[?25l[?1c7[ ok 8[?25h[?0c. [ 11.174407] random: crng init done Starting mcstransd: [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting file context maintaining daemon: restorecond[?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 '10.128.0.213' (ECDSA) to the list of known hosts. 2019/06/27 09:17:11 parsed 1 programs 2019/06/27 09:17:13 executed programs: 0 syzkaller login: [ 39.931799] audit: type=1400 audit(1561627034.412:5): avc: denied { associate } for pid=2077 comm="syz-executor.0" name="syz0" scontext=unconfined_u:object_r:unlabeled_t:s0 tcontext=system_u:object_r:unlabeled_t:s0 tclass=filesystem permissive=1 [ 39.968660] [ 39.970331] =============================== [ 39.974639] [ INFO: suspicious RCU usage. ] [ 39.978979] 4.9.183+ #4 Not tainted [ 39.982616] ------------------------------- [ 39.986963] ./include/linux/inetdevice.h:205 suspicious rcu_dereference_check() usage! [ 39.995009] [ 39.995009] other info that might help us debug this: [ 39.995009] [ 40.003179] [ 40.003179] rcu_scheduler_active = 2, debug_locks = 0 [ 40.009969] 4 locks held by syz-executor.0/2226: [ 40.014703] #0: (rcu_read_lock_bh){......}, at: [<000000005e5f3ab9>] ip_finish_output2+0x20b/0x1280 [ 40.024680] #1: (rcu_read_lock_bh){......}, at: [<000000008a9faec2>] __dev_queue_xmit+0x1d4/0x1bd0 [ 40.034486] #2: (_xmit_TUNNEL6#2){+.....}, at: [<0000000017c61160>] __dev_queue_xmit+0x1116/0x1bd0 [ 40.044415] #3: (slock-AF_INET){+.-...}, at: [<0000000035011760>] __icmp_send+0x48b/0x1420 [ 40.053721] [ 40.053721] stack backtrace: [ 40.058242] CPU: 1 PID: 2226 Comm: syz-executor.0 Not tainted 4.9.183+ #4 [ 40.065170] ffff8801cb846dd8 ffffffff81b580a1 ffff8801cf193140 0000000000000000 [ 40.073316] 0000000000000002 00000000000000cd ffff8801cc18c740 ffff8801cb846e08 [ 40.081322] ffffffff81404fb9 ffff8801cf193198 ffff8801cb846f28 ffff8801d9cfb300 [ 40.089342] Call Trace: [ 40.091915] [<0000000032891a1a>] dump_stack+0xc1/0x120 [ 40.097266] [<00000000de93bee9>] lockdep_rcu_suspicious.cold+0x10a/0x149 [ 40.104180] [<00000000955d14ca>] fib_compute_spec_dst+0x6c4/0xcc0 [ 40.110480] [<00000000fc4bb5fe>] ? fib_unmerge+0x4c0/0x4c0 [ 40.116173] [<00000000feb82a64>] ? trace_hardirqs_on+0x10/0x10 [ 40.122207] [<00000000a8fd6193>] ? __lock_acquire+0x5e5/0x4350 [ 40.128248] [<000000009970b2ee>] __ip_options_echo+0x4be/0x13e0 [ 40.134389] [<0000000027989a0b>] __icmp_send+0x648/0x1420 [ 40.139993] [<000000003f29d37a>] ? __icmp_send+0xc07/0x1420 [ 40.145882] [<00000000a8fd6193>] ? __lock_acquire+0x5e5/0x4350 [ 40.151929] [<00000000070d14e1>] ? icmpv4_xrlim_allow.isra.0+0x2d0/0x2d0 [ 40.158836] [<00000000feb82a64>] ? trace_hardirqs_on+0x10/0x10 [ 40.164875] [<0000000017f71c40>] ? debug_lockdep_rcu_enabled+0x71/0xa0 [ 40.171731] [<0000000008d6ee7c>] ? __ip_options_compile+0x668/0x13c0 [ 40.178301] [<0000000084e76165>] ? check_preemption_disabled+0x3c/0x200 [ 40.185174] [<000000000dc84fc7>] ? ipv4_link_failure+0x410/0x850 [ 40.191407] [<000000001d8920c9>] ipv4_link_failure+0x460/0x850 [ 40.197456] [<000000000a2369c5>] ? ipv4_link_failure+0x32b/0x850 [ 40.203675] [<000000004c618a6c>] ? rt_dst_alloc+0x450/0x450 [ 40.209828] [<000000004c618a6c>] ? rt_dst_alloc+0x450/0x450 [ 40.215615] [<0000000097650b48>] vti6_tnl_xmit+0xb08/0x17f0 [ 40.221441] [<0000000083fbe4d8>] ? vti6_dellink+0x270/0x270 [ 40.227230] [<00000000e55ed975>] dev_hard_start_xmit+0x195/0x8b0 [ 40.233563] [<00000000a8488050>] __dev_queue_xmit+0x11a3/0x1bd0 [ 40.239688] [<000000008a9faec2>] ? __dev_queue_xmit+0x1d4/0x1bd0 [ 