syzbot

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P3544/1:b..l
	(detected by 0, t=10502 jiffies, g=19745, q=1001)
task:udevd           state:R  running task     stack:22176 pid: 3544 ppid:     1 flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5027 [inline]
 __schedule+0x12c4/0x45b0 kernel/sched/core.c:6373
 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6777
 irqentry_exit+0x53/0x80 kernel/entry/common.c:432
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x60 kernel/kcov.c:202
Code: 1f 84 00 00 00 00 00 0f 1f 00 53 48 89 fb e8 17 00 00 00 48 8b 3d c8 dd 89 0c 48 89 de 5b e9 07 05 49 00 cc cc cc cc cc cc cc <48> 8b 04 24 65 48 8b 0d d4 ea 81 7e 65 8b 15 d5 ea 81 7e 81 e2 00
RSP: 0018:ffffc90002eaf600 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 1ffff1100ef53dd6 RCX: ffff88807d983b80
RDX: ffff88807d983b80 RSI: 0000000000000000 RDI: ffff888077a9ef40
RBP: 0000000000000000 R08: ffffffff81dbbcb0 R09: fffffbfff2131221
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: ffff888077a9eeb0 R14: ffff888077a9ef40 R15: 1ffff920005d5ee0
 lockref_put_return+0x5/0x10 lib/lockref.c:146
 fast_dput+0x58/0x290 fs/dcache.c:760
 dput+0xb7/0x1a0 fs/dcache.c:880
 step_into+0x352/0xe90 fs/namei.c:1815
 walk_component+0x359/0x610 fs/namei.c:1982
 link_path_walk+0x642/0xd90
 path_lookupat+0xa9/0x450 fs/namei.c:2454
 filename_lookup+0x230/0x5c0 fs/namei.c:2484
 user_path_at_empty+0x40/0x180 fs/namei.c:2883
 user_path_at include/linux/namei.h:57 [inline]
 vfs_statx+0x106/0x3b0 fs/stat.c:221
 vfs_fstatat fs/stat.c:243 [inline]
 __do_sys_newfstatat fs/stat.c:411 [inline]
 __se_sys_newfstatat fs/stat.c:405 [inline]
 __x64_sys_newfstatat+0x12c/0x1b0 fs/stat.c:405
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f0e5affd5f4
RSP: 002b:00007ffe7be08038 EFLAGS: 00000246 ORIG_RAX: 0000000000000106
RAX: ffffffffffffffda RBX: 000055b92a87b710 RCX: 00007f0e5affd5f4
RDX: 00007ffe7be08048 RSI: 00007ffe7be084d8 RDI: 00000000ffffff9c
RBP: 00007ffe7be080d8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffe7be084d8
R13: 00007ffe7be08048 R14: 000055b92a87b910 R15: 0000000000000000
 </TASK>
rcu: rcu_preempt kthread starved for 10536 jiffies! g19745 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:27064 pid:   15 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5027 [inline]
 __schedule+0x12c4/0x45b0 kernel/sched/core.c:6373
 schedule+0x11b/0x1f0 kernel/sched/core.c:6456
 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1914
 rcu_gp_fqs_loop+0x2bf/0x1080 kernel/rcu/tree.c:1972
 rcu_gp_kthread+0xa4/0x360 kernel/rcu/tree.c:2145
 kthread+0x3f6/0x4f0 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
NMI backtrace for cpu 0
CPU: 0 PID: 6556 Comm: syz.0.555 Not tainted 5.15.175-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/25/2024
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline]
 rcu_check_gp_kthread_starvation+0x1d2/0x240 kernel/rcu/tree_stall.h:487
 print_other_cpu_stall+0x137a/0x14d0 kernel/rcu/tree_stall.h:592
 check_cpu_stall kernel/rcu/tree_stall.h:745 [inline]
 rcu_pending kernel/rcu/tree.c:3932 [inline]
 rcu_sched_clock_irq+0xa38/0x1150 kernel/rcu/tree.c:2619
 update_process_times+0x196/0x200 kernel/time/timer.c:1818
 tick_sched_handle kernel/time/tick-sched.c:254 [inline]
 tick_sched_timer+0x386/0x550 kernel/time/tick-sched.c:1473
 __run_hrtimer kernel/time/hrtimer.c:1688 [inline]
 __hrtimer_run_queues+0x55b/0xcf0 kernel/time/hrtimer.c:1752
 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1814
