[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 19.325201] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 22.256750] random: sshd: uninitialized urandom read (32 bytes read) [ 22.590294] random: sshd: uninitialized urandom read (32 bytes read) [ 23.047546] random: sshd: uninitialized urandom read (32 bytes read) [ 37.837545] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.10.15' (ECDSA) to the list of known hosts. [ 43.257872] random: sshd: uninitialized urandom read (32 bytes read) [ 43.348693] IPVS: ftp: loaded support on port[0] = 21 [ 43.466037] bridge0: port 1(bridge_slave_0) entered blocking state [ 43.472495] bridge0: port 1(bridge_slave_0) entered disabled state [ 43.479691] device bridge_slave_0 entered promiscuous mode [ 43.495501] bridge0: port 2(bridge_slave_1) entered blocking state [ 43.501895] bridge0: port 2(bridge_slave_1) entered disabled state [ 43.508789] device bridge_slave_1 entered promiscuous mode [ 43.524219] IPv6: ADDRCONF(NETDEV_UP): veth0_to_bridge: link is not ready [ 43.539589] IPv6: ADDRCONF(NETDEV_UP): veth1_to_bridge: link is not ready [ 43.579716] bond0: Enslaving bond_slave_0 as an active interface with an up link [ 43.596646] bond0: Enslaving bond_slave_1 as an active interface with an up link [ 43.655152] IPv6: ADDRCONF(NETDEV_UP): team_slave_0: link is not ready [ 43.662389] team0: Port device team_slave_0 added [ 43.676046] IPv6: ADDRCONF(NETDEV_UP): team_slave_1: link is not ready [ 43.683251] team0: Port device team_slave_1 added [ 43.697344] IPv6: ADDRCONF(NETDEV_CHANGE): team_slave_0: link becomes ready [ 43.713048] IPv6: ADDRCONF(NETDEV_CHANGE): team_slave_1: link becomes ready [ 43.728856] IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_bridge: link becomes ready [ 43.746296] IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_bridge: link becomes ready RTNETLINK answers: Operation not supported RTNETLINK answers: No buffer space available RTNETLINK answers: Operation not supported [ 43.853272] bridge0: port 2(bridge_slave_1) entered blocking state [ 43.859726] bridge0: port 2(bridge_slave_1) entered forwarding state [ 43.866521] bridge0: port 1(bridge_slave_0) entered blocking state [ 43.872888] bridge0: port 1(bridge_slave_0) entered forwarding state RTNETLINK answers: Operation not supported RTNETLINK answers: Operation not supported RTNETLINK answers: Operation not supported RTNETLINK answers: Invalid argument RTNETLINK answers: Invalid argument RTNETLINK answers: Invalid argument [ 44.252908] IPv6: ADDRCONF(NETDEV_UP): bond0: link is not ready [ 44.259032] 8021q: adding VLAN 0 to HW filter on device bond0 [ 44.300060] IPv6: ADDRCONF(NETDEV_UP): veth0: link is not ready [ 44.340218] IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready [ 44.348108] IPv6: ADDRCONF(NETDEV_CHANGE): bond0: link becomes ready [ 44.382063] IPv6: ADDRCONF(NETDEV_UP): team0: link is not ready [ 44.388185] 8021q: adding VLAN 0 to HW filter on device team0 [ 44.413244] IPv6: ADDRCONF(NETDEV_CHANGE): team0: link becomes