[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [ 12.487938] random: crng init done Starting mcstransd: [....] 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 '10.128.0.72' (ECDSA) to the list of known hosts. 2019/06/27 06:48:23 parsed 1 programs 2019/06/27 06:48:26 executed programs: 0 syzkaller login: [ 40.142758] audit: type=1400 audit(1561618106.865:5): avc: denied { associate } for pid=2073 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 [ 40.181202] [ 40.182863] =============================== [ 40.187207] [ INFO: suspicious RCU usage. ] [ 40.191511] 4.9.183+ #4 Not tainted [ 40.195263] ------------------------------- [ 40.199573] ./include/linux/inetdevice.h:205 suspicious rcu_dereference_check() usage! [ 40.207692] [ 40.207692] other info that might help us debug this: [ 40.207692] [ 40.215869] [ 40.215869] rcu_scheduler_active = 2, debug_locks = 0 [ 40.222533] 4 locks held by syz-executor.0/2221: [ 40.227395] #0: (rcu_read_lock_bh){......}, at: [<00000000be23ab40>] ip_finish_output2+0x20b/0x1280 [ 40.237300] #1: (rcu_read_lock_bh){......}, at: [<00000000e895d080>] __dev_queue_xmit+0x1d4/0x1bd0 [ 40.247478] #2: (_xmit_TUNNEL6#2){+.....}, at: [<000000000d572db6>] __dev_queue_xmit+0x1116/0x1bd0 [ 40.257682] #3: (slock-AF_INET){+.-...}, at: [<00000000128bf208>] __icmp_send+0x48b/0x1420 [ 40.266835] [ 40.266835] stack backtrace: [ 40.271328] CPU: 1 PID: 2221 Comm: syz-executor.0 Not tainted 4.9.183+ #4 [ 40.278247] ffff8801cb896dd8 ffffffff81b580a1 ffff8801cefb8a00 0000000000000000 [ 40.286255] 0000000000000002 00000000000000cd ffff8801cc9edf00 ffff8801cb896e08 [ 40.294393] ffffffff81404fb9 ffff8801cefb8a58 ffff8801cb896f28 ffff8801ce616600 [ 40.302411] Call Trace: [ 40.304986] [<00000000c8cfeb98>] dump_stack+0xc1/0x120 [ 40.310401] [<0000000072a14f11>] lockdep_rcu_suspicious.cold+0x10a/0x149 [ 40.317337] [<00000000657b9638>] fib_compute_spec_dst+0x6c4/0xcc0 [ 40.323653] [<0000000046e19554>] ? fib_unmerge+0x4c0/0x4c0 [ 40.329474] [<0000000067442857>] ? trace_hardirqs_on+0x10/0x10 [ 40.335522] [<000000002337113c>] ? __lock_acquire+0x5e5/0x4350 [ 40.341682] [<0000000050c9e8b9>] __ip_options_echo+0x4be/0x13e0 [ 40.347846] [<000000009beb9c0a>] __icmp_send+0x648/0x1420 [ 40.353806] [<000000000a11d05d>] ? __icmp_send+0xc07/0x1420 [ 40.359607] [<000000002337113c>] ? __lock_acquire+0x5e5/0x4350 [ 40.365661] [<000000005db07297>] ? icmpv4_xrlim_allow.isra.0+0x2d0/0x2d0 [ 40.372575] [<0000000067442857>] ? trace_hardirqs_on+0x10/0x10 [ 40.378672] [<00000000a2c9df30>] ? debug_lockdep_rcu_enabled+0x71/0xa0 [ 40.385417] [<0000000051750d26>] ? __ip_options_compile+0x668/0x13c0 [ 40.391983] [<000000007311023f>] ? check_preemption_disabled+0x3c/0x200 [ 40.398803] [<0000000095dc317a>] ? ipv4_link_failure+0x410/0x850 [ 40.405009] [<00000000ac6b67da>] ipv4_link_failure+0x460/0x850 [ 40.411104] [<00000000581cedd6>] ? ipv4_link_failure+0x32b/0x850 [ 40.417737] [<0000000049d28da0>] ? rt_dst_alloc+0x450/0x450 [ 40.423524] [<0000000049d28da0>] ? rt_dst_alloc+0x450/0x450 [ 40.429364] [<000000009f7b3d2c>] vti6_tnl_xmit+0xb08/0x17f0 [ 40.435205] [<00000000b216dcc6>] ? vti6_dellink+0x270/0x270 [ 40.441006] [<000000002b4591f8>] dev_hard_start_xmit+0x195/0x8b0 [ 40.447236] [<000000008189cea6>] __dev_queue_xmit+0x11a3/0x1bd0 [ 40.453380] [<00000000e895d080>] ? __dev_queue_xmit+0x1d4/0x1bd0 [ 40.459609] [<00000000e2fe6e2d>] ? __local_bh_enable_ip+0x6a/0xe0 [ 