40.245903] [<00000000945f6e1b>] ? __local_bh_enable_ip+0x6a/0xe0 [ 40.252204] [<0000000041f0f0db>] ? netdev_pick_tx+0x300/0x300 [ 40.258158] [<00000000a0e20eab>] ? __neigh_create+0x96e/0x1b30 [ 40.264386] [<00000000c169a100>] dev_queue_xmit+0x18/0x20 [ 40.270040] [<00000000ce8eed2e>] neigh_direct_output+0x16/0x20 [ 40.276230] [<000000009afa5adc>] ip_finish_output2+0x6a2/0x1280 [ 40.282358] [<000000005e5f3ab9>] ? ip_finish_output2+0x20b/0x1280 [ 40.288661] [<00000000690b9102>] ? rcu_read_lock_held+0x9e/0xc0 [ 40.294788] [<000000006a3ee805>] ? nf_iterate+0x19e/0x310 [ 40.300392] [<0000000036577cce>] ? ip_send_check+0xb0/0xb0 [ 40.306260] [<0000000017f71c40>] ? debug_lockdep_rcu_enabled+0x71/0xa0 [ 40.313004] [<00000000d40643b1>] ? nf_hook_slow+0x12f/0x1f0 [ 40.318801] [<0000000023f272ea>] ip_finish_output+0x3c4/0xce0 [ 40.324775] [<00000000cd211485>] ip_output+0x1ec/0x5b0 [ 40.330217] [<000000007f35e8be>] ? ip_output+0x287/0x5b0 [ 40.335740] [<00000000c34d5405>] ? ip_mc_output+0xcb0/0xcb0 [ 40.341649] [<0000000023afc723>] ? nf_hook_slow+0x62/0x1f0 [ 40.347421] [<00000000fc5b70f9>] ? ip_fragment.constprop.0+0x210/0x210 [ 40.354182] [<0000000084e76165>] ? check_preemption_disabled+0x3c/0x200 [ 40.361217] [<00000000eac252cb>] ? raw_sendmsg+0x1929/0x23e0 [ 40.367190] [<0000000078e148fa>] raw_sendmsg+0x1c5c/0x23e0 [ 40.372889] [<00000000ef1bdfb3>] ? raw_sendmsg+0x1851/0x23e0 [ 40.378867] [<00000000d2898426>] ? avc_has_perm+0x164/0x3a0 [ 40.384709] [<00000000253c8505>] ? compat_raw_setsockopt+0xd0/0xd0 [ 40.391201] [<00000000a8fd6193>] ? __lock_acquire+0x5e5/0x4350 [ 40.397246] [<0000000017f71c40>] ? debug_lockdep_rcu_enabled+0x71/0xa0 [ 40.404403] [<0000000084e76165>] ? check_preemption_disabled+0x3c/0x200 [ 40.411242] [<0000000012e7cec2>] ? trace_hardirqs_on_caller+0x4f2/0x5a0 [ 40.418128] [<000000000be07e47>] ? ip4_datagram_release_cb+0x970/0x970 [ 40.424987] [<000000008c0c1898>] ? selinux_msg_queue_alloc_security+0x2e0/0x2e0 [ 40.432504] [<0000000017f71c40>] ? debug_lockdep_rcu_enabled+0x71/0xa0 [ 40.439243] [<0000000084e76165>] ? check_preemption_disabled+0x3c/0x200 [ 40.446069] [<0000000084e76165>] ? check_preemption_disabled+0x3c/0x200 [ 40.452945] [<0000000084e76165>] ? check_preemption_disabled+0x3c/0x200 [ 40.459829] [<00000000fb0dbf39>] ? inet_sendmsg+0x143/0x4d0 [ 40.465844] [<00000000fb798714>] inet_sendmsg+0x202/0x4d0 [ 40.471543] [<00000000747e8f96>] ? inet_sendmsg+0x76/0x4d0 [ 40.477251] [<00000000facfad9b>] ? inet_recvmsg+0x4d0/0x4d0 [ 40.483194] [<000000006615f524>] sock_sendmsg+0xbe/0x110 [ 40.488901] [<000000005dee7e2f>] sock_write_iter+0x235/0x3d0 [ 40.494823] [<0000000039f33316>] ? sock_sendmsg+0x110/0x110 [ 40.500630] [<00000000bab94135>] ? iov_iter_init+0xaf/0x1d0 [ 40.506412] [<00000000965aaee1>] __vfs_write+0x3c1/0x560 [ 40.511934] [<000000003673010c>] ? bpf_fd_pass+0x270/0x270 [ 40.517630] [<00000000599bd3b9>] ? __vfs_read+0x550/0x550 [ 40.523413] [<00000000d7e4640b>] ? trace_hardirqs_on+0xd/0x10 [ 40.529375] [<000000003b290aa3>] ? selinux_file_permission+0x85/0x470 [ 40.536153] [<000000000f496ba3>] ? security_file_permission+0x8f/0x1f0 [ 40.542897] [<0000000009d356ad>] ? rw_verify_area+0xea/0x2b0 [ 40.548768] [<00000000ab805e5a>] vfs_write+0x185/0x520 [ 40.554124] [<000000001e992bb9>] SyS_write+0x121/0x270 [ 40.559469] [<0000000051a72b14>] ? SyS_read+0x270/0x270 [ 40.564998] [<00000000d8bde165>] ? do_syscall_64+0x4a/0x5c0 [ 40.571037] [<0000000051a72b14>] ? SyS_read+0x270/0x270 [ 40.576466] [<000000002ec17da2>] do_syscall_64+0x1ad/0x5c0 [ 40.582344] [<0000000016