ready executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 45.883592] ================================================================== [ 45.891146] BUG: KASAN: use-after-free in ip6_hold_safe+0xbe/0x440 [ 45.897468] Write of size 4 at addr ffff8801ae370a80 by task syz-executor093/4766 [ 45.905084] [ 45.906723] CPU: 0 PID: 4766 Comm: syz-executor093 Not tainted 4.18.0-rc7+ #41 [ 45.914083] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 45.923433] Call Trace: [ 45.926023] dump_stack+0x1c9/0x2b4 [ 45.929652] ? dump_stack_print_info.cold.2+0x52/0x52 [ 45.934836] ? printk+0xa7/0xcf [ 45.938120] ? kmsg_dump_rewind_nolock+0xe4/0xe4 [ 45.942873] ? ip6_hold_safe+0xbe/0x440 [ 45.946829] print_address_description+0x6c/0x20b [ 45.951655] ? ip6_hold_safe+0xbe/0x440 [ 45.955613] kasan_report.cold.7+0x242/0x2fe [ 45.960029] check_memory_region+0x13e/0x1b0 [ 45.964425] kasan_check_write+0x14/0x20 [ 45.968467] ip6_hold_safe+0xbe/0x440 [ 45.972253] ? rt6_score_route+0x400/0x400 [ 45.976471] ? rcu_is_watching+0x8c/0x150 [ 45.980600] ? rcu_report_qs_rnp+0x7a0/0x7a0 [ 45.984992] ? ip6_pol_route+0x2fe/0x1250 [ 45.989132] ip6_pol_route+0x3ad/0x1250 [ 45.993095] ? ip6_pol_route_lookup+0x1120/0x1120 [ 45.997931] ? graph_lock+0x170/0x170 [ 46.001713] ? __lock_acquire+0x7fc/0x5020 [ 46.005936] ? find_held_lock+0x36/0x1c0 [ 46.009985] ip6_pol_route_output+0x54/0x70 [ 46.014294] fib6_rule_lookup+0x26e/0x700 [ 46.018424] ? ip6_pol_route_input+0x80/0x80 [ 46.022811] ? fib6_lookup+0x480/0x480 [ 46.026679] ? rcu_is_watching+0x8c/0x150 [ 46.030806] ? rcu_report_qs_rnp+0x7a0/0x7a0 [ 46.035203] ip6_route_output_flags+0x2c5/0x350 [ 46.039856] ip6_dst_lookup_tail+0x1278/0x1da0 [ 46.044428] ? ip6_dst_check+0x475/0xaf0 [ 46.048469] ? ip6_negative_advice+0x230/0x230 [ 46.053044] ? dst_output+0x180/0x180 [ 46.056839] ? lock_downgrade+0x8f0/0x8f0 [ 46.060970] ? rcu_is_watching+0x8c/0x150 [ 46.065098] ? rcu_report_qs_rnp+0x7a0/0x7a0 [ 46.069494] ? sk_dst_check+0x368/0x5d0 [ 46.073453] ip6_dst_lookup_flow+0xc8/0x270 [ 46.077768] ? ip6_dst_lookup+0x60/0x60 [ 46.081737] ip6_sk_dst_lookup_flow+0x5d2/0xac0 [ 46.086393] ? ip6_dst_lookup_flow+0x270/0x270 [ 46.090961] udpv6_sendmsg+0x20f9/0x35f0 [ 46.095006] ? ip_reply_glue_bits+0xc0/0xc0 [ 46.099326] ? udpv6_queue_rcv_skb+0x1530/0x1530 [ 46.104083] ? graph_lock+0x170/0x170 [ 46.107874] ? find_held_lock+0x36/0x1c0 [ 46.111928] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 46.117450] ? rw_copy_check_uvector+0x30d/0x3e0 [ 46.122205] ? find_held_lock+0x36/0x1c0 [ 46.126260] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 46.131786] ? import_iovec+0x269/0x470 [ 46.135754] ? dup_iter+0x270/0x270 [ 46.139383] inet_sendmsg+0x1a1/0x690 [ 46.143173] ? udpv6_queue_rcv_skb+0x1530/0x1530 [ 46.147916] ? inet_sendmsg+0x1a1/0x690 [ 46.151879] ? copy_msghdr_from_user+0x3c4/0x580 [ 46.156635] ? ipip_gro_receive+0x100/0x100 [ 46.160947] ? move_addr_to_kernel.part.20+0x100/0x100 [ 46.166210] ? security_socket_sendmsg+0x94/0xc0 [ 46.170949] ? ipip_gro_receive+0x100/0x100 [ 46.175266] sock_sendmsg+0xd5/0x120 [ 46.178975] ___sys_sendmsg+0x51d/0x930 [ 46.182951] ? copy_msghdr_from_user+0x580/0x580 [ 46.187696] ? __lock_acquire+0x7fc/0x5020 [ 46.191921] ? __fget_light+0x2f7/0x440 [ 46.195884] ? fget_raw+0x20/0x20 [ 46.199339] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 46.204866] ? sockfd_lookup_light+0xc5/0x160 [ 46.209349] __sys_sendmmsg+0x240/0x6f0 [ 46.213313] ? __ia32_sys_sendmsg+0xb0/0xb0 [ 46.217637] ? lock_downgrade+0x8f0/0x8f0 [ 46.221774] ? finish_task_switch+0x18a/0x870 [ 46.226263] ? kasan_check_read+0x11/0x20 [ 46.230392] ? do_raw_spin_unlock+0xa7/0x2f0 [ 46.234781] ? do_raw_spin_trylock+0x1c0/0x1c0 [ 46.239349] __x64_sys_sendmmsg+0x9d/0x100 [ 46.243567] do_syscall_64+0x1b9/0x820 [ 46.247434] ? finish_task_switch+0x1d3/0x870 [ 46.251912] ? syscall_return_slowpath+0x5e0/0x5e0 [ 46.256828] ? syscall_return_slowpath+0x31d/0x5e0 [ 46.261746] ? entry_SYSCALL_64_after_hwframe+0x59/0xbe [ 46.267096] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 46.271923] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 46.277098] RIP: 0033:0x446a29 [ 46.280267] Code: e8 ac b8 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 eb 08 fc ff c3 66 2e 0f 1f 84 00 00 00 00 [ 46.299449] RSP: 002b:00007f29b7885db8 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 [ 46.307146] RAX: ffffffffffffffda RBX: 00000000006dcc38 RCX: 0000000000446a29 [ 46.314399] RDX: 00000000000000b8 RSI: 0000000020001b00 RDI: 0000000000000003 [ 46.321652] RBP: 00000000006dcc30 R08: 00007f29b7886700 R09: 0000000000000000 [ 46.328918] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dcc3c [ 46.336170] R13: 00007ffd015a2a4f R14: 00007f29b78869c0 R15: 0000000000000001 [ 46.343428] [ 46.345051] Allocated by task 4688: [ 46.348679] save_stack+0x43/0xd0 [ 46.352112] kasan_kmalloc+0xc4/0xe0 [ 46.355810] kasan_slab_alloc+0x12/0x20 [ 46.359768] kmem_cache_alloc+0x12e/0x760 [ 46.363898] dst_alloc+0xbb/0x1d0 [ 46.367339] ip6_dst_alloc+0x35/0xa0 [ 46.371049] ip6_pol_route+0x83f/0x1250 [ 46.375008] ip6_pol_route_output+0x54/0x70 [ 46.379325] fib6_rule_lookup+0x26e/0x700 [ 46.383455] ip6_route_output_flags+0x2c5/0x350 [ 46.388106] ip6_dst_lookup_tail+0xe3f/0x1da0 [ 46.392587] ip6_dst_lookup_flow+0xc8/0x270 [ 46.396891] ip6_datagram_dst_update+0x75b/0xf80 [ 46.401628] __ip6_datagram_connect+0x5fe/0x1470 [ 46.406364] ip6_datagram_connect+0x2f/0x50 [ 46.410667] inet_dgram_connect+0x154/0x2e0 [ 46.414984] __sys_connect+0x37d/0x4c0 [ 46.418865] __x64_sys_connect+0x73/0xb0 [ 46.422917] do_syscall_64+0x1b9/0x820 [ 46.426789] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 46.431958] [ 46.433573] Freed by task 4765: [ 46.436838] save_stack+0x43/0xd0 [ 46.440271] __kasan_slab_free+0x11a/0x170 [ 46.444495] kasan_slab_free+0xe/0x10 [ 46.448277] kmem_cache_free+0x86/0x2d0 [ 46.452234] dst_destroy+0x267/0x3c0 [ 46.455932] dst_destroy_rcu+0x16/0x20 [ 46.459799] rcu_process_callbacks+0xed5/0x1850 [ 46.464454] __do_softirq+0x2e8/0xb17 [ 46.468229] [ 46.469837] The buggy