rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5821/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=21989, q=911135 ncpus=2)
task:syz-executor state:R running task stack:21080 pid:5821 tgid:5821 ppid:5817 task_flags:0x400140 flags:0x00080001
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6929
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7256
irqentry_exit+0x6f/0x90 kernel/entry/common.c:211
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:rcu_preempt_read_exit kernel/rcu/tree_plugin.h:396 [inline]
RIP: 0010:__rcu_read_unlock+0x35/0xe0 kernel/rcu/tree_plugin.h:435
Code: 54 53 49 bf 00 00 00 00 00 fc ff df 65 48 8b 3c 25 08 50 6e 92 48 8d 9f 84 04 00 00 49 89 dc 49 c1 ec 03 43 0f b6 04 3c 84 c0 <75> 4f ff 0b 75 1d 4c 8d b7 88 04 00 00 4c 89 f0 48 c1 e8 03 42 0f
RSP: 0018:ffffc90003037168 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffff888026d3c104 RCX: 0729c2b51fc54300
RDX: 0000000000000004 RSI: ffffffff8d8f4ef6 RDI: ffff888026d3bc80
RBP: dffffc0000000000 R08: ffffc900030374e0 R09: ffffc900030372b8
R10: dffffc0000000000 R11: fffff52000606e59 R12: 1ffff11004da7820
R13: ffffc90003030000 R14: ffffc90003037268 R15: dffffc0000000000
rcu_read_unlock include/linux/rcupdate.h:899 [inline]
class_rcu_destructor include/linux/rcupdate.h:1195 [inline]
unwind_next_frame+0x19ae/0x2390 arch/x86/kernel/unwind_orc.c:680
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:311
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1394 [inline]
__free_frozen_pages+0xbc4/0xd30 mm/page_alloc.c:2906
discard_slab mm/slub.c:3330 [inline]
__put_partials+0x146/0x170 mm/slub.c:3876
put_cpu_partial+0x1f2/0x2e0 mm/slub.c:3951
__slab_free+0x2b9/0x390 mm/slub.c:5929
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:352
kasan_slab_alloc include/linux/kasan.h:252 [inline]
slab_post_alloc_hook mm/slub.c:4978 [inline]
slab_alloc_node mm/slub.c:5288 [inline]
kmem_cache_alloc_noprof+0x367/0x6e0 mm/slub.c:5295
anon_vma_chain_alloc mm/rmap.c:141 [inline]
anon_vma_fork+0x1f1/0x500 mm/rmap.c:363
dup_mmap+0x9e2/0x1b10 mm/mmap.c:1797
dup_mm kernel/fork.c:1489 [inline]
copy_mm+0x13c/0x4b0 kernel/fork.c:1541
copy_process+0x1706/0x3c00 kernel/fork.c:2181
kernel_clone+0x21e/0x840 kernel/fork.c:2609
__do_sys_clone kernel/fork.c:2750 [inline]
__se_sys_clone kernel/fork.c:2734 [inline]
__x64_sys_clone+0x18b/0x1e0 kernel/fork.c:2734
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f81b0985e13
RSP: 002b:00007ffe90c95878 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f81b0985e13
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001
R10: 00005555758f57d0 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000008 R14: 000000000004588a R15: 00007ffe90c95a10
rcu: rcu_preempt kthread starved for 6543 jiffies! g21989 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R running task stack:27240 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6929
__schedule_loop kernel/sched/core.c:7011 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7026
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:463
ret_from_fork+0x4bc/0x870 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: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82
Code: 5e d3 c9 f5 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 93 c1 21 00 f3 0f 1e fa fb f4 33 d3 c9 f5 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90000197de0 EFLAGS: 000002c6
RAX: 37ae2c8dfdd95d00 RBX: ffffffff81967b47 RCX: 37ae2c8dfdd95d00
RDX: 0000000000000001 RSI: ffffffff8d70e27f RDI: ffffffff8bbf0760
RBP: ffffc90000197f10 R08: ffff8880b8932fdb R09: 1ffff110171265fb
R10: dffffc0000000000 R11: ffffed10171265fc R12: ffffffff8f7ceb70
R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff110038d9b58
FS: 0000000000000000(0000) GS:ffff88812623b000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffe61c9af9c CR3: 000000005f4e2000 CR4: 0000000000350ef0
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+0x73/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:190 [inline]
do_idle+0x1e7/0x510 kernel/sched/idle.c:330
cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:428
start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:315
common_startup_64+0x13e/0x147