0b e8 a6 cf 89 ff 90 0f 0b e8 9e cf 89 ff e8 89 f8 6d ff 31 ff 89 c5 89 c6 e8 ce c9 89 ff <40> 84 ed 0f 85 97 fd ff ff e8 80 cf 89 ff e8 eb 1d 43 09 31 ff 89
RSP: 0018:ffffc900035a7a78 EFLAGS: 00000293
RAX: 0000000000000000 RBX: ffffea0000db1e00 RCX: ffffffff82351962
RDX: ffff88807bbac980 RSI: 0000000000000000 RDI: 0000000000000001
RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: ffff88807bbad4b0 R12: ffffffff8dd74560
R13: ffffea0000db1e00 R14: 0000000000000003 R15: 0000000000000000
page_table_check_free include/linux/page_table_check.h:43 [inline]
free_pages_prepare mm/page_alloc.c:1407 [inline]
__free_frozen_pages+0x7d0/0x1170 mm/page_alloc.c:2943
discard_slab mm/slub.c:3346 [inline]
__put_partials+0x130/0x170 mm/slub.c:3886
qlink_free mm/kasan/quarantine.c:163 [inline]
qlist_free_all+0x4c/0xf0 mm/kasan/quarantine.c:179
kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286
__kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:350
kasan_slab_alloc include/linux/kasan.h:253 [inline]
slab_post_alloc_hook mm/slub.c:4953 [inline]
slab_alloc_node mm/slub.c:5263 [inline]
kmem_cache_alloc_noprof+0x25e/0x770 mm/slub.c:5270
getname_flags.part.0+0x4c/0x550 fs/namei.c:146
getname_flags+0x93/0xf0 include/linux/audit.h:345
getname include/linux/fs.h:2498 [inline]
getname_maybe_null include/linux/fs.h:2505 [inline]
getname_maybe_null include/linux/fs.h:2502 [inline]
vfs_fstatat+0xe1/0xf0 fs/stat.c:370
__do_sys_newfstatat+0x97/0x120 fs/stat.c:542
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6bead11b0a
RSP: 002b:00007fffbd4a2208 EFLAGS: 00000246 ORIG_RAX: 0000000000000106
RAX: ffffffffffffffda RBX: 0000563b33e62400 RCX: 00007f6bead11b0a
RDX: 00007fffbd4a2210 RSI: 0000563b33e50296 RDI: 00000000ffffff9c
RBP: 0000563b71c23668 R08: 0000000033457ba7 R09: 00007f6beb516000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007fffbd4a2210 R14: 0000000000000000 R15: 0000000000000000
rcu: rcu_preempt kthread starved for 10337 jiffies! g68273 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:27144 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1139/0x6150 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:6960
schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1ea/0xaf0 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x26d/0x380 kernel/rcu/tree.c:2285
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x983/0xb10 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:
CPU: 0 UID: 0 PID: 0 Comm: swapper/0 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:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82
Code: a6 5f 02 c3 cc cc cc cc 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 13 19 12 00 fb f4 cc 35 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffffff8e007df8 EFLAGS: 000002c6
RAX: 00000000041714e7 RBX: 0000000000000000 RCX: ffffffff8b7846d9
RDX: 0000000000000000 RSI: ffffffff8dacea71 RDI: ffffffff8bf2b400
RBP: fffffbfff1c12f68 R08: 0000000000000001 R09: ffffed101708673d
R10: ffff8880b84339eb R11: ffffffff8e098670 R12: 0000000000000000
R13: ffffffff8e097b40 R14: ffffffff9088b9d0 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8881248f5000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000076697000 CR4: 00000000003526f0
Call Trace:
arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:767
default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:191 [inline]
do_idle+0x38d/0x510 kernel/sched/idle.c:332
cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:430
rest_init+0x16b/0x2b0 init/main.c:757
start_kernel+0x3ef/0x4d0 init/main.c:1206
x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:310
x86_64_start_kernel+0x130/0x190 arch/x86/kernel/head64.c:291
common_startup_64+0x13e/0x148