[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 14.540074] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 18.501611] random: sshd: uninitialized urandom read (32 bytes read) [ 18.879997] random: sshd: uninitialized urandom read (32 bytes read) [ 19.808111] random: sshd: uninitialized urandom read (32 bytes read) [ 23.822661] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.10.22' (ECDSA) to the list of known hosts. [ 29.264805] random: sshd: uninitialized urandom read (32 bytes read) net.ipv6.conf.syz_tun.accept_dad = 0 net.ipv6.conf.syz_tun.router_solicitations = 0 [ 29.345331] IPVS: Creating netns size=2536 id=1 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 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 [ 29.464004] IPv6: ADDRCONF(NETDEV_UP): veth0_to_bridge: link is not ready [ 29.476001] 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 [ 29.518852] IPv6: ADDRCONF(NETDEV_UP): veth0_to_bond: link is not ready [ 29.530332] IPv6: ADDRCONF(NETDEV_UP): veth1_to_bond: link is not ready RTNETLINK answers: Operation not supported [ 29.572864] IPv6: ADDRCONF(NETDEV_UP): veth0_to_team: link is not ready [ 29.584513] IPv6: ADDRCONF(NETDEV_UP): veth1_to_team: link is not ready [ 29.597024] IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_bridge: link becomes ready [ 29.610144] 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" [ 30.094948] IPv6: ADDRCONF(NETDEV_UP): veth0: link is not ready [ 30.119547] IPv6: ADDRCONF(NETDEV_UP): veth1: link is not ready [ 30.125818] IPv6: ADDRCONF(NETDEV_CHANGE): veth1: link becomes ready [ 30.133035] ip (4106) used greatest stack depth: 23544 bytes left Cannot find device "team0" Cannot find device "team0" Cannot find device "team0" Cannot find device "team0" [ 30.139522] IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready executing program [ 30.337266] ================================================================== [ 30.344647] BUG: KASAN: use-after-free in tcp_connect+0x2633/0x2fa0 [ 30.351025] Read of size 4 at addr ffff8801da394a28 by task syz-executor787/4171 [ 30.358528] [ 30.360135] CPU: 0 PID: 4171 Comm: syz-executor787 Not tainted 4.9.107-g42a730a #48 [ 30.367900] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 30.377235] ffff8801d6c47930 ffffffff81eb42a9 ffffea000768e500 ffff8801da394a28 [ 30.385221] 0000000000000000 ffff8801da394a28 ffff8801b87b9c18 ffff8801d6c47968 [ 30.393196] ffffffff81567f09 ffff8801da394a28 0000000000000004 0000000000000000 [ 30.401185] Call Trace: [ 30.403749] [] dump_stack+0xc1/0x128 [ 30.409086] [] print_address_description+0x6c/0x234 [ 30.415723] [] kasan_report.cold.6+0x242/0x2fe [ 30.421932] [] ? tcp_connect+0x2633/0x2fa0 [ 30.427795] [] __asan_report_load4_noabort+0x14/0x20 [ 30.434521] [] tcp_connect+0x2633/0x2fa0 [ 30.440201] [] ? tcp_push_one+0xe0/0xe0 [ 30.445812] [] ? dst_release+0x70/0xb0 [ 30.451447] [] tcp_v4_connect+0x19f0/0x1c20 [ 30.457402] [] ? tcp_v4_inbound_md5_hash+0x3f0/0x3f0 [ 30.464129] [] ? selinux_socket_connect+0x167/0x4a0 [ 30.470765] [] __inet_stream_connect+0x6e0/0xbf0 [ 30.477158] [] ? mark_held_locks+0xc7/0x130 [ 30.483116] [] ? inet_bind+0x8b0/0x8b0 [ 30.488630] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 30.495453] [] ? lock_sock_nested+0x90/0x120 [ 30.501486] [] ? trace_hardirqs_on+0xd/0x10 [ 30.507438] [] ? __local_bh_enable_ip+0x6a/0xd0 [ 30.513739] [] inet_stream_connect+0x55/0xa0 [ 30.519777] [] SYSC_connect+0x1b8/0x300 [ 30.525383] [] ? vm_insert_mixed+0x200/0x200 [ 30.531416] [] ? SYSC_bind+0x280/0x280 [ 30.536926] [] ? do_futex+0x17c0/0x17c0 [ 30.542523] [] ? __do_page_fault+0x183/0xd50 [ 30.548567] [] SyS_connect+0x24/0x30 [ 30.553903] [] ? SyS_accept+0x30/0x30 [ 30.559325] [] do_syscall_64+0x1a6/0x490 [ 30.565008] [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 30.571900] [ 30.573508] Allocated by task 4171: [ 30.577107] save_stack_trace+0x16/0x20 [ 30.581049] save_stack+0x43/0xd0 [ 30.584482] kasan_kmalloc+0xc7/0xe0 [ 30.589061] kasan_slab_alloc+0x12/0x20 [ 30.593014] kmem_cache_alloc+0xbe/0x290 [ 30.597048] __alloc_skb+0xe6/0x600 [ 30.600654] sk_stream_alloc_skb+0xa3/0x5d0 [ 