40.466061] [<0000000042dac443>] ? netdev_pick_tx+0x300/0x300 [ 40.472034] [<000000005c3e7dc4>] ? __neigh_create+0x96e/0x1b30 [ 40.478136] [<00000000b69b5059>] dev_queue_xmit+0x18/0x20 [ 40.483799] [<00000000ecf78c6d>] neigh_direct_output+0x16/0x20 [ 40.489935] [<000000005c676708>] ip_finish_output2+0x6a2/0x1280 [ 40.496229] [<00000000be23ab40>] ? ip_finish_output2+0x20b/0x1280 [ 40.502629] [<000000003e785711>] ? rcu_read_lock_held+0x9e/0xc0 [ 40.508896] [<00000000a0ca8c02>] ? nf_iterate+0x19e/0x310 [ 40.514596] [<0000000083218b57>] ? ip_send_check+0xb0/0xb0 [ 40.520379] [<00000000a2c9df30>] ? debug_lockdep_rcu_enabled+0x71/0xa0 [ 40.527156] [<00000000ab70ddc9>] ? nf_hook_slow+0x12f/0x1f0 [ 40.533112] [<0000000051dd6bae>] ip_finish_output+0x3c4/0xce0 [ 40.539282] [<0000000089092b3a>] ip_output+0x1ec/0x5b0 [ 40.544652] [<000000001b472059>] ? ip_output+0x287/0x5b0 [ 40.550269] [<000000004e1bf9a7>] ? ip_mc_output+0xcb0/0xcb0 [ 40.556309] [<00000000db349519>] ? nf_hook_slow+0x62/0x1f0 [ 40.562026] [<00000000992ae37c>] ? ip_fragment.constprop.0+0x210/0x210 [ 40.568842] [<000000007311023f>] ? check_preemption_disabled+0x3c/0x200 [ 40.575698] [<00000000b9764845>] ? raw_sendmsg+0x1929/0x23e0 [ 40.581603] [<00000000b240b062>] raw_sendmsg+0x1c5c/0x23e0 [ 40.589396] [<00000000f73b1834>] ? raw_sendmsg+0x1851/0x23e0 [ 40.595667] [<00000000b7e7b29e>] ? avc_has_perm+0x164/0x3a0 [ 40.601482] [<00000000091113d0>] ? compat_raw_setsockopt+0xd0/0xd0 [ 40.607956] [<000000002337113c>] ? __lock_acquire+0x5e5/0x4350 [ 40.614033] [<00000000a2c9df30>] ? debug_lockdep_rcu_enabled+0x71/0xa0 [ 40.620803] [<000000007311023f>] ? check_preemption_disabled+0x3c/0x200 [ 40.627652] [<0000000065be9133>] ? trace_hardirqs_on_caller+0x4f2/0x5a0 [ 40.634607] [<000000003191fc6a>] ? ip4_datagram_release_cb+0x970/0x970 [ 40.641374] [<00000000501da100>] ? selinux_msg_queue_alloc_security+0x2e0/0x2e0 [ 40.649053] [<00000000a2c9df30>] ? debug_lockdep_rcu_enabled+0x71/0xa0 [ 40.655823] [<000000007311023f>] ? check_preemption_disabled+0x3c/0x200 [ 40.662716] [<000000007311023f>] ? check_preemption_disabled+0x3c/0x200 [ 40.669563] [<000000007311023f>] ? check_preemption_disabled+0x3c/0x200 [ 40.676514] [<0000000079e9f1a5>] ? inet_sendmsg+0x143/0x4d0 [ 40.682311] [<00000000ff78ee20>] inet_sendmsg+0x202/0x4d0 [ 40.688108] [<000000002be5f74b>] ? inet_sendmsg+0x76/0x4d0 [ 40.693819] [<00000000fa207e0b>] ? inet_recvmsg+0x4d0/0x4d0 [ 40.699622] [<00000000c99c29d5>] sock_sendmsg+0xbe/0x110 [ 40.705161] [<00000000c123d96a>] sock_write_iter+0x235/0x3d0 [ 40.711380] [<00000000d19830dd>] ? sock_sendmsg+0x110/0x110 [ 40.717228] [<00000000ddbd4314>] ? iov_iter_init+0xaf/0x1d0 [ 40.723035] [<00000000bbd0c32f>] __vfs_write+0x3c1/0x560 [ 40.728568] [<000000003dcfb4f2>] ? bpf_fd_pass+0x270/0x270 [ 40.734270] [<0000000003dbc995>] ? __vfs_read+0x550/0x550 [ 40.739885] [<000000007fed4f0f>] ? trace_hardirqs_on+0xd/0x10 [ 40.745960] [<00000000b6fb2379>] ? selinux_file_permission+0x85/0x470 [ 40.752637] [<0000000006369cf4>] ? security_file_permission+0x8f/0x1f0 [ 40.759387] [<00000000ee43b2a6>] ? rw_verify_area+0xea/0x2b0 [ 40.765360] [<000000001a041c74>] vfs_write+0x185/0x520 [ 40.770710] [<000000004adad496>] SyS_write+0x121/0x270 [ 40.776145] [<00000000d751eaf7>] ? SyS_read+0x270/0x270 [ 40.781592] [<00000000d8c44608>] ? do_syscall_64+0x4a/0x5c0 [ 40.787386] [<00000000d751eaf7>] ? SyS_read+0x270/0x270 [ 40.792834] [<000000002117715a>