[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. Starting mcstransd: [....] Starting file context maintaining daemon: restorecond[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 11.720720] random: crng init done [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.0.141' (ECDSA) to the list of known hosts. 2019/06/21 15:11:27 parsed 1 programs 2019/06/21 15:11:29 executed programs: 0 syzkaller login: [ 41.088484] audit: type=1400 audit(1561129889.559:5): 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 [ 41.105709] [ 41.106078] =============================== [ 41.106912] [ INFO: suspicious RCU usage. ] [ 41.107734] 4.9.182+ #2 Not tainted [ 41.108500] ------------------------------- [ 41.112164] ./include/linux/inetdevice.h:205 suspicious rcu_dereference_check() usage! [ 41.120224] [ 41.120224] other info that might help us debug this: [ 41.120224] [ 41.128373] [ 41.128373] rcu_scheduler_active = 2, debug_locks = 0 [ 41.135041] 4 locks held by syz-executor.0/2225: [ 41.139779] #0: (rcu_read_lock_bh){......}, at: [<000000001e09b893>] ip_finish_output2+0x20b/0x1280 [ 41.149709] #1: (rcu_read_lock_bh){......}, at: [<000000003c164104>] __dev_queue_xmit+0x1d4/0x1bd0 [ 41.159737] #2: (_xmit_TUNNEL6#2){+.....}, at: [<00000000e741b536>] __dev_queue_xmit+0x1116/0x1bd0 [ 41.169780] #3: (slock-AF_INET){+.-...}, at: [<000000004c3cddfd>] __icmp_send+0x48b/0x1420 [ 41.178879] [ 41.178879] stack backtrace: [ 41.183357] CPU: 1 PID: 2225 Comm: syz-executor.0 Not tainted 4.9.182+ #2 [ 41.190280] ffff8801c9326dd8 ffffffff81b57e21 ffff8801d29763c0 0000000000000000 [ 41.198400] 0000000000000002 00000000000000cd ffff8801c90e4740 ffff8801c9326e08 [ 41.206414] ffffffff81404f19 ffff8801d2976418 ffff8801c9326f28 ffff8801d9cf9100 [ 41.214415] Call Trace: [ 41.216984] [<00000000a37d1489>] dump_stack+0xc1/0x120 [ 41.222325] [<00000000949d8a25>] lockdep_rcu_suspicious.cold+0x10a/0x149 [ 41.229408] [<000000004f602e1f>] fib_compute_spec_dst+0x6c4/0xcc0 [ 41.235889] [<000000008f9ebf23>] ? fib_unmerge+0x4c0/0x4c0 [ 41.241582] [<0000000072d71713>] ? trace_hardirqs_on+0x10/0x10 [ 41.247623] [<0000000044caf4a8>] ? check_preemption_disabled+0x3c/0x200 [ 41.254536] [<0000000044caf4a8>] ? check_preemption_disabled+0x3c/0x200 [ 41.261370] [<000000002808c59c>] __ip_options_echo+0x4be/0x13e0 [ 41.267491] [<00000000a8577151>] __icmp_send+0x648/0x1420 [ 41.273094] [<0000000079b8af50>] ? __icmp_send+0xc07/0x1420 [ 41.278883] [<0000000045039566>] ? __lock_acquire+0x5e5/0x4350 [ 41.284925] [<000000007a2b2f71>] ? icmpv4_xrlim_allow.isra.0+0x2d0/0x2d0 [ 41.291926] [<0000000072d71713>] ? trace_hardirqs_on+0x10/0x10 [ 41.298049] [<00000000d1ce5587>] ? debug_lockdep_rcu_enabled+0x71/0xa0 [ 41.304781] [<000000000b537ebd>] ? __ip_options_compile+0x668/0x13c0 [ 41.311356] [<0000000044caf4a8>] ? check_preemption_disabled+0x3c/0x200 [ 41.318190] [<00000000a341dacb>] ? ipv4_link_failure+0x410/0x850 [ 41.324397] [<0000000051a0ef7c>] ipv4_link_failure+0x460/0x850 [ 41.330432] [<0000000054601bec>] ? ipv4_link_failure+0x32b/0x850 [ 41.336644] [<000000003ea1abd2>] ? rt_dst_alloc+0x450/0x450 [ 41.342422] [<000000003ea1abd2>] ? rt_dst_alloc+0x450/0x450 [ 41.348285] [<000000007ab13ec0>] vti6_tnl_xmit+0xb08/0x17f0 [ 41.354059] [<00000000bb74820e>] ? vti6_dellink+0x270/0x270 [ 41.361918] [<00000000b95a2f98>] dev_hard_start_xmit+0x195/0x8b0 [ 