30.604944] tcp_sendmsg+0xe57/0x3040 [ 30.608715] inet_sendmsg+0x203/0x4d0 [ 30.612491] sock_sendmsg+0xcc/0x110 [ 30.616181] SYSC_sendto+0x21c/0x370 [ 30.619864] SyS_sendto+0x40/0x50 [ 30.623295] do_syscall_64+0x1a6/0x490 [ 30.627158] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 30.632242] [ 30.633837] Freed by task 4171: [ 30.637091] save_stack_trace+0x16/0x20 [ 30.641043] save_stack+0x43/0xd0 [ 30.644468] kasan_slab_free+0x72/0xc0 [ 30.648336] kmem_cache_free+0xbe/0x310 [ 30.652287] kfree_skbmem+0x7c/0x100 [ 30.655973] __kfree_skb+0x1d/0x20 [ 30.659487] tcp_connect+0xaaf/0x2fa0 [ 30.663269] tcp_v4_connect+0x19f0/0x1c20 [ 30.667388] __inet_stream_connect+0x6e0/0xbf0 [ 30.671941] inet_stream_connect+0x55/0xa0 [ 30.676158] SYSC_connect+0x1b8/0x300 [ 30.679929] SyS_connect+0x24/0x30 [ 30.683440] do_syscall_64+0x1a6/0x490 [ 30.687300] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 30.692368] [ 30.693975] The buggy address belongs to the object at ffff8801da394a00 [ 30.693975] which belongs to the cache skbuff_fclone_cache of size 456 [ 30.707296] The buggy address is located 40 bytes inside of [ 30.707296] 456-byte region [ffff8801da394a00, ffff8801da394bc8) [ 30.719053] The buggy address belongs to the page: [ 30.723957] page:ffffea000768e500 count:1 mapcount:0 mapping: (null) index:0x0 compound_mapcount: 0 [ 30.734146] flags: 0x8000000000004080(slab|head) [ 30.738875] page dumped because: kasan: bad access detected [ 30.744550] [ 30.746153] Memory state around the buggy address: [ 30.751052] ffff8801da394900: fb fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc [ 30.758383] ffff8801da394980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 30.765725] >ffff8801da394a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 30.773067] ^ [ 30.777704] ffff8801da394a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 30.785046] ffff8801da394b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 30.792373] ================================================================== [ 30.799700] Disabling lock debugging due to kernel taint [ 30.805890] Kernel panic - not syncing: panic_on_warn set ... [ 30.805890] [ 30.813247] CPU: 0 PID: 4171 Comm: syz-executor787 Tainted: G B 4.9.107-g42a730a #48 [ 30.822236] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 30.831561] ffff8801d6c47890 ffffffff81eb42a9 ffffffff843c642f 00000000ffffffff [ 30.839892] 0000000000000000 0000000000000000 ffff8801b87b9c18 ffff8801d6c47950 [ 30.847864] ffffffff81421e65 0000000041b58ab3 ffffffff843b9b50 ffffffff81421ca6 [ 30.855872] Call Trace: [ 30.858435] [] dump_stack+0xc1/0x128 [ 30.863768] [] panic+0x1bf/0x3bc [ 30.868761] [] ? add_taint.cold.6+0x16/0x16 [ 30.874706] [] ? ___preempt_schedule+0x16/0x18 [ 30.880907] [] kasan_end_report+0x47/0x4f [ 30.886675] [] kasan_report.cold.6+0x76/0x2fe [ 30.892792] [] ? tcp_connect+0x2633/0x2fa0 [ 30.898655] [] __asan_report_load4_noabort+0x14/0x20 [ 30.905393] [] tcp_connect+0x2633/0x2fa0 [ 30.911083] [] ? tcp_push_one+0xe0/0xe0 [ 30.916679] [] ? dst_release+0x70/0xb0 [ 30.922188] [] tcp_v4_connect+0x19f0/0x1c20 [ 30.928139] [] ? tcp_v4_inbound_md5_hash+0x3f0/0x3f0 [ 30.934872] [] ? selinux_socket_connect+0x167/0x4a0 [ 30.941515] [] __inet_stream_connect+0x6e0/0xbf0 [ 30.947900] [] ? mark_held_locks+0xc7/0x130 [ 30.953845] [] ? inet_bind+0x8b0/0x8b0 [ 30.959359] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 30.966182] [] ? lock_sock_nested+0x90/0x120 [ 30.972305] [] ? trace_hardirqs_on+0xd/0x10 [ 30.978263] [] ? __local_bh_enable_ip+0x6a/0xd0 [ 30.984558] [] inet_stream_connect+0x55/0xa0 [ 30.990600] [] SYSC_connect+0x1b8/0x300 [ 30.996211] [] ? vm_insert_mixed+0x200/0x200 [ 31.002245] [] ? SYSC_bind+0x280/0x280 [ 31.007757] [] ? do_futex+0x17c0/0x17c0 [ 31.013354] [] ? __do_page_fault+0x183/0xd50 [ 31.019385] [] SyS_connect+0x24/0x30 [ 31.024718] [] ? SyS_accept+0x30/0x30 [ 31.030153] [] do_syscall_64+0x1a6/0x490 [ 31.035858] [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 31.043117] Dumping ftrace buffer: [ 31.046628] (ftrace buffer empty) [ 31.050309] Kernel Offset: disabled [ 31.053917] Rebooting in 86400 seconds..