[ OK ] Started Getty on tty2. [ OK ] Reached target Login Prompts. [ OK ] Started OpenBSD Secure Shell server. [ OK ] Listening on Load/Save RF Kill Switch Status /dev/rfkill Watch. [ OK ] Reached target Multi-User System. [ OK ] Reached target Graphical Interface. Starting Update UTMP about System Runlevel Changes... Starting Load/Save RF Kill Switch Status... [ OK ] Started Update UTMP about System Runlevel Changes. [ OK ] Started Load/Save RF Kill Switch Status. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.1.7' (ECDSA) to the list of known hosts. executing program executing program executing program executing program executing program executing program syzkaller login: [ 27.129644] netlink: 4 bytes leftover after parsing attributes in process `syz-executor273'. [ 27.139098] netlink: 4 bytes leftover after parsing attributes in process `syz-executor273'. executing program [ 27.185975] netlink: 4 bytes leftover after parsing attributes in process `syz-executor273'. [ 27.194740] netlink: 4 bytes leftover after parsing attributes in process `syz-executor273'. executing program [ 27.255583] netlink: 4 bytes leftover after parsing attributes in process `syz-executor273'. [ 27.264353] netlink: 4 bytes leftover after parsing attributes in process `syz-executor273'. executing program [ 27.304928] netlink: 4 bytes leftover after parsing attributes in process `syz-executor273'. [ 27.314656] netlink: 4 bytes leftover after parsing attributes in process `syz-executor273'. executing program [ 27.365147] netlink: 4 bytes leftover after parsing attributes in process `syz-executor273'. [ 27.374267] netlink: 4 bytes leftover after parsing attributes in process `syz-executor273'. 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 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 29.293348] ================================================================== [ 29.300791] BUG: KASAN: use-after-free in refcount_dec_not_one+0x9a/0xc0 [ 29.307616] Read of size 4 at addr ffff8880aa364118 by task syz-executor273/8295 [ 29.315131] [ 29.316740] CPU: 1 PID: 8295 Comm: syz-executor273 Not tainted 4.14.285-syzkaller #0 [ 29.324599] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 29.333936] Call Trace: [ 29.336505] dump_stack+0x1b2/0x281 [ 29.340113] print_address_description.cold+0x54/0x1d3 [ 29.345371] kasan_report_error.cold+0x8a/0x191 [ 29.350045] ? refcount_dec_not_one+0x9a/0xc0 [ 29.354551] __asan_report_load4_noabort+0x68/0x70 [ 29.359467] ? refcount_dec_not_one+0x9a/0xc0 [ 29.363941] refcount_dec_not_one+0x9a/0xc0 [ 29.368241] refcount_dec_and_mutex_lock+0x1a/0x60 [ 29.373150] nbd_genl_connect+0xce1/0x13e0 [ 29.377366] ? nbd_xmit_timeout+0x500/0x500 [ 29.381667] ? validate_nla+0x192/0x5e0 [ 29.385625] genl_family_rcv_msg+0x572/0xb20 [ 29.390023] ? genl_rcv+0x40/0x40 [ 29.393456] ? __ww_mutex_wakeup_for_backoff+0x210/0x210 [ 29.398889] ? __kmalloc_node_track_caller+0x4c/0x70 [ 29.403967] ? trace_hardirqs_on+0x10/0x10 [ 29.408181] genl_rcv_msg+0xaf/0x140 [ 29.411883] netlink_rcv_skb+0x125/0x390 [ 29.415927] ? genl_family_rcv_msg+0xb20/0xb20 [ 29.420487] ? netlink_ack+0x9a0/0x9a0 [ 29.424352] ? lock_acquire+0x170/0x3f0 [ 29.428306] genl_rcv+0x24/0x40 [ 29.431562] netlink_unicast+0x437/0x610 [ 29.435602] ? netlink_sendskb+0xd0/0xd0 [ 29.439644] ? __check_object_size+0x179/0x230 [ 29.444204] netlink_sendmsg+0x648/0xbc0 [ 29.448244] ? nlmsg_notify+0x1b0/0x1b0 [ 29.452196] ? kernel_recvmsg+0x210/0x210 [ 29.456339] ? security_socket_sendmsg+0x83/0xb0 [ 29.461071] ? nlmsg_notify+0x1b0/0x1b0 [ 29.465025] sock_sendmsg+0xb5/0x100 [ 29.468724] ___sys_sendmsg+0x6c8/0x800 [ 29.472674] ? copy_msghdr_from_user+0x3b0/0x3b0 [ 29.477409] ? netlink_dump+0xb90/0xb90 [ 29.481359] ? nlmsg_notify+0x1b0/0x1b0 [ 29.485327] ? security_socket_recvmsg+0x8b/0xc0 [ 29.490062] ? SyS_recvfrom+0x27f/0x340 [ 29.494013] ? SyS_send+0x40/0x40 [ 29.497444] ? vm_insert_page+0x7c0/0x7c0 [ 29.501568] ? __fdget+0x167/0x1f0 [ 29.505088] ? sockfd_lookup_light+0xb2/0x160 [ 29.509558] __sys_sendmsg+0xa3/0x120 [ 29.513354] ? SyS_shutdown+0x160/0x160 [ 29.517325] ? up_read+0x17/0x30 [ 29.520694] ? __do_page_fault+0x159/0xad0 [ 29.524944] SyS_sendmsg+0x27/0x40 [ 29.528469] ? __sys_sendmsg+0x120/0x120 [ 29.532512] do_syscall_64+0x1d5/0x640 [ 29.536391] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 29.541566] RIP: 0033:0x7feef162ca29 [ 29.545261] RSP: 002b:00007ffce9215808 EFLAGS: 00000246 ORIG_RAX: 000000000000002e [ 29.552954] RAX: ffffffffffffffda RBX: 00000000000f4240 RCX: 00007feef162ca29 [ 29.560200] RDX: 0000000024000040 RSI: 0000000020000380 RDI: 0000000000000003 [ 29.567451] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000001 [ 29.574707] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000000070d4 [ 29.581959] R13: 00007ffce921581c R14: 00007ffce9215830 R15: 00007ffce9215820 [ 29.589304] [ 29.590913] Allocated by task 8287: [ 29.594518] kasan_kmalloc+0xeb/0x160 [ 29.598299] kmem_cache_alloc_trace+0x131/0x3d0 [ 29.602943] nbd_dev_add+0x7c/0x800 [ 29.606546] nbd_genl_connect+0x3a4/0x13e0 [ 29.610762] genl_family_rcv_msg+0x572/0xb20 [ 29.615154] genl_rcv_msg+0xaf/0x140 [ 29.618850] netlink_rcv_skb+0x125/0x390 [ 29.622885] genl_rcv+0x24/0x40 [ 29.626144] netlink_unicast+0x437/0x610 [ 29.630185] netlink_sendmsg+0x648/0xbc0 [ 29.634224] sock_sendmsg+0xb5/0x100 [ 29.637912] ___sys_sendmsg+0x6c8/0x800 [ 29.641901] __sys_sendmsg+0xa3/0x120 [ 29.645687] SyS_sendmsg+0x27/0x40 [ 29.649212] do_syscall_64+0x1d5/0x640 [ 29.653094] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 29.658268] [ 29.659871] Freed by task 8295: [ 29.663134] kasan_slab_free+0xc3/0x1a0 [ 29.667088] kfree+0xc9/0x250 [ 29.670172] nbd_put.part.0+0x100/0x140 [ 29.674120] nbd_config_put+0x51c/0x6c0 [ 29.678134] nbd_genl_connect+0xcb9/0x13e0 [ 29.682346] genl_family_rcv_msg+0x572/0xb20 [ 29.686732] genl_rcv_msg+0xaf/0x140 [ 29.690421] netlink_rcv_skb+0x125/0x390 [ 29.694457] genl_rcv+0x24/0x40 [ 29.697715] netlink_unicast+0x437/0x610 [ 29.701750] netlink_sendmsg+0x648/0xbc0 [ 29.705783] sock_sendmsg+0xb5/0x100 [ 29.709488] ___sys_sendmsg+0x6c8/0x800 [ 29.713443] __sys_sendmsg+0xa3/0x120 [ 29.717218] SyS_sendmsg+0x27/0x40 [ 29.720750] do_syscall_64+0x1d5/0x640 [ 29.724619] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 29.729778] [ 29.731382] The buggy address belongs to the object at ffff8880aa364040 [ 29.731382] which belongs to the cache kmalloc-512 of size 512 [ 29.744013] The buggy address is located 216 bytes inside of [ 29.744013] 512-byte region [ffff8880aa364040, ffff8880aa364240) [ 29.755863] The buggy address belongs to the page: [ 29.760772] page:ffffea0002a8d900 count:1 mapcount:0 mapping:ffff8880aa364040 index:0x0 [ 29.768898] flags: 0xfff00000000100(slab) [ 29.773038] raw: 00fff00000000100 ffff8880aa364040 0000000000000000 0000000100000006 [ 29.780904] raw: ffffea0002a8cfa0 ffffea0002a98ce0 ffff88813fe74940 0000000000000000 [ 29.788754] page dumped because: kasan: bad access detected [ 29.794434] [ 29.796039] Memory state around the buggy address: [ 29.800942] ffff8880aa364000: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb [ 29.808289] ffff8880aa364080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 29.815622] >ffff8880aa364100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 29.822956] ^ [ 29.827088] ffff8880aa364180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 29.834420] ffff8880aa364200: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc [ 29.841770] ================================================================== [ 29.849111] Disabling lock debugging due to kernel taint [ 29.858107] Kernel panic - not syncing: panic_on_warn set ... [ 29.858107] [ 29.865467] CPU: 1 PID: 8295 Comm: syz-executor273 Tainted: G B 4.14.285-syzkaller #0 [ 29.874552] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 29.883895] Call Trace: [ 29.886477] dump_stack+0x1b2/0x281 [ 29.890100] panic+0x1f9/0x42d [ 29.893267] ? add_taint.cold+0x16/0x16 [ 29.897220] ? ___preempt_schedule+0x16/0x18 [ 29.901614] kasan_end_report+0x43/0x49 [ 29.905585] kasan_report_error.cold+0xa7/0x191 [ 29.910231] ? refcount_dec_not_one+0x9a/0xc0 [ 29.914721] __asan_report_load4_noabort+0x68/0x70 [ 29.919626] ? refcount_dec_not_one+0x9a/0xc0 [ 29.924102] refcount_dec_not_one+0x9a/0xc0 [ 29.928396] refcount_dec_and_mutex_lock+0x1a/0x60 [ 29.933302] nbd_genl_connect+0xce1/0x13e0 [ 29.937510] ? nbd_xmit_timeout+0x500/0x500 [ 29.941814] ? validate_nla+0x192/0x5e0 [ 29.945766] genl_family_rcv_msg+0x572/0xb20 [ 29.950150] ? genl_rcv+0x40/0x40 [ 29.953581] ? __ww_mutex_wakeup_for_backoff+0x210/0x210 [ 29.959020] ? __kmalloc_node_track_caller+0x4c/0x70 [ 29.964100] ? trace_hardirqs_on+0x10/0x10 [ 29.968310] genl_rcv_msg+0xaf/0x140 [ 29.972004] netlink_rcv_skb+0x125/0x390 [ 29.976040] ? genl_family_rcv_msg+0xb20/0xb20 [ 29.980597] ? netlink_ack+0x9a0/0x9a0 [ 29.984457] ? lock_acquire+0x170/0x3f0 [ 29.988406] genl_rcv+0x24/0x40 [ 29.991659] netlink_unicast+0x437/0x610 [ 29.995694] ? netlink_sendskb+0xd0/0xd0 [ 29.999731] ? __check_object_size+0x179/0x230 [ 30.004289] netlink_sendmsg+0x648/0xbc0 [ 30.008324] ? nlmsg_notify+0x1b0/0x1b0 [ 30.012272] ? kernel_recvmsg+0x210/0x210 [ 30.016397] ? security_socket_sendmsg+0x83/0xb0 [ 30.021142] ? nlmsg_notify+0x1b0/0x1b0 [ 30.025099] sock_sendmsg+0xb5/0x100 [ 30.028789] ___sys_sendmsg+0x6c8/0x800 [ 30.032737] ? copy_msghdr_from_user+0x3b0/0x3b0 [ 30.037466] ? netlink_dump+0xb90/0xb90 [ 30.041416] ? nlmsg_notify+0x1b0/0x1b0 [ 30.045363] ? security_socket_recvmsg+0x8b/0xc0 [ 30.050093] ? SyS_recvfrom+0x27f/0x340 [ 30.054055] ? SyS_send+0x40/0x40 [ 30.057485] ? vm_insert_page+0x7c0/0x7c0 [ 30.061606] ? __fdget+0x167/0x1f0 [ 30.065121] ? sockfd_lookup_light+0xb2/0x160 [ 30.069596] __sys_sendmsg+0xa3/0x120 [ 30.073380] ? SyS_shutdown+0x160/0x160 [ 30.077330] ? up_read+0x17/0x30 [ 30.080672] ? __do_page_fault+0x159/0xad0 [ 30.084888] SyS_sendmsg+0x27/0x40 [ 30.088409] ? __sys_sendmsg+0x120/0x120 [ 30.092445] do_syscall_64+0x1d5/0x640 [ 30.096314] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 30.101476] RIP: 0033:0x7feef162ca29 [ 30.105160] RSP: 002b:00007ffce9215808 EFLAGS: 00000246 ORIG_RAX: 000000000000002e [ 30.112838] RAX: ffffffffffffffda RBX: 00000000000f4240 RCX: 00007feef162ca29 [ 30.120099] RDX: 0000000024000040 RSI: 0000000020000380 RDI: 0000000000000003 [ 30.127344] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000001 [ 30.134588] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000000070d4 [ 30.141836] R13: 00007ffce921581c R14: 00007ffce9215830 R15: 00007ffce9215820 [ 30.149272] Kernel Offset: disabled [ 30.152879] Rebooting in 86400 seconds..