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline]
 __sysvec_apic_timer_interrupt+0x13b/0x4b0 arch/x86/kernel/apic/apic.c:1114
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0x4d/0xc0 arch/x86/kernel/apic/apic.c:1108
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:unwind_next_frame+0xbc3/0x1fa0 arch/x86/kernel/unwind_orc.c:547
Code: 24 60 0f b6 04 08 84 c0 48 8b 5c 24 68 48 8b 6c 24 18 0f 85 39 10 00 00 c6 03 00 ba 10 00 00 00 48 8b 5c 24 20 48 89 df 31 f6 <e8> f8 ad 91 00 48 ba 00 00 00 00 00 fc ff df 4c 8b 04 24 e9 72 05
RSP: 0018:ffffc90000005c28 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffffc90000005d30 RCX: dffffc0000000000
RDX: 0000000000000010 RSI: 0000000000000000 RDI: ffffc90000005d30
RBP: ffffffff8e83dee4 R08: 0000000000000003 R09: ffffc90000005dd0
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffffffff1d07bdc
R13: 1ffffffff1d07bdc R14: ffffffff8e83dee0 R15: ffffc90000005ce0
 arch_stack_walk+0x10d/0x140 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x113/0x1c0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:434 [inline]
 __kasan_slab_alloc+0x8e/0xc0 mm/kasan/common.c:467
 kasan_slab_alloc include/linux/kasan.h:254 [inline]
 slab_post_alloc_hook+0x53/0x380 mm/slab.h:519
 slab_alloc_node mm/slub.c:3220 [inline]
 kmem_cache_alloc_node+0x121/0x2c0 mm/slub.c:3256
 __alloc_skb+0xdd/0x590 net/core/skbuff.c:415
 alloc_skb include/linux/skbuff.h:1162 [inline]
 alloc_skb_with_frags+0xa3/0x780 net/core/skbuff.c:6170
 sock_alloc_send_pskb+0x915/0xa50 net/core/sock.c:2530
 __ip6_append_data+0x28f2/0x3f10 net/ipv6/ip6_output.c:1663
 ip6_append_data+0x1d6/0x300 net/ipv6/ip6_output.c:1837
 icmp6_send+0x165f/0x21e0 net/ipv6/icmp.c:622
 __icmpv6_send include/linux/icmpv6.h:28 [inline]
 icmpv6_send include/linux/icmpv6.h:49 [inline]
 ip6_link_failure+0x37/0x4a0 net/ipv6/route.c:2788
 dst_link_failure include/net/dst.h:422 [inline]
 ip6_tnl_xmit+0x10d5/0x2500 net/ipv6/ip6_tunnel.c:1275
 ipxip6_tnl_xmit net/ipv6/ip6_tunnel.c:1391 [inline]
 ip6_tnl_start_xmit+0xbe0/0x1470 net/ipv6/ip6_tunnel.c:1440
 __netdev_start_xmit include/linux/netdevice.h:5019 [inline]
 netdev_start_xmit include/linux/netdevice.h:5033 [inline]
 xmit_one net/core/dev.c:3617 [inline]
 dev_hard_start_xmit+0x298/0x7a0 net/core/dev.c:3633
 __dev_queue_xmit+0x1c8e/0x32b0 net/core/dev.c:4256
 neigh_output include/net/neighbour.h:509 [inline]
 ip6_finish_output2+0xee8/0x15a0 net/ipv6/ip6_output.c:130
 ip6tunnel_xmit include/net/ip6_tunnel.h:160 [inline]
 udp_tunnel6_xmit_skb+0x538/0x970 net/ipv6/ip6_udp_tunnel.c:109
 geneve6_xmit_skb drivers/net/geneve.c:1087 [inline]
 geneve_xmit+0x25ff/0x3480 drivers/net/geneve.c:1116
 __netdev_start_xmit include/linux/netdevice.h:5019 [inline]
 netdev_start_xmit include/linux/netdevice.h:5033 [inline]
 xmit_one net/core/dev.c:3617 [inline]
 dev_hard_start_xmit+0x298/0x7a0 net/core/dev.c:3633
 __dev_queue_xmit+0x1c8e/0x32b0 net/core/dev.c:4256
 neigh_output include/net/neighbour.h:509 [inline]
 ip6_finish_output2+0xee8/0x15a0 net/ipv6/ip6_output.c:130
 dst_output include/net/dst.h:443 [inline]
 NF_HOOK include/linux/netfilter.h:302 [inline]
 ndisc_send_skb+0xae0/0x13c0 net/ipv6/ndisc.c:511
 addrconf_rs_timer+0x357/0x610 net/ipv6/addrconf.c:3959
 call_timer_fn+0x16d/0x560 kernel/time/timer.c:1451
 expire_timers kernel/time/timer.c:1496 [inline]
 __run_timers+0x67c/0x890 kernel/time/timer.c:1767
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1780
