[....] Starting enhanced syslogd: rsyslogd[ 15.496356] audit: type=1400 audit(1521123970.084:5): avc: denied { syslog } for pid=4062 comm="rsyslogd" capability=34 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:system_r:kernel_t:s0 tclass=capability2 permissive=1 [?25l[?1c7[ ok 8[?25h[?0c. [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. Starting mcstransd: [....] Starting file context maintaining daemon: restorecond[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 19.337332] audit: type=1400 audit(1521123973.925:6): avc: denied { map } for pid=4203 comm="bash" path="/bin/bash" dev="sda1" ino=1457 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1 Warning: Permanently added '10.128.0.17' (ECDSA) to the list of known hosts. [ 93.422915] audit: type=1400 audit(1521124048.010:7): avc: denied { map } for pid=4220 comm="syzkaller185111" path="/root/syzkaller185111027" dev="sda1" ino=16481 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1 [ 93.433155] IPVS: ftp: loaded support on port[0] = 21 executing program executing program [ 93.474668] IPVS: ftp: loaded support on port[0] = 21 executing program executing program executing program executing program executing program executing program [ 93.499657] IPVS: ftp: loaded support on port[0] = 21 executing program executing program executing program executing program executing program executing program [ 93.527560] IPVS: ftp: loaded support on port[0] = 21 executing program executing program executing program executing program executing program executing program executing program [ 93.564888] IPVS: ftp: loaded support on port[0] = 21 executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 93.605748] IPVS: ftp: loaded support on port[0] = 21 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 [ 93.663284] IPVS: ftp: loaded support on port[0] = 21 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 [ 93.723354] l2tp_core: tunl 3: fd 3 wrong protocol, got 1, expected 17 [ 93.736886] IPVS: ftp: loaded support on port[0] = 21 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 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 [ 93.986977] l2tp_core: tunl 3: fd 3 wrong protocol, got 1, expected 17 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 [ 94.078831] l2tp_core: tunl 3: fd 3 wrong protocol, got 1, expected 17 [ 94.103206] l2tp_core: tunl 3: fd 4 wrong protocol, got 1, expected 17 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 [ 94.244310] l2tp_core: tunl 3: fd 3 wrong protocol, got 1, expected 17 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 [ 94.296142] l2tp_core: tunl 3: fd 3 wrong protocol, got 1, expected 17 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 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 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 94.690752] l2tp_core: tunl 3: fd 3 wrong protocol, got 1, expected 17 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 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 [ 95.014572] l2tp_core: tunl 3: fd 3 wrong protocol, got 1, expected 17 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 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 executing program executing program executing program executing program executing program executing program executing program [ 95.534703] l2tp_core: tunl 3: fd 3 wrong protocol, got 1, expected 17 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 [ 95.713975] l2tp_core: tunl 3: fd 6 wrong protocol, got 1, expected 17 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 95.794965] l2tp_core: tunl 3: fd 3 wrong protocol, got 1, expected 17 [ 95.802826] l2tp_core: tunl 3: fd 4 wrong protocol, got 1, expected 17 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 95.869753] l2tp_core: tunl 3: fd 3 wrong protocol, got 1, expected 17 [ 95.875122] l2tp_core: tunl 3: fd 3 wrong protocol, got 1, expected 17 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 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 [ 96.268504] l2tp_core: tunl 3: fd 3 wrong protocol, got 1, expected 17 executing program executing program executing program executing program executing program executing program executing program executing program [ 96.310074] l2tp_core: tunl 3: fd 3 wrong protocol, got 1, expected 17 [ 96.317218] l2tp_core: tunl 3: fd 4 wrong protocol, got 1, expected 17 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 96.397638] l2tp_core: tunl 3: fd 3 wrong protocol, got 1, expected 17 [ 96.427199] l2tp_core: tunl 3: fd 4 wrong protocol, got 1, expected 17 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 96.452493] l2tp_core: tunl 3: fd 3 wrong protocol, got 1, expected 17 executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 96.524831] l2tp_core: tunl 3: fd 3 wrong protocol, got 1, expected 17 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 [ 96.575086] l2tp_core: tunl 3: fd 6 wrong protocol, got 1, expected 17 [ 96.607533] l2tp_core: tunl 3: fd 3 wrong protocol, got 1, expected 17 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 [ 96.857332] l2tp_core: tunl 3: fd 3 wrong protocol, got 1, expected 17 executing program executing program executing program executing program executing program [ 96.936158] ================================================================== [ 96.943663] BUG: KASAN: use-after-free in pppol2tp_connect+0x1a98/0x1dd0 [ 96.950499] Read of size 8 at addr ffff8801ae8dea68 by task syzkaller185111/6389 [ 96.958014] [ 96.959631] CPU: 1 PID: 6389 Comm: syzkaller185111 Not tainted 4.16.0-rc5+ #354 [ 96.967059] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 96.976401] Call Trace: [ 96.978980] dump_stack+0x194/0x24d executing program executing program executing program executing program executing program [ 96.982602] ? arch_local_irq_restore+0x53/0x53 [ 96.987264] ? show_regs_print_info+0x18/0x18 [ 96.991758] ? lock_release+0xa40/0xa40 [ 96.995725] ? pppol2tp_connect+0x1a98/0x1dd0 [ 97.000217] print_address_description+0x73/0x250 [ 97.005052] ? pppol2tp_connect+0x1a98/0x1dd0 [ 97.009540] kasan_report+0x23c/0x360 [ 97.013343] __asan_report_load8_noabort+0x14/0x20 [ 97.018284] pppol2tp_connect+0x1a98/0x1dd0 [ 97.022619] ? pppol2tp_recv_payload_hook+0x1b0/0x1b0 [ 97.027810] ? selinux_netlbl_socket_connect+0x76/0x1b0 executing program [ 97.033173] ? selinux_socket_connect+0x311/0x730 [ 97.038013] ? lock_downgrade+0x980/0x980 [ 97.042161] ? selinux_socket_setsockopt+0x80/0x80 [ 97.047080] ? lock_release+0xa40/0xa40 [ 97.051046] ? check_same_owner+0x320/0x320 [ 97.055363] ? __check_object_size+0x8b/0x530 [ 97.059871] ? __might_sleep+0x95/0x190 [ 97.063862] ? security_socket_connect+0x89/0xb0 [ 97.068617] SYSC_connect+0x213/0x4a0 [ 97.072418] ? SYSC_bind+0x410/0x410 [ 97.076126] ? __handle_mm_fault+0x38c0/0x38c0 [ 97.080699] ? vmacache_find+0x5f/0x280 [ 97.084662] ? vmacache_update+0xfe/0x130 [ 97.088832] ? mm_fault_error+0x2c0/0x2c0 [ 97.092975] ? move_addr_to_kernel+0x60/0x60 [ 97.097389] SyS_connect+0x24/0x30 [ 97.100920] ? SyS_accept+0x30/0x30 [ 97.104545] do_syscall_64+0x281/0x940 [ 97.108425] ? __do_page_fault+0xc90/0xc90 [ 97.112649] ? _raw_spin_unlock_irq+0x27/0x70 [ 97.117140] ? finish_task_switch+0x1c1/0x7e0 [ 97.121631] ? syscall_return_slowpath+0x550/0x550 [ 97.126561] ? syscall_return_slowpath+0x2ac/0x550 [ 97.131483] ? prepare_exit_to_usermode+0x350/0x350 [ 97.136497] ? retint_user+0x18/0x18 [ 97.140212] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 97.145056] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 97.150247] RIP: 0033:0x446bf9 [ 97.153425] RSP: 002b:00007fa8b6eaedb8 EFLAGS: 00000293 ORIG_RAX: 000000000000002a [ 97.161130] RAX: ffffffffffffffda RBX: 00000000006e29e4 RCX: 0000000000446bf9 [ 97.168390] RDX: 0000000000000032 RSI: 0000000020e71000 RDI: 0000000000000006 [ 97.175649] RBP: 00000000006e29e0 R08: 0000000000000000 R09: 0000000000000000 [ 97.182917] R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 [ 97.190181] R13: 00007ffd59befb1f R14: 00007fa8b6eaf9c0 R15: 0000000000000009 [ 97.197476] [ 97.199092] Allocated by task 6389: [ 97.202712] save_stack+0x43/0xd0 [ 97.206154] kasan_kmalloc+0xad/0xe0 [ 97.209858] kasan_slab_alloc+0x12/0x20 [ 97.213823] kmem_cache_alloc+0x12e/0x760 [ 97.217968] sk_prot_alloc+0x65/0x2a0 [ 97.221763] sk_alloc+0x105/0x1440 [ 97.225296] inet6_create+0x44d/0x10f0 [ 97.229174] __sock_create+0x4d4/0x850 [ 97.233050] SyS_socket+0xeb/0x1d0 [ 97.236579] do_syscall_64+0x281/0x940 [ 97.240457] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 97.245627] [ 97.247239] Freed by task 28: [ 97.250335] save_stack+0x43/0xd0 [ 97.253779] __kasan_slab_free+0x11a/0x170 [ 97.258002] kasan_slab_free+0xe/0x10 [ 97.261795] kmem_cache_free+0x83/0x2a0 [ 97.265761] __sk_destruct+0x628/0x920 [ 97.269637] sk_destruct+0x47/0x80 [ 97.273165] __sk_free+0xf1/0x2b0 [ 97.276604] sk_free+0x2a/0x40 [ 