address belongs to the object at ffff8801ae370a40 [ 46.469837] which belongs to the cache ip6_dst_cache of size 240 [ 46.482649] The buggy address is located 64 bytes inside of [ 46.482649] 240-byte region [ffff8801ae370a40, ffff8801ae370b30) [ 46.494416] The buggy address belongs to the page: [ 46.499329] page:ffffea0006b8dc00 count:1 mapcount:0 mapping:ffff8801cde9c640 index:0x0 [ 46.507451] flags: 0x2fffc0000000100(slab) [ 46.511668] raw: 02fffc0000000100 ffffea000754ef88 ffffea00073f20c8 ffff8801cde9c640 [ 46.519531] raw: 0000000000000000 ffff8801ae370040 000000010000000c 0000000000000000 [ 46.527385] page dumped because: kasan: bad access detected [ 46.533084] [ 46.534687] Memory state around the buggy address: [ 46.539595] ffff8801ae370980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc [ 46.546934] ffff8801ae370a00: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb [ 46.554280] >ffff8801ae370a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 46.561614] ^ [ 46.564960] ffff8801ae370b00: fb fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc [ 46.572299] ffff8801ae370b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 46.579634] ================================================================== [ 46.586978] Disabling lock debugging due to kernel taint [ 46.592456] Kernel panic - not syncing: panic_on_warn set ... [ 46.592456] [ 46.599821] CPU: 0 PID: 4766 Comm: syz-executor093 Tainted: G B 4.18.0-rc7+ #41 [ 46.608568] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 46.617903] Call Trace: [ 46.620479] dump_stack+0x1c9/0x2b4 [ 46.624094] ? dump_stack_print_info.cold.2+0x52/0x52 [ 46.629274] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 46.634026] panic+0x238/0x4e7 [ 46.637207] ? add_taint.cold.5+0x16/0x16 [ 46.641344] ? do_raw_spin_unlock+0xa7/0x2f0 [ 46.645750] ? do_raw_spin_unlock+0xa7/0x2f0 [ 46.650143] ? ip6_hold_safe+0xbe/0x440 [ 46.654103] kasan_end_report+0x47/0x4f [ 46.658064] kasan_report.cold.7+0x76/0x2fe [ 46.662368] check_memory_region+0x13e/0x1b0 [ 46.666765] kasan_check_write+0x14/0x20 [ 46.670807] ip6_hold_safe+0xbe/0x440 [ 46.674587] ? rt6_score_route+0x400/0x400 [ 46.678802] ? rcu_is_watching+0x8c/0x150 [ 46.682930] ? rcu_report_qs_rnp+0x7a0/0x7a0 [ 46.687319] ? ip6_pol_route+0x2fe/0x1250 [ 46.691448] ip6_pol_route+0x3ad/0x1250 [ 46.695413] ? ip6_pol_route_lookup+0x1120/0x1120 [ 46.700244] ? graph_lock+0x170/0x170 [ 46.704051] ? __lock_acquire+0x7fc/0x5020 [ 46.708279] ? find_held_lock+0x36/0x1c0 [ 46.712334] ip6_pol_route_output+0x54/0x70 [ 46.716636] fib6_rule_lookup+0x26e/0x700 [ 46.720775] ? ip6_pol_route_input+0x80/0x80 [ 46.725163] ? fib6_lookup+0x480/0x480 [ 46.729045] ? rcu_is_watching+0x8c/0x150 [ 46.733170] ? rcu_report_qs_rnp+0x7a0/0x7a0 [ 46.737572] ip6_route_output_flags+0x2c5/0x350 [ 46.742232] ip6_dst_lookup_tail+0x1278/0x1da0 [ 46.746799] ? ip6_dst_check+0x475/0xaf0 [ 46.750841] ? ip6_negative_advice+0x230/0x230 [ 46.755405] ? dst_output+0x180/0x180 [ 46.759203] ? lock_downgrade+0x8f0/0x8f0 [ 