[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 13.556688] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 19.061470] random: sshd: uninitialized urandom read (32 bytes read) [ 19.439963] random: sshd: uninitialized urandom read (32 bytes read) [ 20.250748] random: sshd: uninitialized urandom read (32 bytes read) [ 20.386793] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.10.0' (ECDSA) to the list of known hosts. [ 25.781305] 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 [ 25.867074] 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 [ 25.946912] IPv6: ADDRCONF(NETDEV_UP): veth0_to_bridge: link is not ready [ 25.958450] 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 [ 25.999747] IPv6: ADDRCONF(NETDEV_UP): veth0_to_bond: link is not ready [ 26.010842] IPv6: ADDRCONF(NETDEV_UP): veth1_to_bond: link is not ready [ 26.051632] IPv6: ADDRCONF(NETDEV_UP): veth0_to_team: link is not ready [ 26.062964] IPv6: ADDRCONF(NETDEV_UP): veth1_to_team: link is not ready [ 26.074639] IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_bridge: link becomes ready RTNETLINK answers: Operation not supported [ 26.095493] 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" [ 26.566752] IPv6: ADDRCONF(NETDEV_UP): veth0: link is not ready [ 26.589878] IPv6: ADDRCONF(NETDEV_UP): veth1: link is not ready [ 26.596095] IPv6: ADDRCONF(NETDEV_CHANGE): veth1: link becomes ready [ 26.602797] IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready executing program [ 26.796662] ================================================================== [ 26.804056] BUG: KASAN: use-after-free in tcp_connect+0x2633/0x2fa0 [ 26.810434] Read of size 4 at addr ffff8801ba8f56a8 by task syz-executor383/4156 [ 26.817946] [ 26.819661] CPU: 0 PID: 4156 Comm: syz-executor383 Not tainted 4.9.103-g70c65e4 #37 [ 26.827422] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 26.836747] ffff8801cb767930 ffffffff81eb3469 ffffea0006ea3d00 ffff8801ba8f56a8 [ 26.844731] 0000000000000000 ffff8801ba8f56a8 ffff8801bcec9c18 ffff8801cb767968 [ 26.852721] ffffffff815676bb ffff8801ba8f56a8 0000000000000004 0000000000000000 [ 26.860700] Call Trace: [ 26.863260] [] dump_stack+0xc1/0x128 [ 26.868599] [] print_address_description+0x6c/0x234 [ 26.875434] [] kasan_report.cold.6+0x242/0x2fe [ 26.881638] [] ? tcp_connect+0x2633/0x2fa0 [ 26.887496] [] __asan_report_load4_noabort+0x14/0x20 [ 26.894221] [] tcp_connect+0x2633/0x2fa0 [ 26.899902] [] ? tcp_push_one+0xe0/0xe0 [ 26.905509] [] ? dst_release+0x70/0xb0 [ 26.911018] [] tcp_v4_connect+0x19f0/0x1c20 [ 26.916962] [] ? tcp_v4_inbound_md5_hash+0x3f0/0x3f0 [ 26.923689] [] ? __lock_is_held+0xa2/0xf0 [ 26.929459] [] __inet_stream_connect+0x6e0/0xbf0 [ 26.935836] [] ? mark_held_locks+0xc7/0x130 [ 26.941863] [] ? inet_bind+0x8b0/0x8b0 [ 26.947373] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 26.954192] [] ? lock_sock_nested+0x90/0x120 [ 26.960236] [] ? trace_hardirqs_on+0xd/0x10 [ 26.966197] [] ? __local_bh_enable_ip+0x6a/0xd0 [ 26.972488] [] inet_stream_connect+0x55/0xa0 [ 26.978519] [] SYSC_connect+0x1b8/0x300 [ 26.984114] [] ? vm_insert_mixed+0x200/0x200 [ 26.990144] [] ? SYSC_bind+0x280/0x280 [ 26.995743] [] ? do_futex+0x17c0/0x17c0 [ 27.001339] [] ? __do_page_fault+0x183/0xd50 [ 27.007370] [] SyS_connect+0x24/0x30 [ 27.012712] [] ? SyS_accept+0x30/0x30 [ 27.018136] [] do_syscall_64+0x1a6/0x490 [ 27.023819] [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 27.030712] [ 27.032312] Allocated by task 4155: [ 27.035913] save_stack_trace+0x16/0x20 [ 27.039858] save_stack+0x43/0xd0 [ 27.043282] kasan_kmalloc+0xc7/0xe0 [ 27.046966] kasan_slab_alloc+0x12/0x20 [ 27.050909] kmem_cache_alloc+0xbe/0x290 [ 27.054943] __alloc_skb+0xe6/0x600 [ 27.058549] sk_stream_alloc_skb+0xa3/0x5d0 [ 27.062841] tcp_sendmsg+0xe57/0x3040 [ 27.066613] inet_sendmsg+0x203/0x4d0 [ 27.070393] sock_sendmsg+0xcc/0x110 [ 27.074084] SYSC_sendto+0x21c/0x370 [ 27.077777] SyS_sendto+0x40/0x50 [ 27.081200] do_syscall_64+0x1a6/0x490 [ 27.085059] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 27.090129] [ 27.091731] Freed by task 4156: [ 27.094985] save_stack_trace+0x16/0x20 [ 27.098931] save_stack+0x43/0xd0 [ 27.102355] kasan_slab_free+0x72/0xc0 [ 27.106214] kmem_cache_free+0xbe/0x310 [ 27.110159] kfree_skbmem+0x7c/0x100 [ 27.113851] __kfree_skb+0x1d/0x20 [ 27.117361] tcp_connect+0xaaf/0x2fa0 [ 27.121133] tcp_v4_connect+0x19f0/0x1c20 [ 27.125252] __inet_stream_connect+0x6e0/0xbf0 [ 27.129803] inet_stream_connect+0x55/0xa0 [ 27.134009] SYSC_connect+0x1b8/0x300 [ 27.137781] SyS_connect+0x24/0x30 [ 27.141294] do_syscall_64+0x1a6/0x490 [ 27.145163] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 27.150235] [ 27.151854] The buggy address belongs to the object at ffff8801ba8f5680 [ 27.151854] which belongs to the cache skbuff_fclone_cache of size 456 [ 27.165178] The buggy address is located 40 bytes inside of [ 27.165178] 456-byte region [ffff8801ba8f5680, ffff8801ba8f5848) [ 27.176934] The buggy address belongs to the page: [ 27.181834] page:ffffea0006ea3d00 count:1 mapcount:0 mapping: (null) index:0x0 compound_mapcount: 0 [ 27.192011] flags: 0x8000000000004080(slab|head) [ 27.196734] page dumped because: kasan: bad access detected [ 27.202412] [ 27.204019] Memory state around the buggy address: [ 27.208923] ffff8801ba8f5580: fb fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc [ 27.216254] ffff8801ba8f5600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 27.223583] >ffff8801ba8f5680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 27.230912] ^ [ 27.235551] ffff8801ba8f5700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 27.242882] ffff8801ba8f5780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 27.250210] ================================================================== [ 27.257541] Disabling lock debugging due to kernel taint [ 27.264658] Kernel panic - not syncing: panic_on_warn set ... [ 27.264658] [ 27.272039] CPU: 1 PID: 4156 Comm: syz-executor383 Tainted: G B 4.9.103-g70c65e4 #37 [ 27.281026] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 27.290362] ffff8801cb767890 ffffffff81eb3469 ffffffff843c5d75 00000000ffffffff [ 27.298394] 0000000000000000 0000000000000001 ffff8801bcec9c18 ffff8801cb767950 [ 27.306431] ffffffff81421aa5 0000000041b58ab3 ffffffff843b94a8 ffffffff814218e6 [ 27.314470] Call Trace: [ 27.317048] [] dump_stack+0xc1/0x128 [ 27.322403] [] panic+0x1bf/0x3bc [ 27.327409] [] ? add_taint.cold.6+0x16/0x16 [ 27.333392] [] ? ___preempt_schedule+0x16/0x18 [ 27.339617] [] kasan_end_report+0x47/0x4f [ 27.345404] [] kasan_report.cold.6+0x76/0x2fe [ 27.351540] [] ? tcp_connect+0x2633/0x2fa0 [ 27.357416] [] __asan_report_load4_noabort+0x14/0x20 [ 27.364162] [] tcp_connect+0x2633/0x2fa0 [ 27.369865] [] ? tcp_push_one+0xe0/0xe0 [ 27.375476] [] ? dst_release+0x70/0xb0 [ 27.380989] [] tcp_v4_connect+0x19f0/0x1c20 [ 27.386935] [] ? tcp_v4_inbound_md5_hash+0x3f0/0x3f0 [ 27.393667] [] ? __lock_is_held+0xa2/0xf0 [ 27.399437] [] __inet_stream_connect+0x6e0/0xbf0 [ 27.405811] [] ? mark_held_locks+0xc7/0x130 [ 27.411753] [] ? inet_bind+0x8b0/0x8b0 [ 27.417261] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 27.424077] [] ? lock_sock_nested+0x90/0x120 [ 27.430117] [] ? trace_hardirqs_on+0xd/0x10 [ 27.436064] [] ? __local_bh_enable_ip+0x6a/0xd0 [ 27.442354] [] inet_stream_connect+0x55/0xa0 [ 27.448391] [] SYSC_connect+0x1b8/0x300 [ 27.453990] [] ? vm_insert_mixed+0x200/0x200 [ 27.460039] [] ? SYSC_bind+0x280/0x280 [ 27.465552] [] ? do_futex+0x17c0/0x17c0 [ 27.471147] [] ? __do_page_fault+0x183/0xd50 [ 27.477174] [] SyS_connect+0x24/0x30 [ 27.482524] [] ? SyS_accept+0x30/0x30 [ 27.487952] [] do_syscall_64+0x1a6/0x490 [ 27.493642] [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 27.501015] Dumping ftrace buffer: [ 27.504629] (ftrace buffer empty) [ 27.508312] Kernel Offset: disabled [ 27.511911] Rebooting in 86400 seconds..