97.279787] l2tp_tunnel_del_work+0x474/0x6a0 [ 97.284279] process_one_work+0xc47/0x1bb0 [ 97.288503] worker_thread+0x223/0x1990 [ 97.292469] kthread+0x33c/0x400 [ 97.295823] ret_from_fork+0x3a/0x50 [ 97.299521] [ 97.301135] The buggy address belongs to the object at ffff8801ae8de840 [ 97.301135] which belongs to the cache UDPv6 of size 1664 [ 97.313345] The buggy address is located 552 bytes inside of [ 97.313345] 1664-byte region [ffff8801ae8de840, ffff8801ae8deec0) [ 97.325291] The buggy address belongs to the page: [ 97.330205] page:ffffea0006ba3780 count:1 mapcount:0 mapping:ffff8801ae8de140 index:0x0 [ 97.338335] flags: 0x2fffc0000000100(slab) [ 97.342560] raw: 02fffc0000000100 ffff8801ae8de140 0000000000000000 0000000100000002 [ 97.350428] raw: ffffea0006b5f9e0 ffffea0006c2dd60 ffff8801d1af8d80 0000000000000000 [ 97.358304] page dumped because: kasan: bad access detected [ 97.364003] [ 97.365617] Memory state around the buggy address: [ 97.370535] ffff8801ae8de900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 97.377879] ffff8801ae8de980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb 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 [ 97.385228] >ffff8801ae8dea00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 97.392575] ^ [ 97.399315] ffff8801ae8dea80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 97.406660] ffff8801ae8deb00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 97.414004] ================================================================== [ 97.421344] Disabling lock debugging due to kernel taint [ 97.426987] Kernel panic - not syncing: panic_on_warn set ... [ 97.426987] [ 97.434346] CPU: 1 PID: 6389 Comm: syzkaller185111 Tainted: G B 4.16.0-rc5+ #354 [ 97.443076] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 97.452423] Call Trace: [ 97.455008] dump_stack+0x194/0x24d [ 97.458628] ? arch_local_irq_restore+0x53/0x53 [ 97.463288] ? kasan_end_report+0x32/0x50 [ 97.467426] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 97.472172] ? vsnprintf+0x1ed/0x1900 [ 97.475959] ? pppol2tp_connect+0x19d0/0x1dd0 [ 97.480448] panic+0x1e4/0x41c [ 97.483635] ? refcount_error_report+0x214/0x214 [ 97.488380] ? add_taint+0x1c/0x50 [ 97.491906] ? add_taint+0x1c/0x50 [ 97.495440] ? pppol2tp_connect+0x1a98/0x1dd0 [ 97.499922] kasan_end_report+0x50/0x50 [ 97.503883] kasan_report+0x149/0x360 [ 97.507679] __asan_report_load8_noabort+0x14/0x20 [ 97.512595] pppol2tp_connect+0x1a98/0x1dd0 [ 97.516914] ? pppol2tp_recv_payload_hook+0x1b0/0x1b0 [ 97.522099] ? selinux_netlbl_socket_connect+0x76/0x1b0 [ 97.527465] ? selinux_socket_connect+0x311/0x730 [ 97.532295] ? lock_downgrade+0x980/0x980 [ 97.536438] ? selinux_socket_setsockopt+0x80/0x80 [ 97.541358] ? lock_release+0xa40/0xa40 [ 97.545321] ? check_same_owner+0x320/0x320 [ 97.549635] ? __check_object_size+0x8b/0x530 [ 97.554122] ? __might_sleep+0x95/0x190 [ 97.558095] ? security_socket_connect+0x89/0xb0 [ 97.562842] SYSC_connect+0x213/0x4a0 [ 97.566635] ? SYSC_bind+0x410/0x410 [ 97.570337] ? __handle_mm_fault+0x38c0/0x38c0 [ 97.574909] ? vmacache_find+0x5f/0x280 [ 97.578869] ? vmacache_update+0xfe/0x130 [ 97.583020] ? mm_fault_error+0x2c0/0x2c0 [ 97.587162] ? move_addr_to_kernel+0x60/0x60 [ 97.591561] SyS_connect+0x24/0x30 [ 97.595090] ? SyS_accept+0x30/0x30 [ 97.598707] do_syscall_64+0x281/0x940 [ 97.602582] ? __do_page_fault+0xc90/0xc90 [ 97.606802] ? _raw_spin_unlock_irq+0x27/0x70 [ 97.611283] ? finish_task_switch+0x1c1/0x7e0 [ 97.615768] ? syscall_return_slowpath+0x550/0x550 [ 97.620689] ? syscall_return_slowpath+0x2ac/0x550 [ 97.625612] ? prepare_exit_to_usermode+0x350/0x350 [ 97.630620] ? retint_user+0x18/0x18 [ 97.634329] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 97.639165] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 97.644337] RIP: 0033:0x446bf9 [ 97.647513] RSP: 002b:00007fa8b6eaedb8 EFLAGS: 00000293 ORIG_RAX: 000000000000002a [ 97.655210] RAX: ffffffffffffffda RBX: 00000000006e29e4 RCX: 0000000000446bf9 [ 97.662465] RDX: 0000000000000032 RSI: 0000000020e71000 RDI: 0000000000000006 [ 97.669717] RBP: 00000000006e29e0 R08: 0000000000000000 R09: 0000000000000000 [ 97.676975] R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 [ 97.684231] R13: 00007ffd59befb1f R14: 00007fa8b6eaf9c0 R15: 0000000000000009 [ 97.691933] Dumping ftrace buffer: [ 97.695450] (ftrace buffer empty) [ 97.699130] Kernel Offset: disabled [ 97.702725] Rebooting in 86400 seconds..