syzbot

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P20569/1:b..l
rcu: 	(detected by 0, t=10503 jiffies, g=103433, q=2372 ncpus=2)
task:syz.7.3700      state:R  running task     stack:26808 pid:20569 tgid:20562 ppid:11444  task_flags:0x400140 flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5397 [inline]
 __schedule+0x16a2/0x4cb0 kernel/sched/core.c:6786
 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7109
 irqentry_exit+0x6f/0x90 kernel/entry/common.c:307
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:19 [inline]
RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:109 [inline]
RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:127 [inline]
RIP: 0010:lock_release+0x9c/0x3e0 kernel/locking/lockdep.c:5888
Code: 0f 85 35 02 00 00 65 4c 8b 3c 25 08 10 9d 92 41 83 bf ec 0a 00 00 00 0f 85 1e 02 00 00 49 81 3e 00 c3 60 93 0f 84 11 02 00 00 <48> c7 44 24 20 00 00 00 00 9c 8f 44 24 20 48 8b 5c 24 20 fa 48 c7
RSP: 0018:ffffc9000466f330 EFLAGS: 00000202
RAX: 0000000000000000 RBX: ffffc9000466f401 RCX: 6f59f5a484fa8600
RDX: ffffffff903d4801 RSI: ffffffff8be1c9e0 RDI: ffffffff8be1c9a0
RBP: dffffc0000000000 R08: ffffc9000466f4c7 R09: 0000000000000000
R10: ffffc9000466f4b8 R11: fffff520008cde99 R12: ffffc9000466f918
R13: ffffffff8172aae5 R14: ffffffff8e13f0e0 R15: ffff88807ea61e00
 rcu_lock_release include/linux/rcupdate.h:341 [inline]
 rcu_read_unlock include/linux/rcupdate.h:871 [inline]
 class_rcu_destructor include/linux/rcupdate.h:1155 [inline]
 unwind_next_frame+0x19a9/0x2390 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+0xf7/0x1f0 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+0xc65/0xe60 mm/page_alloc.c:2706
 discard_slab mm/slub.c:2717 [inline]
 __put_partials+0x161/0x1c0 mm/slub.c:3186
 put_cpu_partial+0x17c/0x250 mm/slub.c:3261
 __slab_free+0x2f7/0x400 mm/slub.c:4513
 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:4148 [inline]
 slab_alloc_node mm/slub.c:4197 [inline]
 __do_kmalloc_node mm/slub.c:4327 [inline]
 __kvmalloc_node_noprof+0x2b0/0x5f0 mm/slub.c:5015
 bucket_table_alloc lib/rhashtable.c:186 [inline]
 rhashtable_init_noprof+0x4ee/0xbb0 lib/rhashtable.c:1075
 nbp_vlan_init+0x1e1/0x440 net/bridge/br_vlan.c:1269
 br_add_if+0xaa1/0xec0 net/bridge/br_if.c:676
 add_del_if net/bridge/br_ioctl.c:99 [inline]
 br_ioctl_stub+0x6aa/0xc80 net/bridge/br_ioctl.c:462
 br_ioctl_call net/socket.c:1163 [inline]
 sock_ioctl+0x4d5/0x790 net/socket.c:1265
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:907 [inline]
 __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:893
 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: 0033:0x7fd33cf8e929
RSP: 002b:00007fd33a5b0038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fd33d1b6320 RCX: 00007fd33cf8e929
RDX: 0000200000000000 RSI: 00000000000089a2 RDI: 0000000000000009
RBP: 00007fd33d010b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fd33d1b6320 R15: 00007ffc3bf6e6b8
 </TASK>
rcu: rcu_preempt kthread starved for 547 jiffies! g103433 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:27128 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5397 [inline]
 __schedule+0x16a2/0x4cb0 kernel/sched/core.c:6786
 __schedule_loop kernel/sched/core.c:6864 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6879
 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2054
