[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [ 11.515359] 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 '10.128.0.216' (ECDSA) to the list of known hosts. 2019/06/27 08:55:51 parsed 1 programs 2019/06/27 08:55:53 executed programs: 0 syzkaller login: [ 50.993219] audit: type=1400 audit(1561625753.704:5): avc: denied { associate } for pid=2087 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 [ 51.011692] [ 51.012074] =============================== [ 51.012838] [ INFO: suspicious RCU usage. ] [ 51.013638] 4.9.183+ #4 Not tainted [ 51.017287] ------------------------------- [ 51.021593] ./include/linux/inetdevice.h:205 suspicious rcu_dereference_check() usage! [ 51.029680] [ 51.029680] other info that might help us debug this: [ 51.029680] [ 51.037840] [ 51.037840] rcu_scheduler_active = 2, debug_locks = 0 [ 51.044496] 4 locks held by syz-executor.0/2236: [ 51.049397] #0: (rcu_read_lock_bh){......}, at: [<0000000080805da0>] ip_finish_output2+0x20b/0x1280 [ 51.059324] #1: (rcu_read_lock_bh){......}, at: [<0000000013f25c8f>] __dev_queue_xmit+0x1d4/0x1bd0 [ 51.071168] #2: (_xmit_TUNNEL6#2){+.....}, at: [<0000000010282f2a>] __dev_queue_xmit+0x1116/0x1bd0 [ 51.081121] #3: (slock-AF_INET){+.-...}, at: [<00000000a809ce4a>] __icmp_send+0x48b/0x1420 [ 51.090311] [ 51.090311] stack backtrace: [ 51.094793] CPU: 1 PID: 2236 Comm: syz-executor.0 Not tainted 4.9.183+ #4 [ 51.101709] ffff8801c94eedd8 ffffffff81b580a1 ffff8801d247a280 0000000000000000 [ 51.118433] 0000000000000002 00000000000000cd ffff8801c99bdf00 ffff8801c94eee08 [ 51.126635] ffffffff81404fb9 ffff8801d247a2d8 ffff8801c94eef28 ffff8801d9d00000 [ 51.134652] Call Trace: [ 51.137230] [<00000000af2d3c1e>] dump_stack+0xc1/0x120 [ 51.142592] [<00000000f839f91c>] lockdep_rcu_suspicious.cold+0x10a/0x149 [ 51.149517] [<0000000029b35d6d>] fib_compute_spec_dst+0x6c4/0xcc0 [ 51.155881] [<000000000b6281bf>] ? fib_unmerge+0x4c0/0x4c0 [ 51.161591] [<000000008cb2a40a>] ? trace_hardirqs_on+0x10/0x10 [ 51.167640] [<00000000c3455782>] ? __lock_acquire+0x5e5/0x4350 [ 51.173716] [<000000000074e817>] __ip_options_echo+0x4be/0x13e0 [ 51.179916] [<0000000028bcfd0d>] __icmp_send+0x648/0x1420 [ 51.185634] [<0000000081e81f0d>] ? __icmp_send+0xc07/0x1420 [ 51.192124] [<00000000c3455782>] ? __lock_acquire+0x5e5/0x4350 [ 51.198176] [<000000008b33cf43>] ? icmpv4_xrlim_allow.isra.0+0x2d0/0x2d0 [ 51.205099] [<000000008cb2a40a>] ? trace_hardirqs_on+0x10/0x10 [ 51.211187] [<00000000f9d085f2>] ? debug_lockdep_rcu_enabled+0x71/0xa0 [ 51.217937] [<000000006d8e919f>] ? __ip_options_compile+0x668/0x13c0 [ 51.224519] [<000000003091930b>] ? check_preemption_disabled+0x3c/0x200 [ 51.231360] [<000000007d53b56c>] ? ipv4_link_failure+0x410/0x850 [ 51.237589] [<00000000fbf33dd1>] ipv4_link_failure+0x460/0x850 [ 51.243818] [<00000000f3e6be44>] ? ipv4_link_failure+0x32b/0x850 [ 51.250043] [<00000000a51dcd60>] ? rt_dst_alloc+0x450/0x450 [ 51.255835] [<00000000a51dcd60>] ? rt_dst_alloc+0x450/0x450 [ 51.261700] [<00000000f0571047>] vti6_tnl_xmit+0xb08/0x17f0 [ 51.267494] [<00000000a307998e>] ? vti6_dellink+0x270/0x270 [ 51.273277] [<00000000387bfaa2>] dev_hard_start_xmit+0x195/0x8b0 [ 51.279518] [<00000000d826ecf0>] __dev_queue_xmit+0x11a3/0x1bd0 [ 