rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6041/1:b..l P7880/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=23253, q=1158 ncpus=2)
task:syz.6.433 state:R running task stack:25336 pid:7880 tgid:7879 ppid:6346 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x149b/0x4fd0 kernel/sched/core.c:6863
preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7190
irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:kasan_check_range+0x1dd/0x2c0 mm/kasan/generic.c:200
Code: e4 49 0f 49 dc 48 83 e3 f8 49 29 dc 74 12 41 80 3b 00 0f 85 b8 00 00 00 49 ff c3 49 ff cc 75 ee 5b 41 5c 41 5d 41 5e 41 5f 5d 99 41 e9 fe cc 45 84 ff 75 63 41 f7 c7 00 ff 00 00 75 5f 41 f7
RSP: 0018:ffffc9000b057590 EFLAGS: 00000256
RAX: ffffc9000b057b01 RBX: 0000000000000010 RCX: ffffffff81740b6e
RDX: 0000000000000001 RSI: 0000000000000010 RDI: ffffc9000b0576d8
RBP: 0000000000000000 R08: ffffc9000b0576e7 R09: 1ffff9200160aedc
R10: dffffc0000000000 R11: fffff5200160aedd R12: ffffc9000b0576d8
R13: 1ffff9200160aed3 R14: ffffc9000b0576d8 R15: ffffc9000b0576d0
__asan_memset+0x22/0x50 mm/kasan/shadow.c:84
unwind_next_frame+0xeae/0x23d0 arch/x86/kernel/unwind_orc.c:607
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:165
__reset_page_owner+0x71/0x1f0 mm/page_owner.c:320
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1395 [inline]
__free_frozen_pages+0xbc8/0xd30 mm/page_alloc.c:2943
vfree+0x25a/0x400 mm/vmalloc.c:3466
__do_replace+0x248/0xaa0 net/ipv4/netfilter/arp_tables.c:946
do_replace net/ipv4/netfilter/arp_tables.c:989 [inline]
do_arpt_set_ctl+0xa2a/0xf10 net/ipv4/netfilter/arp_tables.c:1429
nf_setsockopt+0x26f/0x290 net/netfilter/nf_sockopt.c:101
do_sock_setsockopt+0x17c/0x1b0 net/socket.c:2322
__sys_setsockopt net/socket.c:2347 [inline]
__do_sys_setsockopt net/socket.c:2353 [inline]
__se_sys_setsockopt net/socket.c:2350 [inline]
__x64_sys_setsockopt+0x13f/0x1b0 net/socket.c:2350
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fda9d38f749
RSP: 002b:00007fda9e2b4038 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007fda9d5e5fa0 RCX: 00007fda9d38f749
RDX: 0000000000000060 RSI: 0a02000000000000 RDI: 0000000000000003
RBP: 00007fda9d413f91 R08: 0000000000000438 R09: 0000000000000000
R10: 0000200000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fda9d5e6038 R14: 00007fda9d5e5fa0 R15: 00007ffe8670ed88
task:udevd state:R running task stack:23864 pid:6041 tgid:6041 ppid:5193 task_flags:0x400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x149b/0x4fd0 kernel/sched/core.c:6863
preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7190
irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216
asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:debug_lockdep_rcu_enabled+0x0/0x40 kernel/rcu/update.c:319
Code: 48 8d 3d 83 d7 2b 04 48 c7 c6 10 f7 77 8d 67 48 0f b9 3a 90 eb ca cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 31 c0 83 3d 07 8d 28 04 00 74 1e 83 3d 1a bc 28 04 00
RSP: 0018:ffffc90004f271d0 EFLAGS: 00000202
RAX: ffffc90004f28000 RBX: ffffffff909b2601 RCX: ffffc90004f27ca8
RDX: ffffc90004f27201 RSI: dffffc0000000000 RDI: ffffc90004f272b0
RBP: dffffc0000000000 R08: ffffc90004f27c90 R09: ffffc90004f272f8
R10: dffffc0000000000 R11: fffff520009e4e61 R12: ffffc90004f27ca0
R13: ffffc90004f20000 R14: ffffc90004f272a8 R15: ffffffff8173fd65
rcu_read_unlock include/linux/rcupdate.h:895 [inline]
class_rcu_destructor include/linux/rcupdate.h:1195 [inline]
unwind_next_frame+0x1a64/0x23d0 arch/x86/kernel/unwind_orc.c:695
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:56 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
unpoison_slab_object mm/kasan/common.c:339 [inline]
__kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:365
kasan_slab_alloc include/linux/kasan.h:252 [inline]
slab_post_alloc_hook mm/slub.c:4953 [inline]
slab_alloc_node mm/slub.c:5263 [inline]
kmem_cache_alloc_node_noprof+0x43c/0x720 mm/slub.c:5315
__alloc_skb+0x1dc/0x3a0 net/core/skbuff.c:679
alloc_skb include/linux/skbuff.h:1383 [inline]
alloc_skb_with_frags+0xca/0x890 net/core/skbuff.c:6712
sock_alloc_send_pskb+0x84d/0x980 net/core/sock.c:2995
unix_dgram_sendmsg+0x454/0x1840 net/unix/af_unix.c:2130
sock_sendmsg_nosec net/socket.c:727 [inline]
__sock_sendmsg+0x21c/0x270 net/socket.c:742
sock_write_iter+0x279/0x360 net/socket.c:1195
new_sync_write fs/read_write.c:593 [inline]
vfs_write+0x5c9/0xb30 fs/read_write.c:686
ksys_write+0x145/0x250 fs/read_write.c:738
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff4e4aa7407
RSP: 002b:00007fffa15c8f90 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007ff4e517c880 RCX: 00007ff4e4aa7407
RDX: 0000000000000000 RSI: 00007fffa15c9037 RDI: 000000000000000a
RBP: 000000000000000a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00007ff4e517c6e8
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
rcu: rcu_preempt kthread starved for 10596 jiffies! g23253 f0x0 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:27840 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x149b/0x4fd0 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6960
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+0x510/0xa50 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: 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: 3e b4 b6 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 73 c1 0e 00 f3 0f 1e fa fb f4 13 b4 b6 f5 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90000197e20 EFLAGS: 000002c2
RAX: 0000000000521797 RBX: ffffffff819713ee RCX: 0000000080000001
RDX: 0000000000000001 RSI: ffffffff8d79201e RDI: ffffffff8bc083e0
RBP: ffffc90000197f10 R08: ffff8880b87336db R09: 1ffff110170e66db
R10: dffffc0000000000 R11: ffffed10170e66dc R12: ffffffff8f822270
R13: 1ffff1100385fb70 R14: 0000000000000001 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff888125f1f000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8630b72100 CR3: 0000000076042000 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:191 [inline]
do_idle+0x1be/0x4d0 kernel/sched/idle.c:332
cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:430
start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:312
common_startup_64+0x13e/0x147