rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P7507/1:b..l P5208/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=21625, q=3371 ncpus=2)
task:udevd state:R running task stack:22952 pid:5208 tgid:5208 ppid:1 task_flags:0x400140 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5351 [inline]
__schedule+0x1737/0x4d30 kernel/sched/core.c:6954
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7281
irqentry_exit+0x6f/0x90 kernel/entry/common.c:196
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:on_stack arch/x86/include/asm/stacktrace.h:-1 [inline]
RIP: 0010:unwind_next_frame+0x184d/0x2390 arch/x86/kernel/unwind_orc.c:665
Code: 3c 28 00 74 05 e8 63 f3 af 00 4d 8b 6e 08 4d 8d 7e 10 4c 89 f8 48 c1 e8 03 80 3c 28 00 74 08 4c 89 ff e8 46 f3 af 00 49 8b 07 <4d> 39 e5 0f 96 c1 4c 39 e0 0f 97 c2 20 ca 80 fa 01 0f 85 63 01 00
RSP: 0018:ffffc900032276b8 EFLAGS: 00000246
RAX: ffffc90003228000 RBX: ffffffff903c2101 RCX: 0000000000000001
RDX: ffffc900032277c8 RSI: dffffc0000000000 RDI: ffffc90003227790
RBP: dffffc0000000000 R08: ffffc90003227cb8 R09: 0000000000000000
R10: ffffc900032277d8 R11: fffff52000644efd R12: ffffc90003227cc8
R13: ffffc90003220000 R14: ffffc90003227788 R15: ffffc90003227798
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
save_stack+0xf5/0x1f0 mm/page_owner.c:156
__reset_page_owner+0x71/0x1f0 mm/page_owner.c:308
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1248 [inline]
__free_frozen_pages+0xc71/0xe70 mm/page_alloc.c:2706
discard_slab mm/slub.c:2752 [inline]
__put_partials+0x156/0x1a0 mm/slub.c:3217
put_cpu_partial+0x17c/0x250 mm/slub.c:3292
__slab_free+0x2d5/0x3c0 mm/slub.c:4549
qlink_free mm/kasan/quarantine.c:163 [inline]
qlist_free_all+0x97/0x140 mm/kasan/quarantine.c:179
kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
__kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:329
kasan_slab_alloc include/linux/kasan.h:250 [inline]
slab_post_alloc_hook mm/slub.c:4179 [inline]
slab_alloc_node mm/slub.c:4228 [inline]
kmem_cache_alloc_noprof+0x1c1/0x3c0 mm/slub.c:4235
getname_flags+0xb8/0x540 fs/namei.c:146
getname include/linux/fs.h:2916 [inline]
getname_maybe_null include/linux/fs.h:2923 [inline]
vfs_fstatat+0x43/0x170 fs/stat.c:370
__do_sys_newfstatat fs/stat.c:542 [inline]
__se_sys_newfstatat fs/stat.c:536 [inline]
__x64_sys_newfstatat+0x116/0x190 fs/stat.c:536
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f98bd711b0a
RSP: 002b:00007ffcbb553e38 EFLAGS: 00000246 ORIG_RAX: 0000000000000106
RAX: ffffffffffffffda RBX: 0000560b875d5420 RCX: 00007f98bd711b0a
RDX: 00007ffcbb553e40 RSI: 0000560b875c3ef3 RDI: 00000000ffffff9c
RBP: 0000560ba76c3168 R08: 00063478c1c69200 R09: 7fffffffffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007ffcbb553e40 R14: 0000000000000000 R15: 00063478c1c69200
task:syz.1.428 state:R running task stack:25160 pid:7507 tgid:7500 ppid:5857 task_flags:0x400040 flags:0x20004006
Call Trace:
context_switch kernel/sched/core.c:5351 [inline]
__schedule+0x1737/0x4d30 kernel/sched/core.c:6954
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7281
irqentry_exit+0x6f/0x90 kernel/entry/common.c:196
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:__orc_find arch/x86/kernel/unwind_orc.c:102 [inline]
RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:227 [inline]
RIP: 0010:unwind_next_frame+0x1323/0x2390 arch/x86/kernel/unwind_orc.c:494
Code: 4c 89 f8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 0f b6 04 08 84 c0 75 27 49 63 07 4c 01 f8 49 8d 4f 04 4c 39 e0 48 0f 46 e9 <49> 8d 47 fc 48 0f 47 d8 4d 0f 46 ef 48 39 dd 76 a2 e9 7b ef ff ff
RSP: 0018:ffffc9001cb9ee18 EFLAGS: 00000287
