Starting mcstransd: [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [ 10.144931] random: sshd: uninitialized urandom read (32 bytes read) [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting file context maintaining daemon: restorecond[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 29.270931] random: sshd: uninitialized urandom read (32 bytes read) [ 29.280194] random: crng init done Warning: Permanently added '10.128.10.48' (ECDSA) to the list of known hosts. 2019/06/27 07:31:27 parsed 1 programs 2019/06/27 07:31:30 executed programs: 0 [ 65.256627] audit: type=1400 audit(1561620690.851:5): avc: denied { associate } for pid=2083 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 [ 65.296070] [ 65.297761] =============================== [ 65.302087] [ INFO: suspicious RCU usage. ] [ 65.306432] 4.9.183+ #4 Not tainted [ 65.310054] ------------------------------- [ 65.314396] ./include/linux/inetdevice.h:205 suspicious rcu_dereference_check() usage! [ 65.322605] [ 65.322605] other info that might help us debug this: [ 65.322605] [ 65.330860] [ 65.330860] rcu_scheduler_active = 2, debug_locks = 0 [ 65.337661] 4 locks held by syz-executor.0/2231: [ 65.342432] #0: (rcu_read_lock_bh){......}, at: [<00000000ccdbd4eb>] ip_finish_output2+0x20b/0x1280 [ 65.352475] #1: (rcu_read_lock_bh){......}, at: [<000000006ddc5fc4>] __dev_queue_xmit+0x1d4/0x1bd0 [ 65.362309] #2: (_xmit_TUNNEL6#2){+.....}, at: [<00000000187718e2>] __dev_queue_xmit+0x1116/0x1bd0 [ 65.372229] #3: (slock-AF_INET){+.-...}, at: [<000000005d989347>] __icmp_send+0x48b/0x1420 [ 65.381505] [ 65.381505] stack backtrace: [ 65.386156] CPU: 0 PID: 2231 Comm: syz-executor.0 Not tainted 4.9.183+ #4 [ 65.393077] ffff8801cb5fedd8 ffffffff81b580a1 ffff8801ce403140 0000000000000000 [ 65.401224] 0000000000000002 00000000000000cd ffff8801cb43af80 ffff8801cb5fee08 [ 65.409298] ffffffff81404fb9 ffff8801ce403198 ffff8801cb5fef28 ffff8801d9d2d500 [ 65.417483] Call Trace: [ 65.420059] [<000000007032fe5a>] dump_stack+0xc1/0x120 [ 65.425419] [<00000000ecc78a3e>] lockdep_rcu_suspicious.cold+0x10a/0x149 [ 65.432352] [<0000000092ab2c65>] fib_compute_spec_dst+0x6c4/0xcc0 [ 65.438772] [<00000000bcecd947>] ? fib_unmerge+0x4c0/0x4c0 [ 65.444484] [<00000000b4a2cb4e>] ? trace_hardirqs_on+0x10/0x10 [ 65.451012] [<000000002c54e669>] ? __lock_acquire+0x5e5/0x4350 [ 65.457060] [<00000000ea84113e>] __ip_options_echo+0x4be/0x13e0 [ 65.463356] [<0000000059bf97da>] __icmp_send+0x648/0x1420 [ 65.468982] [<00000000cc64ca55>] ? __icmp_send+0xc07/0x1420 [ 65.474903] [<000000002c54e669>] ? __lock_acquire+0x5e5/0x4350 [ 65.480959] [<00000000077fc4d8>] ? icmpv4_xrlim_allow.isra.0+0x2d0/0x2d0 [ 65.487893] [<00000000b4a2cb4e>] ? trace_hardirqs_on+0x10/0x10 [ 65.493957] [<000000009e098e2c>] ? debug_lockdep_rcu_enabled+0x71/0xa0 [ 65.501436] [<000000009c34d84b>] ? __ip_options_compile+0x668/0x13c0 [ 65.508036] [<0000000079356092>] ? check_preemption_disabled+0x3c/0x200 [ 65.514875] [<00000000d13fa813>] ? ipv4_link_failure+0x410/0x850 [ 65.534487] [<00000000b145774d>] ipv4_link_failure+0x460/0x850 [ 65.540747] [<000000003b3b9ca8>] ? ipv4_link_failure+0x32b/0x850 [ 65.547114] [<000000002a09c93f>] ? rt_dst_alloc+0x450/0x450 [ 65.553489] [<000000002a09c93f>] ? rt_dst_alloc+0x450/0x450 [ 65.559796] [<00000000898f6e02>] vti6_tnl_xmit+0xb08/0x17f0 [ 65.565595] [<00000000b3db8930>] ? vti6_dellink+0x270/0x270 [ 65.571531] [<00000000ef8c27d6>] dev_hard_start_xmit+0x195/0x8b0 [ 65.577894] [<00000000b15e9d53>] __dev_queue_xmit+0x11a3/0x1bd0 [ 65.584155] [<000000006ddc5fc4>] ? __dev_queue_xmit+0x1d4/0x1bd0 [ 65.590442] [<00000000c3d320d5>] ? __local_bh_enable_ip+0x6a/0xe0 [ 65.598051] [<0000000069147718>] ? netdev_pick_tx+0x300/0x300 [ 65.604412] [<00000000d574962d>] ? __neigh_create+0x96e/0x1b30 [ 65.610561] [<00000000a027ea9b>] dev_queue_xmit+0x18/0x20 [ 65.616218] [<00000000b4873a12>] neigh_direct_output+0x16/0x20 [ 65.622366] [<00000000442d4da8>] ip_finish_output2+0x6a2/0x1280 [ 65.628494] [<00000000ccdbd4eb>] ? ip_finish_output2+0x20b/0x1280 [ 65.634976] [<000000002fd778d6>] ? rcu_read_lock_held+0x9e/0xc0 [ 65.641102] [<00000000489df0ac>] ? nf_iterate+0x19e/0x310 [ 65.646722] [<00000000d2bd0450>] ? ip_send_check+0xb0/0xb0 [ 65.652417] [<000000009e098e2c>] ? debug_lockdep_rcu_enabled+0x71/0xa0 [ 65.659170] [<00000000a0616f0e>] ? nf_hook_slow+0x12f/0x1f0 [ 65.665022] [<00000000d1411312>] ip_finish_output+0x3c4/0xce0 [ 65.671113] [<0000000009b1faf0>] ip_output+0x1ec/0x5b0 [ 65.676633] [<00000000fcbc3405>] ? ip_output+0x287/0x5b0 [ 65.682346] [<0000000032b82fa6>] ? ip_mc_output+0xcb0/0xcb0 [ 65.688142] [<00000000467bb04b>] ? nf_hook_slow+0x62/0x1f0 [ 65.694047] [<00000000aea69fdc>] ? ip_fragment.constprop.0+0x210/0x210 [ 65.700802] [<0000000079356092>] ? check_preemption_disabled+0x3c/0x200 [ 65.707629] [<0000000014cb8f11>] ? raw_sendmsg+0x1929/0x23e0 [ 65.713507] [<00000000a8261868>] raw_sendmsg+0x1c5c/0x23e0 [ 65.719219] [<000000004a903803>] ? raw_sendmsg+0x1851/0x23e0 [ 65.725107] [<00000000261844af>] ? avc_has_perm+0x164/0x3a0 [ 65.731566] [<00000000e4f5bd10>] ? compat_raw_setsockopt+0xd0/0xd0 [ 65.737978] [<000000002c54e669>] ? __lock_acquire+0x5e5/0x4350 [ 65.744037] [<000000009e098e2c>] ? debug_lockdep_rcu_enabled+0x71/0xa0 [ 65.750775] [<0000000079356092>] ? check_preemption_disabled+0x3c/0x200 [ 65.757722] [<0000000057de5faf>] ? trace_hardirqs_on_caller+0x4f2/0x5a0 [ 65.764816] [<0000000098f341db>] ? ip4_datagram_release_cb+0x970/0x970 [ 65.772110] [<00000000f006e9d1>] ? selinux_msg_queue_alloc_security+0x2e0/0x2e0 [ 65.779648] [<000000009e098e2c>] ? debug_lockdep_rcu_enabled+0x71/0xa0 [ 65.786389] [<0000000079356092>] ? check_preemption_disabled+0x3c/0x200 [ 65.793252] [<0000000079356092>] ? check_preemption_disabled+0x3c/0x200 [ 65.800179] [<0000000079356092>] ? check_preemption_disabled+0x3c/0x200 [ 65.807023] [<00000000868a2bd9>] ? inet_sendmsg+0x143/0x4d0 [ 65.812996] [<000000006ecd9e86>] inet_sendmsg+0x202/0x4d0 [ 65.818613] [<0000000095359e21>] ? inet_sendmsg+0x76/0x4d0 [ 65.824323] [<00000000c72bcb94>] ? inet_recvmsg+0x4d0/0x4d0 [ 65.830108] [<0000000086d9c3a0>] sock_sendmsg+0xbe/0x110 [ 65.835699] [<00000000391b0a7c>] sock_write_iter+0x235/0x3d0 [ 65.841635] [<000000006468b062>] ? sock_sendmsg+0x110/0x110 [ 65.847617] [<00000000062c5921>] ? iov_iter_init+0xaf/0x1d0 [ 65.853620] [<000000002d3a178d>] __vfs_write+0x3c1/0x560 [ 65.859204] [<000000004ac52c0b>] ? bpf_fd_pass+0x270/0x270 [ 65.864918] [<00000000fb3b01a2>] ? __vfs_read+0x550/0x550 [ 65.870536] [<00000000de689616>] ? trace_hardirqs_on+0xd/0x10 [ 65.876739] [<00000000cb9a54b9>] ? selinux_file_permission+0x85/0x470 [ 65.883933] [<00000000b3fe2c71>] ? security_file_permission+0x8f/0x1f0 [ 65.891091] [<00000000dd603714>] ? rw_verify_area+0xea/0x2b0 [ 65.897700] [<00000000b03f2fad>] vfs_write+0x185/0x520 [ 65.903435] [<000000007a873696>] SyS_write+0x121/0x270 [ 65.9