[....] Starting periodic command scheduler: cron[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. [....] Starting file context maintaining daemon: restorecond[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 18.776898] random: sshd: uninitialized urandom read (32 bytes read, 32 bits of entropy available) [?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 19.992494] random: sshd: uninitialized urandom read (32 bytes read, 35 bits of entropy available) [ 20.177432] random: sshd: uninitialized urandom read (32 bytes read, 35 bits of entropy available) [ 21.042315] random: nonblocking pool is initialized Warning: Permanently added '10.128.0.50' (ECDSA) to the list of known hosts. net.ipv6.conf.syz0.accept_dad = 0 net.ipv6.conf.syz0.router_solicitations = 0 RTNETLINK answers: Operation not supported RTNETLINK answers: Operation not supported RTNETLINK answers: Operation not supported RTNETLINK answers: Operation not supported Cannot find device "bridge0" Cannot find device "bridge0" Cannot find device "bridge0" Cannot find device "bridge0" Cannot find device "vcan0" Cannot find device "vcan0" Cannot find device "vcan0" Cannot find device "vcan0" RTNETLINK answers: Operation not supported Cannot find device "gre0" Cannot find device "gre0" Cannot find device "gre0" Cannot find device "gre0" Cannot find device "gretap0" Cannot find device "gretap0" Cannot find device "gretap0" Cannot find device "gretap0" Cannot find device "ip_vti0" Cannot find device "ip_vti0" Cannot find device "ip_vti0" Cannot find device "ip_vti0" Cannot find device "ip6_vti0" Cannot find device "ip6_vti0" Cannot find device "ip6_vti0" Cannot find device "ip6_vti0" Cannot find device "ip6tnl0" Cannot find device "ip6tnl0" Cannot find device "ip6tnl0" Cannot find device "ip6tnl0" Cannot find device "ip6gre0" Cannot find device "ip6gre0" Cannot find device "ip6gre0" Cannot find device "ip6gre0" Cannot find device "ip6gretap0" Cannot find device "ip6gretap0" Cannot find device "ip6gretap0" Cannot find device "ip6gretap0" Cannot find device "erspan0" Cannot find device "erspan0" Cannot find device "erspan0" Cannot find device "erspan0" executing program [ 27.594533] ------------[ cut here ]------------ [ 27.599329] WARNING: CPU: 1 PID: 3689 at net/core/dev.c:2449 skb_warn_bad_offload+0x2af/0x390() [ 27.608152] syz0: caps=(0x00000080000048c1, 0x0000000000000000) len=90 data_len=0 gso_size=574 gso_type=5 ip_summed=0 [ 27.618874] Kernel panic - not syncing: panic_on_warn set ... [ 27.618874] [ 27.626211] CPU: 1 PID: 3689 Comm: syzkaller253997 Not tainted 4.4.115-g55a366596 #14 [ 27.634162] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 27.643486] 0000000000000000 5206f6690a7f9fde ffff8801c982f450 ffffffff81d03d8d [ 27.651450] ffffffff83843a60 ffff8801c982f528 ffffffff83caac60 0000000000000009 [ 27.659419] 0000000000000991 ffff8801c982f518 ffffffff8141acba 0000000041b58ab3 [ 27.667390] Call Trace: [ 27.669946] [] dump_stack+0xc1/0x124 [ 27.675277] [] panic+0x1aa/0x388 [ 27.680262] [] ? percpu_up_read.constprop.45+0xe1/0xe1 [ 27.687155] [] ? warn_slowpath_common+0x10a/0x140 [ 27.693612] [] warn_slowpath_common+0x125/0x140 [ 27.699905] [] ? skb_warn_bad_offload+0x2af/0x390 [ 27.706371] [] warn_slowpath_fmt+0xc1/0x110 [ 27.712310] [] ? warn_slowpath_common+0x140/0x140 [ 27.718768] [] ? ___ratelimit+0x212/0x3e0 [ 27.724534] [] ? _raw_spin_unlock_irqrestore+0x45/0x70 [ 27.731427] [] ? ___ratelimit+0x53/0x3e0 [ 27.737107] [] skb_warn_bad_offload+0x2af/0x390 [ 27.743393] [] __skb_gso_segment+0x3b3/0x4a0 [ 27.749421] [] validate_xmit_skb.isra.101.part.102+0x44e/0x970 [ 27.757010] [] validate_xmit_skb_list+0xae/0x110 [ 27.763383] [] sch_direct_xmit+0x34f/0x760 [ 27.769233] [] ? dev_deactivate_queue.constprop.34+0x150/0x150 [ 27.776823] [] ? __dev_queue_xmit+0x1d5/0x1cc0 [ 27.783027] [] __dev_queue_xmit+0x148e/0x1cc0 [ 27.789138] [] ? __dev_queue_xmit+0x1d5/0x1cc0 [ 27.795354] [] ? netdev_pick_tx+0x310/0x310 [ 27.801292] [] ? tun_select_queue+0x1a1/0x380 [ 27.807403] [] ? tun_select_queue+0x1c8/0x380 [ 27.813514] [] ? tun_chr_ioctl+0x40/0x40 [ 27.819198] [] ? tun_chr_ioctl+0x40/0x40 [ 27.824875] [] dev_queue_xmit+0x17/0x20 [ 27.830467] [] packet_sendmsg+0x29b2/0x47e0 [ 27.836408] [] ? avc_has_perm_noaudit+0x460/0x460 [ 27.842868] [] ? packet_cached_dev_get+0x200/0x200 [ 27.849416] [] ? selinux_file_send_sigiotask+0x310/0x310 [ 27.856483] [] ? __might_fault+0xe4/0x1d0 [ 27.862246] [] ? selinux_socket_sendmsg+0x3f/0x50 [ 27.868711] [] ? security_socket_sendmsg+0x89/0xb0 [ 27.875256] [] ? packet_cached_dev_get+0x200/0x200 [ 27.881804] [] sock_sendmsg+0xca/0x110 [ 27.887307] [] SYSC_sendto+0x2c8/0x340 [ 27.892815] [] ? SYSC_connect+0x310/0x310 [ 27.898584] [] ? sock_has_perm+0x29f/0x400 [ 27.904443] [] ? selinux_file_send_sigiotask+0x310/0x310 [ 27.911519] [] ? selinux_netlbl_socket_setsockopt+0x117/0x320 [ 27.919030] [] ? selinux_netlbl_sock_rcv_skb+0x400/0x400 [ 27.926107] [] ? SyS_setsockopt+0x17f/0x250 [ 27.932053] [] ? SyS_recv+0x40/0x40 [ 27.937301] [] ? up_read+0x1a/0x40 [ 27.942465] [] ? __do_page_fault+0x149/0xa00 [ 27.948493] [] ? security_file_ioctl+0x89/0xb0 [ 27.954694] [] SyS_sendto+0x40/0x50 [ 27.959939] [] entry_SYSCALL_64_fastpath+0x1c/0x98 [ 27.966982] Dumping ftrace buffer: [ 27.970502] (ftrace buffer empty) [ 27.974184] Kernel Offset: disabled [ 27.977792] Rebooting in 86400 seconds..