[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 12.167883] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 20.113558] random: sshd: uninitialized urandom read (32 bytes read) [ 20.336050] random: sshd: uninitialized urandom read (32 bytes read) [ 21.129270] random: sshd: uninitialized urandom read (32 bytes read) [ 31.464101] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.0.42' (ECDSA) to the list of known hosts. [ 36.863242] random: sshd: uninitialized urandom read (32 bytes read) RTNETLINK answers: Operation not supported RTNETLINK answers: Operation not supported RTNETLINK answers: Operation not supported RTNETLINK answers: Operation not supported RTNETLINK answers: Operation not supported [ 36.944626] IPVS: Creating netns size=2536 id=1 Error: argument "bridge0" is wrong: Device does not exist Error: argument "bridge0" is wrong: Device does not exist Error: argument "bond0" is wrong: Device does not exist Error: argument "bond0" is wrong: Device does not exist [ 37.023358] IPv6: ADDRCONF(NETDEV_UP): veth0_to_bridge: link is not ready [ 37.034717] IPv6: ADDRCONF(NETDEV_UP): veth1_to_bridge: link is not ready Error: argument "team0" is wrong: Device does not exist Error: argument "team0" is wrong: Device does not exist [ 37.074696] IPv6: ADDRCONF(NETDEV_UP): veth0_to_bond: link is not ready [ 37.086029] IPv6: ADDRCONF(NETDEV_UP): veth1_to_bond: link is not ready RTNETLINK answers: Operation not supported [ 37.125837] IPv6: ADDRCONF(NETDEV_UP): veth0_to_team: link is not ready [ 37.136681] IPv6: ADDRCONF(NETDEV_UP): veth1_to_team: link is not ready [ 37.147987] IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_bridge: link becomes ready [ 37.168041] IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_bridge: link becomes ready 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" Cannot find device "bond0" Cannot find device "bond0" Cannot find device "bond0" Cannot find device "bond0" Cannot find device "team0" Cannot find device "team0" Cannot find device "team0" Cannot find device "team0" [ 37.603717] IPv6: ADDRCONF(NETDEV_UP): veth0: link is not ready [ 37.626342] IPv6: ADDRCONF(NETDEV_UP): veth1: link is not ready [ 37.632736] IPv6: ADDRCONF(NETDEV_CHANGE): veth1: link becomes ready [ 37.639417] IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready executing program [ 37.781246] ================================================================== [ 37.788627] BUG: KASAN: use-after-free in __dev_queue_xmit+0x18fc/0x2080 [ 37.795437] Read of size 2 at addr ffff8801be0dd4c2 by task syz-executor852/3805 [ 37.802935] [ 37.804537] CPU: 1 PID: 3805 Comm: syz-executor852 Not tainted 4.9.101-gaef17a5 #29 [ 37.812325] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 37.821657] ffff8801d96e7500 ffffffff81eb1009 ffffea0006f83700 ffff8801be0dd4c2 [ 37.829632] 0000000000000000 ffff8801be0dd4c2 ffff8801d769b0d0 ffff8801d96e7538 [ 37.837606] ffffffff8156541b ffff8801be0dd4c2 0000000000000002 0000000000000000 [ 37.845586] Call Trace: [ 37.848144] [] dump_stack+0xc1/0x128 [ 37.853484] [] print_address_description+0x6c/0x234 [ 37.860119] [] kasan_report.cold.6+0x242/0x2fe [ 37.866320] [] ? __dev_queue_xmit+0x18fc/0x2080 [ 37.872609] [] __asan_report_load2_noabort+0x14/0x20 [ 37.879328] [] __dev_queue_xmit+0x18fc/0x2080 [ 37.885443] [] ? __dev_queue_xmit+0x1e2/0x2080 [ 37.891643] [] ? netdev_pick_tx+0x2c0/0x2c0 [ 37.897586] [] ? __cap_capable+0x168/0x1c0 [ 37.903448] [] ? selinux_capable+0x36/0x40 [ 37.909301] [] ? security_capable+0x94/0xc0 [ 37.915240] [] dev_queue_xmit+0x17/0x20 [ 37.920835] [] packet_sendmsg+0x1eff/0x4470 [ 37.926786] [] ? debug_check_no_locks_freed+0x210/0x210 [ 37.933769] [] ? packet_cached_dev_get+0x1f0/0x1f0 [ 37.940316] [] ? sock_has_perm+0x292/0x3e0 [ 37.946169] [] ? sock_has_perm+0x9f/0x3e0 [ 37.951937] [] ? selinux_file_send_sigiotask+0x310/0x310 [ 37.959008] [] ? selinux_socket_sendmsg+0x3f/0x50 [ 37.965470] [] ? security_socket_sendmsg+0x8f/0xc0 [ 37.972019] [] ? packet_cached_dev_get+0x1f0/0x1f0 [ 37.978584] [] sock_sendmsg+0xcc/0x110 [ 37.984090] [] ___sys_sendmsg+0x47a/0x840 [ 37.989857] [] ? get_page_from_freelist+0xcb6/0x1a00 [ 37.996579] [] ? copy_msghdr_from_user+0x560/0x560 [ 38.003128] [] ? debug_check_no_locks_freed+0x210/0x210 [ 38.010119] [] ? __activate_page+0x790/0x790 [ 38.016151] [] ? _raw_spin_unlock_irqrestore+0x5a/0x70 [ 38.023054] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 38.029864] [] __sys_sendmmsg+0x161/0x3d0 [ 38.035630] [] ? SyS_sendmsg+0x50/0x50 [ 38.041140] [] ? handle_mm_fault+0x6a4/0x28e0 [ 38.047255] [] ? packet_bind+0x13f/0x190 [ 38.052935] [] ? vm_insert_mixed+0x200/0x200 [ 38.058963] [] ? up_read+0x1a/0x40 [ 38.064123] [] ? __do_page_fault+0x183/0xd50 [ 38.070149] [] SyS_sendmmsg+0x35/0x60 [ 38.075571] [] ? __sys_sendmmsg+0x3d0/0x3d0 [ 38.081512] [] do_syscall_64+0x1a6/0x490 [ 38.087194] [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 38.094085] [ 38.095684] Allocated by task 3805: [ 38.099289] save_stack_trace+0x16/0x20 [ 38.103233] save_stack+0x43/0xd0 [ 38.106655] kasan_kmalloc+0xc7/0xe0 [ 38.110337] kasan_slab_alloc+0x12/0x20 [ 38.114280] __kmalloc_track_caller+0xdc/0x2b0 [ 38.118834] __kmalloc_reserve.isra.37+0x33/0xc0 [ 38.123563] __alloc_skb+0x11a/0x600 [ 38.127247] alloc_skb_with_frags+0xaf/0x520 [ 38.131626] sock_alloc_send_pskb+0x5a9/0x750 [ 38.136096] packet_sendmsg+0x1581/0x4470 [ 38.140214] sock_sendmsg+0xcc/0x110 [ 38.143905] ___sys_sendmsg+0x47a/0x840 [ 38.147849] __sys_sendmmsg+0x161/0x3d0 [ 38.151800] SyS_sendmmsg+0x35/0x60 [ 38.155399] do_syscall_64+0x1a6/0x490 [ 38.159372] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 38.164441] [ 38.166038] Freed by task 3805: [ 38.169286] save_stack_trace+0x16/0x20 [ 38.173233] save_stack+0x43/0xd0 [ 38.176656] kasan_slab_free+0x72/0xc0 [ 38.180514] kfree+0xfb/0x310 [ 38.183589] skb_free_head+0x8b/0xb0 [ 38.187272] skb_release_data+0x329/0x400 [ 38.191387] skb_release_all+0x4a/0x60 [ 38.195245] __kfree_skb+0x15/0x20 [ 38.198752] kfree_skb+0xcc/0x340 [ 38.202174] __skb_complete_tx_timestamp+0x2ba/0x3a0 [ 38.207248] __skb_tstamp_tx+0x19a/0x4b0 [ 38.211276] __dev_queue_xmit+0x130f/0x2080 [ 38.215563] dev_queue_xmit+0x17/0x20 [ 38.219334] packet_sendmsg+0x1eff/0x4470 [ 38.223449] sock_sendmsg+0xcc/0x110 [ 38.227132] ___sys_sendmsg+0x47a/0x840 [ 38.231075] __sys_sendmmsg+0x161/0x3d0 [ 38.235017] SyS_sendmmsg+0x35/0x60 [ 38.238611] do_syscall_64+0x1a6/0x490 [ 38.242469] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 38.247537] [ 38.249135] The buggy address belongs to the object at ffff8801be0dd400 [ 38.249135] which belongs to the cache kmalloc-512 of size 512 [ 38.261759] The buggy address is located 194 bytes inside of [ 38.261759] 512-byte region [ffff8801be0dd400, ffff8801be0dd600) [ 38.273608] The buggy address belongs to the page: [ 38.278507] page:ffffea0006f83700 