[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. [....] Starting periodic command scheduler: cron[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. Starting mcstransd: [ 12.235488] random: crng init done [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. [....] Starting file context maintaining daemon: restorecond[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.10.3' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 19.436153] ------------[ cut here ]------------ [ 19.440986] WARNING: CPU: 1 PID: 2219 at net/core/skbuff.c:4353 skb_try_coalesce+0xeb1/0x1270 [ 19.449693] Kernel panic - not syncing: panic_on_warn set ... [ 19.449693] [ 19.457059] CPU: 1 PID: 2219 Comm: syz-executor358 Not tainted 4.9.125+ #88 [ 19.464138] ffff8801c74473e0 ffffffff81af0ae9 ffffffff82838ba0 00000000ffffffff [ 19.472136] 0000000000000000 0000000000000001 0000000000001101 ffff8801c74474a0 [ 19.480161] ffffffff813df095 0000000041b58ab3 ffffffff82c28773 ffffffff813deed6 [ 19.488152] Call Trace: [ 19.490717] [] dump_stack+0xc1/0x128 [ 19.496064] [] panic+0x1bf/0x39f [ 19.501064] [] ? add_taint.cold.6+0x16/0x16 [ 19.507018] [] ? minmax_running_min+0x19a/0x580 [ 19.513316] [] ? __warn.cold.9+0xa6/0x17f [ 19.519098] [] ? skb_try_coalesce+0xeb1/0x1270 [ 19.525314] [] __warn.cold.9+0xc1/0x17f [ 19.530920] [] ? bictcp_cong_avoid+0xcd/0xdf0 [ 19.537049] [] warn_slowpath_null+0x2c/0x40 [ 19.543006] [] skb_try_coalesce+0xeb1/0x1270 [ 19.549047] [] tcp_try_coalesce+0x159/0x490 [ 19.555007] [] ? tcp_prune_ofo_queue.part.19+0x460/0x460 [ 19.562095] [] ? tcp_try_rmem_schedule+0x13a/0x1010 [ 19.568745] [] tcp_queue_rcv+0x127/0x590 [ 19.574437] [] tcp_data_queue+0x96d/0x38a0 [ 19.580311] [] ? trace_hardirqs_on+0x10/0x10 [ 19.586355] [] ? tcp_fin+0x7c0/0x7c0 [ 19.591703] [] ? tcp_xmit_recovery.part.25+0x120/0x120 [ 19.598611] [] ? debug_lockdep_rcu_enabled+0x77/0x90 [ 19.605357] [] tcp_rcv_established+0x53d/0x1ff0 [ 19.611657] [] ? check_preemption_disabled+0x3b/0x170 [ 19.618492] [] ? rt6_check+0x114/0x250 [ 19.624014] [] ? tcp_data_queue+0x38a0/0x38a0 [ 19.630148] [] ? rt6_check+0x169/0x250 [ 19.635945] [] ? rt6_check_expired+0x120/0x120 [ 19.642162] [] tcp_v6_do_rcv+0xcd1/0x10e0 [ 19.647947] [] __release_sock+0x13a/0x390 [ 19.653748] [] __sk_flush_backlog+0x27/0x40 [ 19.659697] [] ? ipv6_frag_exit+0x40/0x40 [ 19.665476] [] tcp_sendmsg+0x245e/0x2fd0 [ 19.671167] [] ? tcp_sendpage+0x1910/0x1910 [ 19.677120] [] ? sock_has_perm+0x293/0x3e0 [ 19.682981] [] ? sock_has_perm+0x9f/0x3e0 [ 19.688760] [] ? selinux_msg_queue_alloc_security+0x2e0/0x2e0 [ 19.696274] [] ? debug_lockdep_rcu_enabled+0x77/0x90 [ 19.703020] [] ? check_preemption_disabled+0x3b/0x170 [ 19.709844] [] ? inet_sendmsg+0x143/0x4d0 [ 19.715624] [] inet_sendmsg+0x203/0x4d0 [ 19.721258] [] ? inet_sendmsg+0x73/0x4d0 [ 19.726947] [] ? inet_recvmsg+0x4c0/0x4c0 [ 19.732732] [] sock_sendmsg+0xbb/0x110 [ 19.738247] [] SyS_sendto+0x220/0x370 [ 19.743676] [] ? SyS_getpeername+0x2d0/0x2d0 [ 19.749737] [] ? _raw_spin_unlock+0x2c/0x50 [ 19.755686] [] ? handle_mm_fault+0x54b/0x2350 [ 19.761809] [] ? vm_insert_page+0x6f0/0x6f0 [ 19.767760] [] ? SyS_bind+0x18a/0x280 [ 19.773188] [] ? debug_lockdep_rcu_enabled+0x77/0x90 [ 19.779918] [] ? __do_page_fault+0x431/0xa60 [ 19.785958] [] ? up_read+0x1a/0x40 [ 19.791145] [] ? __do_page_fault+0x554/0xa60 [ 19.797178] [] ? do_syscall_64+0x48/0x480 [ 19.802961] [] ? SyS_getpeername+0x2d0/0x2d0 [ 19.808999] [] do_syscall_64+0x19f/0x480 [ 19.814689] [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 19.821904] Dumping ftrace buffer: [ 19.825485] (ftrace buffer empty) [ 19.829177] Kernel Offset: disabled [ 19.832786] Rebooting in 86400 seconds..