41.368128] [<0000000046e0c47c>] __dev_queue_xmit+0x11a3/0x1bd0 [ 41.374265] [<000000003c164104>] ? __dev_queue_xmit+0x1d4/0x1bd0 [ 41.380495] [<000000003a5bdaf2>] ? __local_bh_enable_ip+0x6a/0xe0 [ 41.386795] [<000000004d8fe61d>] ? netdev_pick_tx+0x300/0x300 [ 41.392741] [<00000000fd96f7d1>] ? __neigh_create+0x96e/0x1b30 [ 41.398795] [<000000009550bb77>] dev_queue_xmit+0x18/0x20 [ 41.404397] [<0000000005340e43>] neigh_direct_output+0x16/0x20 [ 41.410432] [<000000005121b0a3>] ip_finish_output2+0x6a2/0x1280 [ 41.416651] [<000000001e09b893>] ? ip_finish_output2+0x20b/0x1280 [ 41.422952] [<000000001aacea57>] ? rcu_read_lock_held+0x9e/0xc0 [ 41.429485] [<0000000036c006c8>] ? nf_iterate+0x19e/0x310 [ 41.435813] [<00000000b8f8fcc8>] ? ip_send_check+0xb0/0xb0 [ 41.441801] [<00000000d1ce5587>] ? debug_lockdep_rcu_enabled+0x71/0xa0 [ 41.448533] [<000000003b2dbfdf>] ? nf_hook_slow+0x12f/0x1f0 [ 41.454315] [<000000007e749fa5>] ip_finish_output+0x3c4/0xce0 [ 41.460268] [<00000000f6c1e3c2>] ip_output+0x1ec/0x5b0 [ 41.465609] [<00000000492ca396>] ? ip_output+0x287/0x5b0 [ 41.471141] [<00000000d5c7bf35>] ? ip_mc_output+0xcb0/0xcb0 [ 41.476928] [<000000003053dcbe>] ? nf_hook_slow+0x72/0x1f0 [ 41.482621] [<0000000006abcd14>] ? ip_fragment.constprop.0+0x210/0x210 [ 41.489352] [<0000000044caf4a8>] ? check_preemption_disabled+0x3c/0x200 [ 41.496170] [<0000000053a2b1fd>] ? raw_sendmsg+0x1929/0x23e0 [ 41.502030] [<00000000b29f358a>] raw_sendmsg+0x1c5c/0x23e0 [ 41.507717] [<000000001c688941>] ? raw_sendmsg+0x1851/0x23e0 [ 41.513583] [<00000000a07d1a02>] ? avc_has_perm+0x164/0x3a0 [ 41.519356] [<00000000a2f1db53>] ? compat_raw_setsockopt+0xd0/0xd0 [ 41.527260] [<0000000045039566>] ? __lock_acquire+0x5e5/0x4350 [ 41.533296] [<00000000d1ce5587>] ? debug_lockdep_rcu_enabled+0x71/0xa0 [ 41.540028] [<0000000044caf4a8>] ? check_preemption_disabled+0x3c/0x200 [ 41.546863] [<000000006daa121a>] ? trace_hardirqs_on_caller+0x4c2/0x5a0 [ 41.553684] [<00000000c6bb48c0>] ? ip4_datagram_release_cb+0x970/0x970 [ 41.560431] [<0000000001c131d6>] ? selinux_msg_queue_alloc_security+0x2e0/0x2e0 [ 41.567966] [<00000000d1ce5587>] ? debug_lockdep_rcu_enabled+0x71/0xa0 [ 41.574705] [<0000000044caf4a8>] ? check_preemption_disabled+0x3c/0x200 [ 41.581534] [<0000000044caf4a8>] ? check_preemption_disabled+0x3c/0x200 [ 41.588357] [<0000000044caf4a8>] ? check_preemption_disabled+0x3c/0x200 [ 41.595171] [<0000000027a98b9c>] ? inet_sendmsg+0x143/0x4d0 [ 41.600945] [<0000000080a4c7c7>] inet_sendmsg+0x202/0x4d0 [ 41.606563] [<0000000062482a19>] ? inet_sendmsg+0x76/0x4d0 [ 41.612251] [<000000006d5ff5dc>] ? inet_recvmsg+0x4d0/0x4d0 [ 41.618029] [<0000000046bdb5ad>] sock_sendmsg+0xbe/0x110 [ 41.623541] [<00000000b1645b83>] sock_write_iter+0x235/0x3d0 [ 41.629399] [<000000009b22a2d2>] ? sock_sendmsg+0x110/0x110 [ 41.635171] [<0000000009bbd586>] ? iov_iter_init+0xaf/0x1d0 [ 41.640948] [<000000005380afff>] __vfs_write+0x3c1/0x560 [ 41.646554] [<000000005d05dcf1>] ? bpf_fd_pass+0x270/0x270 [ 41.652242] [<00000000e1427537>] ? __vfs_read+0x550/0x550 [ 41.657845] [<00000000b9288d5a>] ? trace_hardirqs_on+0xd/0x10 [ 41.663792] [<000000008b1a9b01>] ? selinux_file_permission+0x85/0x470 [ 41.670435] [<000000003a6f39d0>] ? security_file_permission+0x8f/0x1f0 [ 41.677167] [<000000008e9f6d78>] ? rw_verify_area+0xea/0x2b0 [ 41.683040] [<0000000002ecd86a>] vfs_write+0x185/0x520 [ 41.688382] [<00000000510bee0f>