51.285916] [<0000000013f25c8f>] ? __dev_queue_xmit+0x1d4/0x1bd0 [ 51.292139] [<00000000a06ce9b2>] ? __local_bh_enable_ip+0x6a/0xe0 [ 51.298457] [<00000000b60432ab>] ? netdev_pick_tx+0x300/0x300 [ 51.304427] [<0000000064fd120a>] ? __neigh_create+0x96e/0x1b30 [ 51.310475] [<00000000c46e8337>] dev_queue_xmit+0x18/0x20 [ 51.316090] [<00000000ee6f5d53>] neigh_direct_output+0x16/0x20 [ 51.322462] [<00000000ba2cf7c8>] ip_finish_output2+0x6a2/0x1280 [ 51.328598] [<0000000080805da0>] ? ip_finish_output2+0x20b/0x1280 [ 51.334910] [<00000000f113f983>] ? rcu_read_lock_held+0x9e/0xc0 [ 51.341142] [<00000000d47c2427>] ? nf_iterate+0x19e/0x310 [ 51.346761] [<000000001cc58f61>] ? ip_send_check+0xb0/0xb0 [ 51.352468] [<00000000f9d085f2>] ? debug_lockdep_rcu_enabled+0x71/0xa0 [ 51.359215] [<000000003f93ebd5>] ? nf_hook_slow+0x12f/0x1f0 [ 51.364999] [<00000000694bfc6a>] ip_finish_output+0x3c4/0xce0 [ 51.371010] [<00000000400a4c9a>] ip_output+0x1ec/0x5b0 [ 51.376375] [<000000006f222839>] ? ip_output+0x287/0x5b0 [ 51.381913] [<000000003ee13685>] ? ip_mc_output+0xcb0/0xcb0 [ 51.387925] [<000000008c77853f>] ? nf_hook_slow+0x62/0x1f0 [ 51.393695] [<000000001d5bcc9f>] ? ip_fragment.constprop.0+0x210/0x210 [ 51.400450] [<000000003091930b>] ? check_preemption_disabled+0x3c/0x200 [ 51.407279] [<000000007ccf6113>] ? raw_sendmsg+0x1929/0x23e0 [ 51.413157] [<0000000049b9c9a9>] raw_sendmsg+0x1c5c/0x23e0 [ 51.418918] [<00000000b5b8524a>] ? raw_sendmsg+0x1851/0x23e0 [ 51.426048] [<000000004e2fbe2d>] ? avc_has_perm+0x164/0x3a0 [ 51.431849] [<0000000008840646>] ? compat_raw_setsockopt+0xd0/0xd0 [ 51.438251] [<00000000c3455782>] ? __lock_acquire+0x5e5/0x4350 [ 51.444301] [<00000000f9d085f2>] ? debug_lockdep_rcu_enabled+0x71/0xa0 [ 51.451053] [<000000003091930b>] ? check_preemption_disabled+0x3c/0x200 [ 51.457893] [<00000000f0416ede>] ? trace_hardirqs_on_caller+0x4f2/0x5a0 [ 51.464730] [<00000000eae9d342>] ? ip4_datagram_release_cb+0x970/0x970 [ 51.471474] [<000000009b227b73>] ? selinux_msg_queue_alloc_security+0x2e0/0x2e0 [ 51.479044] [<00000000f9d085f2>] ? debug_lockdep_rcu_enabled+0x71/0xa0 [ 51.485793] [<000000003091930b>] ? check_preemption_disabled+0x3c/0x200 [ 51.492624] [<000000003091930b>] ? check_preemption_disabled+0x3c/0x200 [ 51.499487] [<000000003091930b>] ? check_preemption_disabled+0x3c/0x200 [ 51.506358] [<000000000a2532d0>] ? inet_sendmsg+0x143/0x4d0 [ 51.512151] [<000000003461f6c0>] inet_sendmsg+0x202/0x4d0 [ 51.517761] [<0000000052413375>] ? inet_sendmsg+0x76/0x4d0 [ 51.523572] [<000000009e5519f5>] ? inet_recvmsg+0x4d0/0x4d0 [ 51.529362] [<000000008b22d16e>] sock_sendmsg+0xbe/0x110 [ 51.534896] [<00000000640ebbdd>] sock_write_iter+0x235/0x3d0 [ 51.540773] [<000000008d7197f4>] ? sock_sendmsg+0x110/0x110 [ 51.546649] [<00000000694428c3>] ? iov_iter_init+0xaf/0x1d0 [ 51.552441] [<000000008df9ff7c>] __vfs_write+0x3c1/0x560 [ 51.558075] [<000000009747c068>] ? bpf_fd_pass+0x270/0x270 [ 51.563785] [<000000004943ad64>] ? __vfs_read+0x550/0x550 [ 51.569400] [<00000000cfcc6083>] ? trace_hardirqs_on+0xd/0x10 [ 51.575355] [<00000000f19eceee>] ? selinux_file_permission+0x85/0x470 [ 51.582006] [<000000001f74dbcb>] ? security_file_permission+0x8f/0x1f0 [ 51.588951] [<0000000035295584>] ? rw_verify_area+0xea/0x2b0 [ 51.594882]