rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P18718/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=89545, q=833 ncpus=2)
task:syz-executor state:R running task stack:28440 pid:18718 tgid:18718 ppid:8595 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5295 [inline]
__schedule+0xfee/0x6120 kernel/sched/core.c:6908
preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7235
irqentry_exit+0x17b/0x670 kernel/entry/common.c:239
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:rcu_read_lock_held_common kernel/rcu/update.c:109 [inline]
RIP: 0010:rcu_read_lock_held+0x1e/0x50 kernel/rcu/update.c:349
Code: 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa e8 87 16 a3 09 ba 01 00 00 00 85 c0 75 07 89 d0 c3 cc cc cc cc e8 d2 c8 00 00 <84> c0 74 1a e8 d9 09 01 00 84 c0 74 11 be ff ff ff ff 48 c7 c7 20
RSP: 0018:ffffc90004ccf938 EFLAGS: 00000286
RAX: 0000000000000001 RBX: 000000000008c534 RCX: 1ffff11027fe3446
RDX: 0000000000000000 RSI: ffffffff8c1afb20 RDI: ffffffff8e1268e0
RBP: ffff88801d180000 R08: 0000000000000006 R09: 0000000000001000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000001
R13: 0000000002ae02bb R14: 0000000000000002 R15: 0000000005140683
lookup_page_ext+0x6e/0x100 mm/page_ext.c:258
page_ext_iter_begin include/linux/page_ext.h:133 [inline]
__update_page_owner_free_handle.isra.0+0xa4/0x4d0 mm/page_owner.c:284
__reset_page_owner+0x93/0x190 mm/page_owner.c:321
reset_page_owner include/linux/page_owner.h:25 [inline]
__free_pages_prepare mm/page_alloc.c:1433 [inline]
__free_frozen_pages+0x7e1/0x10d0 mm/page_alloc.c:2978
qlink_free mm/kasan/quarantine.c:163 [inline]
qlist_free_all+0x47/0xe0 mm/kasan/quarantine.c:179
kasan_quarantine_reduce+0x1a0/0x1f0 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:4542 [inline]
slab_alloc_node mm/slub.c:4869 [inline]
__do_kmalloc_node mm/slub.c:5262 [inline]
__kvmalloc_node_noprof+0x316/0xa00 mm/slub.c:6755
simple_xattr_alloc+0x4a/0xa0 fs/xattr.c:1221
shmem_initxattrs+0x225/0x570 mm/shmem.c:4280
security_inode_init_security+0x242/0x370 security/security.c:1344
shmem_symlink+0x15f/0xa00 mm/shmem.c:4122
vfs_symlink fs/namei.c:5615 [inline]
vfs_symlink+0x178/0x4d0 fs/namei.c:5594
filename_symlinkat+0x2a6/0x560 fs/namei.c:5640
__do_sys_symlinkat fs/namei.c:5660 [inline]
__se_sys_symlinkat fs/namei.c:5655 [inline]
__x64_sys_symlinkat+0x9c/0xe0 fs/namei.c:5655
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f80fe99b857
RSP: 002b:00007fff5c59ea58 EFLAGS: 00000202 ORIG_RAX: 000000000000010a
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f80fe99b857
RDX: 00007f80fea33c52 RSI: 00000000ffffff9c RDI: 00007fff5c59eaf0
RBP: 00007fff5c59ea9c R08: 0000000000000001 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000232
R13: 00000000000927c0 R14: 00000000000eca01 R15: 00007fff5c59eaf0
rcu: rcu_preempt kthread starved for 1291 jiffies! g89545 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:27832 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5295 [inline]
__schedule+0xfee/0x6120 kernel/sched/core.c:6908
__schedule_loop kernel/sched/core.c:6990 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:7005
schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2095
rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2297
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x754/0xd80 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: 15291 Comm: kworker/u8:19 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/27/2026
Workqueue: events_unbound nsim_dev_trap_report_work
RIP: 0010:__sanitizer_cov_trace_const_cmp1+0x0/0x20 kernel/kcov.c:299
Code: 0c 24 48 89 f2 48 89 fe bf 06 00 00 00 e9 b8 fe ff ff 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 48 8b 0c 24 40 0f b6 d6 40 0f b6 f7 bf 01 00 00 00 e9
RSP: 0018:ffffc90000a08798 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff8a5058ea
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffff88805a61e040 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff88805a61e0c4
R13: 0000000000000000 R14: 0000000000000000 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff888124445000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555570ea2a28 CR3: 0000000034b90000 CR4: 00000000003526f0
Call Trace:
ip6_packet_match net/ipv6/netfilter/ip6_tables.c:60 [inline]
ip6t_do_table+0x613/0x1c90 net/ipv6/netfilter/ip6_tables.c:306
ip6table_mangle_hook+0xc3/0x770 net/ipv6/netfilter/ip6table_mangle.c:73
nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
nf_hook_slow+0xbf/0x220 net/netfilter/core.c:623
nf_hook.constprop.0+0x2a6/0x750 include/linux/netfilter.h:273
NF_HOOK include/linux/netfilter.h:316 [inline]
ipv6_rcv+0xa4/0x3d0 net/ipv6/ip6_input.c:311
__netif_receive_skb_one_core+0x12d/0x1e0 net/core/dev.c:6164
__netif_receive_skb+0x1f/0x120 net/core/dev.c:6277
process_backlog+0x37a/0x1580 net/core/dev.c:6628
__napi_poll.constprop.0+0xaf/0x450 net/core/dev.c:7692
napi_poll net/core/dev.c:7755 [inline]
net_rx_action+0xa40/0xf20 net/core/dev.c:7912
handle_softirqs+0x1eb/0x9e0 kernel/softirq.c:622
do_softirq kernel/softirq.c:523 [inline]
do_softirq+0xac/0xe0 kernel/softirq.c:510
__local_bh_enable_ip+0xf8/0x120 kernel/softirq.c:450
local_bh_enable include/linux/bottom_half.h:33 [inline]
__alloc_skb+0x5db/0x710 net/core/skbuff.c:697
alloc_skb include/linux/skbuff.h:1383 [inline]
nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:819 [inline]
nsim_dev_trap_report drivers/net/netdevsim/dev.c:876 [inline]
nsim_dev_trap_report_work+0x2af/0xd10 drivers/net/netdevsim/dev.c:922
process_one_work+0x9d7/0x1920 kernel/workqueue.c:3275
process_scheduled_works kernel/workqueue.c:3358 [inline]
worker_thread+0x5da/0xe40 kernel/workqueue.c:3439
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245