 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2256
 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
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 20568 Comm: syz.7.3700 Not tainted 6.16.0-rc6-syzkaller-00002-g155a3c003e55 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:ip_rcv_finish_core+0xe11/0x1c00 net/ipv4/ip_input.c:374
Code: b6 04 28 84 c0 0f 85 e7 0b 00 00 41 8b 1c 24 31 ff 89 de e8 21 e1 e7 f7 85 db 0f 84 7e 01 00 00 e8 d4 dc e7 f7 4c 8b 64 24 10 <4c> 8d 75 3c 4c 89 f0 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 b3 0a
RSP: 0018:ffffc90000a08820 EFLAGS: 00000246
RAX: ffffffff89d8557c RBX: 0000000000000001 RCX: ffff88807ea63c00
RDX: 0000000000000100 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffff888080c88500 R08: ffff88807ea63c00 R09: 0000000000000004
R10: 0000000000000003 R11: ffffffff89d834b0 R12: 1ffff110101910ab
R13: dffffc0000000000 R14: ffff88814c92f844 R15: ffff888080c88558
FS:  00007fd33a9d36c0(0000) GS:ffff888125d4f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f9624582ef8 CR3: 00000000564ac000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 ip_rcv_finish+0x14c/0x2f0 net/ipv4/ip_input.c:446
 NF_HOOK+0x30c/0x3a0 include/linux/netfilter.h:317
 __netif_receive_skb_one_core net/core/dev.c:5977 [inline]
 __netif_receive_skb+0x143/0x380 net/core/dev.c:6090
 process_backlog+0x60e/0x14f0 net/core/dev.c:6442
 __napi_poll+0xc4/0x480 net/core/dev.c:7414
 napi_poll net/core/dev.c:7478 [inline]
 net_rx_action+0x707/0xe30 net/core/dev.c:7605
 handle_softirqs+0x283/0x870 kernel/softirq.c:579
 __do_softirq kernel/softirq.c:613 [inline]
 invoke_softirq kernel/softirq.c:453 [inline]
 __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1050
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:should_fail_usercopy+0x4/0x20 lib/fault-inject-usercopy.c:36
Code: f7 e8 70 3f 33 fd eb a9 cc cc cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa <e8> 87 e9 d1 fc be 01 00 00 00 48 c7 c7 20 af 8c 8e e9 f6 ed ff ff
RSP: 0018:ffffc9000465fa18 EFLAGS: 00000286
RAX: 6bed3a1466885100 RBX: 0000000000000038 RCX: 6bed3a1466885100
RDX: 0000000000000000 RSI: ffffffff8db72142 RDI: ffffffff8be1ca00
RBP: ffffc9000465fc30 R08: 0000000000000000 R09: ffffffff820a2010
R10: ffffc9000465faa0 R11: fffff520008cbf5b R12: 0000000000000002
R13: dffffc0000000000 R14: ffffc9000465faa0 R15: 0000200000352600
 _inline_copy_from_user include/linux/uaccess.h:163 [inline]
 _copy_from_user+0x2d/0xb0 lib/usercopy.c:18
 copy_from_user include/linux/uaccess.h:212 [inline]
 copy_msghdr_from_user net/socket.c:2496 [inline]
 recvmsg_copy_msghdr net/socket.c:2752 [inline]
 ___sys_recvmsg+0x12e/0x510 net/socket.c:2824
 do_recvmmsg+0x307/0x770 net/socket.c:2923
 __sys_recvmmsg net/socket.c:2997 [inline]
 __do_sys_recvmmsg net/socket.c:3020 [inline]
 __se_sys_recvmmsg net/socket.c:3013 [inline]
 __x64_sys_recvmmsg+0x190/0x240 net/socket.c:3013
 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: 0033:0x7fd33cf8e929
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fd33a9d3038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007fd33d1b6240 RCX: 00007fd33cf8e929
RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000005
RBP: 00007fd33d010b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000001 R14: 00007fd33d1b6240 R15: 00007ffc3bf6e6b8
 </TASK>