[?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. [ 18.168236] audit: type=1400 audit(1518877773.598:6): avc: denied { map } for pid=4158 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 Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.0.17' (ECDSA) to the list of known hosts. executing program executing program executing program executing program syzkaller login: [ 24.453163] audit: type=1400 audit(1518877779.882:7): avc: denied { map } for pid=4172 comm="syzkaller565865" path="/root/syzkaller565865214" 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 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 26.728299] ================================================================== [ 26.735754] BUG: KASAN: use-after-free in pppol2tp_connect+0x1a91/0x1dd0 [ 26.742566] Read of size 8 at addr ffff8801af575368 by task syzkaller565865/4685 [ 26.750071] [ 26.751673] CPU: 1 PID: 4685 Comm: syzkaller565865 Not tainted 4.16.0-rc1+ #226 [ 26.759089] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 26.768410] Call Trace: [ 26.770974] dump_stack+0x194/0x257 [ 26.774580] ? arch_local_irq_restore+0x53/0x53 [ 26.779222] ? show_regs_print_info+0x18/0x18 [ 26.783699] ? pppol2tp_connect+0x1a91/0x1dd0 [ 26.788168] print_address_description+0x73/0x250 [ 26.792986] ? pppol2tp_connect+0x1a91/0x1dd0 [ 26.797457] kasan_report+0x23b/0x360 [ 26.801233] __asan_report_load8_noabort+0x14/0x20 [ 26.806134] pppol2tp_connect+0x1a91/0x1dd0 [ 26.810435] ? pppol2tp_recv_payload_hook+0x1b0/0x1b0 [ 26.815603] ? selinux_netlbl_socket_connect+0x76/0x1b0 [ 26.820955] ? selinux_socket_connect+0x311/0x730 [ 26.825776] ? lock_downgrade+0x980/0x980 [ 26.829898] ? selinux_socket_setsockopt+0x80/0x80 [ 26.834798] ? lock_release+0xa40/0xa40 [ 26.838747] ? trace_event_raw_event_sched_switch+0x810/0x810 [ 26.844603] ? __check_object_size+0x8b/0x530 [ 26.849075] ? __might_sleep+0x95/0x190 [ 26.853042] ? security_socket_connect+0x89/0xb0 [ 26.857789] SYSC_connect+0x213/0x4a0 [ 26.861571] ? SYSC_bind+0x410/0x410 [ 26.865261] ? handle_mm_fault+0x43b/0x970 [ 26.869471] ? __handle_mm_fault+0x3ce0/0x3ce0 [ 26.874029] ? vmacache_find+0x5f/0x280 [ 26.877995] ? up_read+0x1a/0x40 [ 26.881341] ? __do_page_fault+0x3d6/0xc90 [ 26.885558] SyS_connect+0x24/0x30 [ 26.889072] ? SyS_accept+0x30/0x30 [ 26.892671] do_fast_syscall_32+0x3ec/0xf9f [ 26.896974] ? do_int80_syscall_32+0x9c0/0x9c0 [ 26.901526] ? mmdrop+0x18/0x30 [ 26.904779] ? finish_task_switch+0x279/0x860 [ 26.909250] ? syscall_return_slowpath+0x2ac/0x550 [ 26.914155] ? prepare_exit_to_usermode+0x350/0x350 [ 26.919149] ? retint_user+0x18/0x18 [ 26.922840] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 26.927664] entry_SYSENTER_compat+0x70/0x7f [ 26.932045] RIP: 0023:0xf7f42c79 [ 26.935379] RSP: 002b:00000000f7f3e1fc EFLAGS: 00000283 ORIG_RAX: 000000000000016a [ 26.943059] RAX: ffffffffffffffda RBX: 0000000000000008 RCX: 0000000020e71000 [ 26.950298] RDX: 0000000000000032 RSI: 0000000000000000 RDI: 0000000000000000 [ 26.957539] RBP: 00000000003d0f00 R08: 0000000000000000 R09: 0000000000000000 [ 26.964781] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 26.972029] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 26.979819] [ 26.981423] Allocated by task 4685: [ 26.985032] save_stack+0x43/0xd0 [ 26.988459] kasan_kmalloc+0xad/0xe0 [ 26.992150] kasan_slab_alloc+0x12/0x20 [ 26.996099] kmem_cache_alloc+0x12e/0x760 [ 27.000219] sk_prot_alloc+0x65/0x2a0 [ 27.003991] sk_alloc+0x105/0x1440 [ 27.007510] inet6_create+0x44d/0x10f0 [ 27.011371] __sock_create+0x4d4/0x850 [ 27.015230] SyS_socket+0xeb/0x1d0 [ 27.018745] do_fast_syscall_32+0x3ec/0xf9f [ 27.023047] entry_SYSENTER_compat+0x70/0x7f [ 27.027426] [ 27.029031] Freed by task 4685: [ 27.032286] save_stack+0x43/0xd0 [ 27.035710] __kasan_slab_free+0x11a/0x170 [ 27.039916] kasan_slab_free+0xe/0x10 [ 27.043689] kmem_cache_free+0x83/0x2a0 [ 27.047635] __sk_destruct+0x628/0x920 [ 27.051494] sk_destruct+0x47/0x80 [ 27.055011] __sk_free+0xf1/0x2b0 [ 27.058443] sk_free+0x2a/0x40 [ 27.061611] l2tp_session_free+0x21c/0x2b0 [ 27.065817] pppol2tp_session_destruct+0xd4/0x110 [ 27.070629] __sk_destruct+0xfd/0x920 [ 27.074401] sk_destruct+0x47/0x80 [ 27.077912] __sk_free+0xf1/0x2b0 [ 27.081334] sk_free+0x2a/0x40 [ 27.084497] pppol2tp_put_sk+0x49/0x60 [ 27.088356] rcu_process_callbacks+0xd6c/0x17f0 [ 27.092996] __do_softirq+0x2d7/0xb85 [ 27.096771] [ 27.098371] The buggy address belongs to the object at ffff8801af575140 [ 27.098371] which belongs to the cache UDPv6 of size 1664 [ 27.110564] The buggy address is located 552 bytes inside of [ 27.110564] 1664-byte region [ffff8801af575140, ffff8801af5757c0) [ 27.122497] The buggy address belongs to the page: [ 27.127398] page:ffffea0006bd5d40 count:1 mapcount:0 mapping:ffff8801af575140 index:0x0 [ 27.135515] flags: 0x2fffc0000000100(slab) [ 27.139733] raw: 02fffc0000000100 ffff8801af575140 0000000000000000 0000000100000002 [ 27.147603] raw: ffffea0006b4aae0 ffffea0006b7a0a0 ffff8801d50b23c0 0000000000000000 [ 27.155461] page dumped because: kasan: bad access detected [ 27.161147] [ 27.162747] Memory state around the buggy address: [ 27.167651] ffff8801af575200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 27.174980] ffff8801af575280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 27.182308] >ffff8801af575300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 27.189635] ^ [ 27.196355] ffff8801af575380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 27.203685] ffff8801af575400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 27.211016] ================================================================== [ 27.218350] Disabling lock debugging due to kernel taint [ 27.223862] Kernel panic - not syncing: panic_on_warn set ... [ 27.223862] [ 27.231212] CPU: 1 PID: 4685 Comm: syzkaller565865 Tainted: G B 4.16.0-rc1+ #226 [ 27.239932] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 27.249255] Call Trace: [ 27.251824] dump_stack+0x194/0x257 [ 27.255428] ? arch_local_irq_restore+0x53/0x53 [ 27.260067] ? kasan_end_report+0x32/0x50 [ 27.264196] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 27.268927] ? vsnprintf+0x1ed/0x1900 [ 27.272702] ? pppol2tp_connect+0x19b0/0x1dd0 [ 27.277171] panic+0x1e4/0x41c [ 27.280333] ? refcount_error_report+0x214/0x214 [ 27.285060] ? add_taint+0x1c/0x50 [ 27.288568] ? add_taint+0x1c/0x50 [ 27.292079] ? pppol2tp_connect+0x1a91/0x1dd0 [ 27.296543] kasan_end_report+0x50/0x50 [ 27.300486] kasan_report+0x148/0x360 [ 27.304257] __asan_report_load8_noabort+0x14/0x20 [ 27.309160] pppol2tp_connect+0x1a91/0x1dd0 [ 27.313469] ? pppol2tp_recv_payload_hook+0x1b0/0x1b0 [ 27.318637] ? selinux_netlbl_socket_connect+0x76/0x1b0 [ 27.323975] ? selinux_socket_connect+0x311/0x730 [ 27.328792] ? lock_downgrade+0x980/0x980 [ 27.332912] ? selinux_socket_setsockopt+0x80/0x80 [ 27.337813] ? lock_release+0xa40/0xa40 [ 27.341760] ? trace_event_raw_event_sched_switch+0x810/0x810 [ 27.347619] ? __check_object_size+0x8b/0x530 [ 27.352091] ? __might_sleep+0x95/0x190 [ 27.356044] ? security_socket_connect+0x89/0xb0 [ 27.360773] SYSC_connect+0x213/0x4a0 [ 27.364548] ? SYSC_bind+0x410/0x410 [ 27.368234] ? handle_mm_fault+0x43b/0x970 [ 27.372443] ? __handle_mm_fault+0x3ce0/0x3ce0 [ 27.376997] ? vmacache_find+0x5f/0x280 [ 27.380954] ? up_read+0x1a/0x40 [ 27.384297] ? __do_page_fault+0x3d6/0xc90 [ 27.388512] SyS_connect+0x24/0x30 [ 27.392029] ? SyS_accept+0x30/0x30 [ 27.395629] do_fast_syscall_32+0x3ec/0xf9f [ 27.399922] ? do_int80_syscall_32+0x9c0/0x9c0 [ 27.404473] ? mmdrop+0x18/0x30 [ 27.407725] ? finish_task_switch+0x279/0x860 [ 27.412192] ? syscall_return_slowpath+0x2ac/0x550 [ 27.417090] ? prepare_exit_to_usermode+0x350/0x350 [ 27.422080] ? retint_user+0x18/0x18 [ 27.425765] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 27.430583] entry_SYSENTER_compat+0x70/0x7f [ 27.434963] RIP: 0023:0xf7f42c79 [ 27.438296] RSP: 002b:00000000f7f3e1fc EFLAGS: 00000283 ORIG_RAX: 000000000000016a [ 27.445974] RAX: ffffffffffffffda RBX: 0000000000000008 RCX: 0000000020e71000 [ 27.453215] RDX: 0000000000000032 RSI: 0000000000000000 RDI: 0000000000000000 [ 27.460453] RBP: 00000000003d0f00 R08: 0000000000000000 R09: 0000000000000000 [ 27.467692] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 27.474933] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 27.482632] Dumping ftrace buffer: [ 27.486144] (ftrace buffer empty) [ 27.489823] Kernel Offset: disabled [ 27.493419] Rebooting in 86400 seconds..