RAX: ffffffff8242801f RBX: ffffffff8fbf16a8 RCX: ffffffff8fbf16a8
RDX: ffffffff8fbf16a4 RSI: ffffffff903fd566 RDI: ffffffff8be30a20
RBP: ffffffff8fbf16a8 R08: 000000000000000d R09: ffffffff8172cd05
R10: ffffc9001cb9ef38 R11: ffffffff81ac39b0 R12: ffffffff82428110
R13: ffffffff8fbf16a4 R14: ffffc9001cb9eee8 R15: ffffffff8fbf16a4
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
save_stack+0xf5/0x1f0 mm/page_owner.c:156
__reset_page_owner+0x71/0x1f0 mm/page_owner.c:308
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1248 [inline]
free_unref_folios+0xc66/0x14d0 mm/page_alloc.c:2763
folios_put_refs+0x559/0x640 mm/swap.c:992
folio_batch_release include/linux/pagevec.h:101 [inline]
mapping_try_invalidate+0x324/0x410 mm/truncate.c:554
drop_pagecache_sb+0x1a0/0x250 fs/drop_caches.c:40
__iterate_supers+0x13d/0x250 fs/super.c:924
drop_caches_sysctl_handler+0x97/0x170 fs/drop_caches.c:64
proc_sys_call_handler+0x4c6/0x700 fs/proc/proc_sysctl.c:600
iter_file_splice_write+0x93a/0x1000 fs/splice.c:738
do_splice_from fs/splice.c:935 [inline]
direct_splice_actor+0x101/0x160 fs/splice.c:1158
splice_direct_to_actor+0x5a5/0xcc0 fs/splice.c:1102
do_splice_direct_actor fs/splice.c:1201 [inline]
do_splice_direct+0x181/0x270 fs/splice.c:1227
do_sendfile+0x4da/0x7e0 fs/read_write.c:1370
__do_compat_sys_sendfile fs/read_write.c:1446 [inline]
__se_compat_sys_sendfile fs/read_write.c:1435 [inline]
__ia32_compat_sys_sendfile+0x120/0x1d0 fs/read_write.c:1435
do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
__do_fast_syscall_32+0xb6/0x2b0 arch/x86/entry/syscall_32.c:306
do_fast_syscall_32+0x34/0x80 arch/x86/entry/syscall_32.c:331
entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf7fb1539
RSP: 002b:00000000f509455c EFLAGS: 00000206 ORIG_RAX: 00000000000000bb
RAX: ffffffffffffffda RBX: 000000000000000a RCX: 0000000000000009
RDX: 0000000080002080 RSI: 000000000000023b RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
rcu: rcu_preempt kthread starved for 10477 jiffies! g21625 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:5351 [inline]
__schedule+0x1737/0x4d30 kernel/sched/core.c:6954
__schedule_loop kernel/sched/core.c:7036 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7051
schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285
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:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.16.0-syzkaller-06699-ge8d780dcd957 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82
Code: 53 e8 02 00 cc cc cc 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 5f 18 00 f3 0f 1e fa fb f4 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffffff8de07d80 EFLAGS: 000002c2
RAX: 24b82551ba91d400 RBX: ffffffff81969b38 RCX: 24b82551ba91d400
RDX: 0000000000000001 RSI: ffffffff8d979737 RDI: ffffffff8be30a80
RBP: ffffffff8de07eb8 R08: ffff8880b8632f5b R09: 1ffff110170c65eb
R10: dffffc0000000000 R11: ffffed10170c65ec R12: ffffffff8fa08df0
R13: 0000000000000000 R14: 0000000000000000 R15: 1ffffffff1bd2a18
FS: 0000000000000000(0000) GS:ffff888125c7e000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000f756ed1c CR3: 000000000df38000 CR4: 00000000003526f0
Call Trace:
arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:757
default_idle_call+0x74/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:190 [inline]
do_idle+0x1e8/0x510 kernel/sched/idle.c:330
cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:428
rest_init+0x2de/0x300 init/main.c:744
start_kernel+0x3a9/0x410 init/main.c:1097
x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:307
x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:288
common_startup_64+0x13e/0x147