46.763332] ? rcu_is_watching+0x8c/0x150 [ 46.767460] ? rcu_report_qs_rnp+0x7a0/0x7a0 [ 46.771861] ? sk_dst_check+0x368/0x5d0 [ 46.775828] ip6_dst_lookup_flow+0xc8/0x270 [ 46.780140] ? ip6_dst_lookup+0x60/0x60 [ 46.784096] ip6_sk_dst_lookup_flow+0x5d2/0xac0 [ 46.788747] ? ip6_dst_lookup_flow+0x270/0x270 [ 46.793312] udpv6_sendmsg+0x20f9/0x35f0 [ 46.797369] ? ip_reply_glue_bits+0xc0/0xc0 [ 46.801688] ? udpv6_queue_rcv_skb+0x1530/0x1530 [ 46.806438] ? graph_lock+0x170/0x170 [ 46.810235] ? find_held_lock+0x36/0x1c0 [ 46.814281] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 46.819798] ? rw_copy_check_uvector+0x30d/0x3e0 [ 46.824545] ? find_held_lock+0x36/0x1c0 [ 46.828592] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 46.834109] ? import_iovec+0x269/0x470 [ 46.838064] ? dup_iter+0x270/0x270 [ 46.841672] inet_sendmsg+0x1a1/0x690 [ 46.845464] ? udpv6_queue_rcv_skb+0x1530/0x1530 [ 46.850199] ? inet_sendmsg+0x1a1/0x690 [ 46.854164] ? copy_msghdr_from_user+0x3c4/0x580 [ 46.858910] ? ipip_gro_receive+0x100/0x100 [ 46.863213] ? move_addr_to_kernel.part.20+0x100/0x100 [ 46.868470] ? security_socket_sendmsg+0x94/0xc0 [ 46.873205] ? ipip_gro_receive+0x100/0x100 [ 46.877516] sock_sendmsg+0xd5/0x120 [ 46.881209] ___sys_sendmsg+0x51d/0x930 [ 46.885168] ? copy_msghdr_from_user+0x580/0x580 [ 46.889904] ? __lock_acquire+0x7fc/0x5020 [ 46.894121] ? __fget_light+0x2f7/0x440 [ 46.898076] ? fget_raw+0x20/0x20 [ 46.901516] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 46.907040] ? sockfd_lookup_light+0xc5/0x160 [ 46.911516] __sys_sendmmsg+0x240/0x6f0 [ 46.915472] ? __ia32_sys_sendmsg+0xb0/0xb0 [ 46.919781] ? lock_downgrade+0x8f0/0x8f0 [ 46.923907] ? finish_task_switch+0x18a/0x870 [ 46.928386] ? kasan_check_read+0x11/0x20 [ 46.932515] ? do_raw_spin_unlock+0xa7/0x2f0 [ 46.936902] ? do_raw_spin_trylock+0x1c0/0x1c0 [ 46.941464] __x64_sys_sendmmsg+0x9d/0x100 [ 46.945680] do_syscall_64+0x1b9/0x820 [ 46.949554] ? finish_task_switch+0x1d3/0x870 [ 46.954059] ? syscall_return_slowpath+0x5e0/0x5e0 [ 46.959014] ? syscall_return_slowpath+0x31d/0x5e0 [ 46.963932] ? entry_SYSCALL_64_after_hwframe+0x59/0xbe [ 46.969285] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 46.974118] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 46.979296] RIP: 0033:0x446a29 [ 46.982460] Code: e8 ac b8 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 eb 08 fc ff c3 66 2e 0f 1f 84 00 00 00 00 [ 47.001582] RSP: 002b:00007f29b7885db8 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 [ 47.009280] RAX: ffffffffffffffda RBX: 00000000006dcc38 RCX: 0000000000446a29 [ 47.016529] RDX: 00000000000000b8 RSI: 0000000020001b00 RDI: 0000000000000003 [ 47.023777] RBP: 00000000006dcc30 R08: 00007f29b7886700 R09: 0000000000000000 [ 47.031031] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dcc3c [ 47.038281] R13: 00007ffd015a2a4f R14: 00007f29b78869c0 R15: 0000000000000001 [ 47.046091] Dumping ftrace buffer: [ 47.049610] (ftrace buffer empty) [ 47.053293] Kernel Offset: disabled [ 47.056897] Rebooting in 86400 seconds..