count:1 mapcount:0 mapping: (null) index:0x0 compound_mapcount: 0 [ 38.288672] flags: 0x8000000000004080(slab|head) [ 38.293392] page dumped because: kasan: bad access detected [ 38.299068] [ 38.300667] Memory state around the buggy address: [ 38.305569] ffff8801be0dd380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 38.312894] ffff8801be0dd400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 38.320221] >ffff8801be0dd480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 38.327549] ^ [ 38.332967] ffff8801be0dd500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 38.340304] ffff8801be0dd580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 38.347631] ================================================================== [ 38.354957] Disabling lock debugging due to kernel taint [ 38.360418] Kernel panic - not syncing: panic_on_warn set ... [ 38.360418] [ 38.367751] CPU: 1 PID: 3805 Comm: syz-executor852 Tainted: G B 4.9.101-gaef17a5 #29 [ 38.376731] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 38.386075] ffff8801d96e7460 ffffffff81eb1009 ffffffff843c50e5 00000000ffffffff [ 38.394094] 0000000000000000 0000000000000001 ffff8801d769b0d0 ffff8801d96e7520 [ 38.402085] ffffffff8141f925 0000000041b58ab3 ffffffff843b87e8 ffffffff8141f766 [ 38.410071] Call Trace: [ 38.412631] [] dump_stack+0xc1/0x128 [ 38.417966] [] panic+0x1bf/0x3bc [ 38.422951] [] ? add_taint.cold.6+0x16/0x16 [ 38.429251] [] kasan_end_report+0x47/0x4f [ 38.435019] [] kasan_report.cold.6+0x76/0x2fe [ 38.441136] [] ? __dev_queue_xmit+0x18fc/0x2080 [ 38.447425] [] __asan_report_load2_noabort+0x14/0x20 [ 38.454146] [] __dev_queue_xmit+0x18fc/0x2080 [ 38.460268] [] ? __dev_queue_xmit+0x1e2/0x2080 [ 38.466468] [] ? netdev_pick_tx+0x2c0/0x2c0 [ 38.472409] [] ? __cap_capable+0x168/0x1c0 [ 38.478268] [] ? selinux_capable+0x36/0x40 [ 38.484209] [] ? security_capable+0x94/0xc0 [ 38.490149] [] dev_queue_xmit+0x17/0x20 [ 38.495747] [] packet_sendmsg+0x1eff/0x4470 [ 38.501689] [] ? debug_check_no_locks_freed+0x210/0x210 [ 38.508672] [] ? packet_cached_dev_get+0x1f0/0x1f0 [ 38.515220] [] ? sock_has_perm+0x292/0x3e0 [ 38.521072] [] ? sock_has_perm+0x9f/0x3e0 [ 38.526837] [] ? selinux_file_send_sigiotask+0x310/0x310 [ 38.533906] [] ? selinux_socket_sendmsg+0x3f/0x50 [ 38.540368] [] ? security_socket_sendmsg+0x8f/0xc0 [ 38.546918] [] ? packet_cached_dev_get+0x1f0/0x1f0 [ 38.553470] [] sock_sendmsg+0xcc/0x110 [ 38.558977] [] ___sys_sendmsg+0x47a/0x840 [ 38.564752] [] ? get_page_from_freelist+0xcb6/0x1a00 [ 38.571476] [] ? copy_msghdr_from_user+0x560/0x560 [ 38.578033] [] ? debug_check_no_locks_freed+0x210/0x210 [ 38.585013] [] ? __activate_page+0x790/0x790 [ 38.591043] [] ? _raw_spin_unlock_irqrestore+0x5a/0x70 [ 38.597937] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 38.604746] [] __sys_sendmmsg+0x161/0x3d0 [ 38.610515] [] ? SyS_sendmsg+0x50/0x50 [ 38.616023] [] ? handle_mm_fault+0x6a4/0x28e0 [ 38.622149] [] ? packet_bind+0x13f/0x190 [ 38.627832] [] ? vm_insert_mixed+0x200/0x200 [ 38.633869] [] ? up_read+0x1a/0x40 [ 38.639034] [] ? __do_page_fault+0x183/0xd50 [ 38.645066] [] SyS_sendmmsg+0x35/0x60 [ 38.650486] [] ? __sys_sendmmsg+0x3d0/0x3d0 [ 38.656429] [] do_syscall_64+0x1a6/0x490 [ 38.662111] [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 38.669419] Dumping ftrace buffer: [ 38.672928] (ftrace buffer empty) [ 38.676610] Kernel Offset: disabled [ 38.680214] Rebooting in 86400 seconds..