[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 86.671407][ T27] audit: type=1800 audit(1579916612.732:25): pid=9549 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 86.694301][ T27] audit: type=1800 audit(1579916612.732:26): pid=9549 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 86.753475][ T27] audit: type=1800 audit(1579916612.732:27): pid=9549 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="restorecond" dev="sda1" ino=2436 res=0 [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.0.157' (ECDSA) to the list of known hosts. executing program executing program executing program executing program executing program executing program syzkaller login: [ 418.673893][ C1] rcu: INFO: rcu_preempt self-detected stall on CPU [ 418.680837][ C1] rcu: 1-....: (1 GPs behind) idle=86e/1/0x4000000000000002 softirq=16299/16301 fqs=5207 [ 418.690939][ C1] (t=10500 jiffies g=9489 q=80) [ 418.695948][ C1] NMI backtrace for cpu 1 [ 418.700274][ C1] CPU: 1 PID: 9708 Comm: syz-executor976 Not tainted 5.5.0-rc7-syzkaller #0 [ 418.708985][ C1] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 418.719180][ C1] Call Trace: [ 418.722468][ C1] [ 418.725552][ C1] dump_stack+0x197/0x210 [ 418.729883][ C1] nmi_cpu_backtrace.cold+0x70/0xb2 [ 418.735162][ C1] ? lapic_can_unplug_cpu.cold+0x3a/0x3a [ 418.740843][ C1] nmi_trigger_cpumask_backtrace+0x23b/0x28b [ 418.746900][ C1] arch_trigger_cpumask_backtrace+0x14/0x20 [ 418.752882][ C1] rcu_dump_cpu_stacks+0x183/0x1cf [ 418.758058][ C1] ? find_next_bit+0x107/0x130 [ 418.762842][ C1] rcu_sched_clock_irq.cold+0x509/0xc0d [ 418.768413][ C1] ? raise_softirq+0x138/0x340 [ 418.773239][ C1] update_process_times+0x2d/0x70 [ 418.778288][ C1] tick_sched_handle+0xa2/0x190 [ 418.783139][ C1] tick_sched_timer+0x53/0x140 [ 418.787979][ C1] __hrtimer_run_queues+0x364/0xe40 [ 418.793191][ C1] ? tick_sched_do_timer+0x1b0/0x1b0 [ 418.798455][ C1] ? hrtimer_init+0x330/0x330 [ 418.803178][ C1] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 418.808952][ C1] ? ktime_get_update_offsets_now+0x2ce/0x430 [ 418.815024][ C1] hrtimer_interrupt+0x314/0x770 [ 418.820110][ C1] smp_apic_timer_interrupt+0x160/0x610 [ 418.825739][ C1] apic_timer_interrupt+0xf/0x20 [ 418.830651][ C1] [ 418.833642][ C1] RIP: 0010:debug_lockdep_rcu_enabled.part.0+0x3b/0x60 [ 418.840490][ C1] Code: 8b 1c 25 c0 1e 02 00 48 8d bb 94 08 00 00 48 89 fa 48 c1 ea 03 0f b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 04 84 d2 75 10 <8b> 93 94 08 00 00 31 c0 5b 5d 85 d2 0f 94 c0 c3 e8 40 8b 51 00 eb [ 418.860684][ C1] RSP: 0018:ffffc90002066ed8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 [ 418.869089][ C1] RAX: 0000000000000007 RBX: ffff88808e400400 RCX: 1ffffffff14f6ffe [ 418.877054][ C1] RDX: 0000000000000000 RSI: ffffffff8676b150 RDI: ffff88808e400c94 [ 418.885044][ C1] RBP: ffffc90002066ee0 R08: 0000000000000001 R09: ffffc90002066f18 [ 418.893000][ C1] R10: fffff5200040cde5 R11: ffffc90002066f2f R12: ffffc90002067040 [ 418.901156][ C1] R13: 00000000bfffffff R14: ffffc90002067020 R15: ffffc90002067020 [ 418.909223][ C1] ? hash_ip4_del+0x20/0xce0 [ 418.913839][ C1] debug_lockdep_rcu_enabled+0x71/0xa0 [ 418.919298][ C1] hash_ip4_del+0x83/0xce0 [ 418.923703][ C1] ? hash_ip4_uadt+0x51e/0x7a0 [ 418.928470][ C1] hash_ip4_uadt+0x546/0x7a0 [ 418.933064][ C1] ? hash_ip6_del+0xe70/0xe70 [ 418.937727][ C1] ? hash_ip6_uadt+0x670/0x670 [ 418.942534][ C1] ? __kasan_check_write+0x14/0x20 [ 418.947714][ C1] call_ad+0x1a0/0x5a0 [ 418.951776][ C1] ? start_msg+0x220/0x220 [ 418.956279][ C1] ? nla_memcpy+0xb0/0xb0 [ 418.960862][ C1] ? __nla_parse+0x43/0x60 [ 418.965337][ C1] ip_set_ad.isra.0+0x572/0xb20 [ 418.970201][ C1] ? ip_set_nfnl_get_byindex+0x460/0x460 [ 418.975833][ C1] ? nla_memcpy+0xb0/0xb0 [ 418.980245][ C1] ? lock_downgrade+0x920/0x920 [ 418.985113][ C1] ip_set_udel+0x3a/0x50 [ 418.989524][ C1] ? ip_set_ad.isra.0+0xb20/0xb20 [ 418.994600][ C1] nfnetlink_rcv_msg+0xcf2/0xfb0 [ 418.999550][ C1] ? nfnetlink_bind+0x2c0/0x2c0 [ 419.004474][ C1] ? __kasan_check_read+0x11/0x20 [ 419.009487][ C1] ? __lock_acquire+0x8a0/0x4a00 [ 419.015478][ C1] ? save_stack+0x5c/0x90 [ 419.019879][ C1] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 419.026162][ C1] ? apparmor_capable+0x497/0x900 [ 419.031234][ C1] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 419.037483][ C1] ? __kasan_check_read+0x11/0x20 [ 419.042510][ C1] ? apparmor_cred_prepare+0x7b0/0x7b0 [ 419.047954][ C1] netlink_rcv_skb+0x177/0x450 [ 419.052749][ C1] ? nfnetlink_bind+0x2c0/0x2c0 [ 419.057596][ C1] ? netlink_ack+0xb50/0xb50 [ 419.062271][ C1] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 419.068552][ C1] ? ns_capable_common+0x93/0x100 [ 419.073640][ C1] ? ns_capable+0x20/0x30 [ 419.077961][ C1] ? __netlink_ns_capable+0x104/0x140 [ 419.083348][ C1] nfnetlink_rcv+0x1ba/0x460 [ 419.087922][ C1] ? nfnetlink_rcv_batch+0x17a0/0x17a0 [ 419.093373][ C1] ? netlink_deliver_tap+0x24a/0xbe0 [ 419.098656][ C1] ? __kasan_check_write+0x14/0x20 [ 419.103757][ C1] netlink_unicast+0x58c/0x7d0 [ 419.108507][ C1] ? netlink_attachskb+0x870/0x870 [ 419.113648][ C1] ? __sanitizer_cov_trace_cmp8+0x18/0x20 [ 419.119410][ C1] ? __check_object_size+0x3d/0x437 [ 419.124620][ C1] netlink_sendmsg+0x91c/0xea0 [ 419.129386][ C1] ? netlink_unicast+0x7d0/0x7d0 [ 419.134381][ C1] ? aa_sock_msg_perm.isra.0+0xba/0x170 [ 419.139955][ C1] ? apparmor_socket_sendmsg+0x2a/0x30 [ 419.145408][ C1] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 419.151727][ C1] ? security_socket_sendmsg+0x8d/0xc0 [ 419.158582][ C1] ? netlink_unicast+0x7d0/0x7d0 [ 419.163609][ C1] sock_sendmsg+0xd7/0x130 [ 419.168033][ C1] ____sys_sendmsg+0x753/0x880 [ 419.172804][ C1] ? kernel_sendmsg+0x50/0x50 [ 419.177490][ C1] ? lockdep_init_map+0x1be/0x6d0 [ 419.182503][ C1] ___sys_sendmsg+0x100/0x170 [ 419.187180][ C1] ? sendmsg_copy_msghdr+0x70/0x70 [ 419.192284][ C1] ? __kasan_check_read+0x11/0x20 [ 419.197319][ C1] ? __lock_acquire+0x8a0/0x4a00 [ 419.202260][ C1] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 419.208542][ C1] ? __this_cpu_preempt_check+0x35/0x190 [ 419.214172][ C1] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 419.220469][ C1] ? percpu_counter_add_batch+0x13c/0x190 [ 419.226217][ C1] ? __fd_install+0x1bc/0x640 [ 419.230951][ C1] ? find_held_lock+0x35/0x130 [ 419.235702][ C1] ? __fd_install+0x1bc/0x640 [ 419.240391][ C1] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 419.246636][ C1] ? __fget_light+0x1a9/0x230 [ 419.251314][ C1] ? __fdget+0x1b/0x20 [ 419.255425][ C1] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 419.261752][ C1] __sys_sendmsg+0x105/0x1d0 [ 419.266332][ C1] ? __sys_sendmsg_sock+0xc0/0xc0 [ 419.271376][ C1] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 419.276833][ C1] ? do_fast_syscall_32+0xd1/0xe16 [ 419.281944][ C1] ? entry_SYSENTER_compat+0x70/0x7f [ 419.287300][ C1] ? do_fast_syscall_32+0xd1/0xe16 [ 419.292456][ C1] __ia32_compat_sys_sendmsg+0x7a/0xb0 [ 419.297954][ C1] do_fast_syscall_32+0x27b/0xe16 [ 419.302983][ C1] entry_SYSENTER_compat+0x70/0x7f [ 419.308126][ C1] RIP: 0023:0xf7fa89a9 [ 419.312180][ C1] Code: 00 00 00 89 d3 5b 5e 5f 5d c3 b8 80 96 98 00 eb c4 8b 04 24 c3 8b 1c 24 c3 8b 34 24 c3 8b 3c 24 c3 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90 [ 419.333184][ C1] RSP: 002b:00000000ffd98fdc EFLAGS: 00000202 ORIG_RAX: 0000000000000172 [ 419.341577][ C1] RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000020000080 [ 419.349545][ C1] RDX: 0000000000000000 RSI: 0000000000000001 RDI: 00000000ffd990f4 [ 419.357635][ C1] RBP: 00000000ffd990fc R08: 0000000000000000 R09: 0000000000000000 [ 419.365649][ C1] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 419.373655][ C1] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000