 handle_softirqs+0x3a7/0x930 kernel/softirq.c:558
 __do_softirq kernel/softirq.c:592 [inline]
 invoke_softirq kernel/softirq.c:432 [inline]
 __irq_exit_rcu+0x157/0x240 kernel/softirq.c:641
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:653
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:__sanitizer_cov_trace_pc+0x41/0x60 kernel/kcov.c:211
Code: ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 34 16 00 00 00 74 2c 8b 91 10 16 00 00 83 fa 02 75 21 48 8b 91 18 16 00 00 48 8b 32 <48> 8d 7e 01 8b 89 14 16 00 00 48 39 cf 73 08 48 89 44 f2 08 48 89
RSP: 0018:ffffc900032ae9f8 EFLAGS: 00000246
RAX: ffffffff8188b359 RBX: ffffc900032aeae0 RCX: ffff88802a771dc0
RDX: ffffc90004ac9000 RSI: 0000000000006e6e RDI: 000000000000002c
RBP: ffffc900032aeb60 R08: 0000000000000002 R09: 0000000000000000
R10: 0000000000000000 R11: dffffc0000000001 R12: 000000000000002c
R13: ffffffff8c9eeb20 R14: ffffc900032aeac0 R15: dffffc0000000000
 perf_trace_buf_alloc+0x19/0x2e0 kernel/trace/trace_event_perf.c:403
 perf_trace_lock_acquire+0x1eb/0x4a0 include/trace/events/lock.h:13
 trace_lock_acquire include/trace/events/lock.h:13 [inline]
 lock_acquire+0x4c6/0x4f0 kernel/locking/lockdep.c:5594
 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:312
 rcu_read_lock include/linux/rcupdate.h:739 [inline]
 BPF_PROG_RUN_ARRAY include/linux/bpf.h:1333 [inline]
 trace_call_bpf+0x146/0x660 kernel/trace/bpf_trace.c:127
 perf_trace_run_bpf_submit+0x7b/0x1d0 kernel/events/core.c:9991
 perf_trace_lock_acquire+0x3bf/0x4a0 include/trace/events/lock.h:13
 trace_lock_acquire include/trace/events/lock.h:13 [inline]
 lock_acquire+0x4c6/0x4f0 kernel/locking/lockdep.c:5594
 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:312
 rcu_read_lock include/linux/rcupdate.h:739 [inline]
 is_bpf_text_address+0x1d/0x260 kernel/bpf/core.c:721
 kernel_text_address kernel/extable.c:151 [inline]
 __kernel_text_address+0x94/0x100 kernel/extable.c:105
 unwind_get_return_address+0x49/0x80 arch/x86/kernel/unwind_orc.c:323
 arch_stack_walk+0xf3/0x140 arch/x86/kernel/stacktrace.c:26
 stack_trace_save+0x113/0x1c0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:434 [inline]
 ____kasan_kmalloc+0xba/0xf0 mm/kasan/common.c:513
 kasan_kmalloc include/linux/kasan.h:264 [inline]
 kmem_cache_alloc_trace+0x143/0x290 mm/slub.c:3247
 kmalloc include/linux/slab.h:591 [inline]
 kzalloc include/linux/slab.h:721 [inline]
 sctp_add_bind_addr+0x85/0x3a0 net/sctp/bind_addr.c:150
 sctp_copy_local_addr_list+0x2e7/0x4c0 net/sctp/protocol.c:166
 sctp_bind_addr_copy+0xa9/0x3b0 net/sctp/bind_addr.c:56
 sctp_connect_new_asoc+0x2e5/0x6a0 net/sctp/socket.c:1092
 sctp_sendmsg_new_asoc net/sctp/socket.c:1690 [inline]
 sctp_sendmsg+0x1cd9/0x3370 net/sctp/socket.c:2004
 sock_sendmsg_nosec net/socket.c:704 [inline]
 __sock_sendmsg net/socket.c:716 [inline]
 ____sys_sendmsg+0x59e/0x8f0 net/socket.c:2436
 ___sys_sendmsg+0x252/0x2e0 net/socket.c:2490
 __sys_sendmsg net/socket.c:2519 [inline]
 __do_sys_sendmsg net/socket.c:2528 [inline]
 __se_sys_sendmsg+0x19a/0x260 net/socket.c:2526
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f6c5084cd29
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:00007f6c4e6bd038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f6c50a3cfa0 RCX: 00007f6c5084cd29
RDX: 0000000000000000 RSI: 00000000200003c0 RDI: 0000000000000003
RBP: 00007f6c508c8aa8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f6c50a3cfa0 R15: 00007ffee10c1268
 </TASK>