[....] Starting enhanced syslogd: rsyslogd[ 13.023442] audit: type=1400 audit(1516432707.240:5): avc: denied { syslog } for pid=3498 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: [ 18.972907] audit: type=1400 audit(1516432713.189:6): avc: denied { map } for pid=3638 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 '10.128.15.245' (ECDSA) to the list of known hosts. executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 30.665720] audit: type=1400 audit(1516432724.882:7): avc: denied { map } for pid=3654 comm="syzkaller899919" path="/root/syzkaller899919443" 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 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 31.412297] ================================================================== [ 31.419704] BUG: KASAN: use-after-free in pppol2tp_connect+0x1a97/0x1dd0 [ 31.426517] Read of size 8 at addr ffff8801d7d492a8 by task syzkaller899919/4135 [ 31.434017] [ 31.435624] CPU: 0 PID: 4135 Comm: syzkaller899919 Not tainted 4.15.0-rc8+ #179 [ 31.443049] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 31.452381] Call Trace: [ 31.454949] dump_stack+0x194/0x257 [ 31.458550] ? arch_local_irq_restore+0x53/0x53 [ 31.463192] ? show_regs_print_info+0x18/0x18 [ 31.467662] ? retint_kernel+0x10/0x10 [ 31.471533] ? pppol2tp_connect+0x1a97/0x1dd0 [ 31.476003] print_address_description+0x73/0x250 [ 31.480822] ? pppol2tp_connect+0x1a97/0x1dd0 [ 31.485289] kasan_report+0x25b/0x340 [ 31.489071] __asan_report_load8_noabort+0x14/0x20 [ 31.493978] pppol2tp_connect+0x1a97/0x1dd0 [ 31.498293] ? pppol2tp_recv_payload_hook+0x1b0/0x1b0 [ 31.503469] ? selinux_netlbl_socket_connect+0x76/0x1b0 [ 31.508812] ? selinux_socket_connect+0x311/0x730 [ 31.513631] ? lock_downgrade+0x980/0x980 [ 31.517759] ? selinux_socket_setsockopt+0x80/0x80 [ 31.522658] ? lock_release+0xa40/0xa40 [ 31.526603] ? trace_event_raw_event_sched_switch+0x800/0x800 [ 31.532458] ? __check_object_size+0x25d/0x4f0 [ 31.537018] ? __might_sleep+0x95/0x190 [ 31.540974] ? security_socket_connect+0x89/0xb0 [ 31.545713] SYSC_connect+0x213/0x4a0 [ 31.549490] ? SYSC_bind+0x410/0x410 [ 31.553191] ? handle_mm_fault+0x410/0x8d0 [ 31.557404] ? __do_page_fault+0x32d/0xc90 [ 31.561609] ? __handle_mm_fault+0x3ce0/0x3ce0 [ 31.566164] ? vmacache_find+0x5f/0x280 [ 31.570116] ? up_read+0x1a/0x40 [ 31.573455] ? __do_page_fault+0x3d6/0xc90 [ 31.577670] SyS_connect+0x24/0x30 [ 31.581190] ? SyS_accept+0x30/0x30 [ 31.584801] do_fast_syscall_32+0x3ee/0xf9d [ 31.589105] ? do_int80_syscall_32+0x9d0/0x9d0 [ 31.593667] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 31.598409] ? syscall_return_slowpath+0x2ad/0x550 [ 31.603318] ? prepare_exit_to_usermode+0x340/0x340 [ 31.608308] ? retint_user+0x18/0x18 [ 31.611996] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 31.616815] entry_SYSENTER_compat+0x54/0x63 [ 31.621195] RIP: 0023:0xf7f81c79 [ 31.624528] RSP: 002b:00000000ffd51a8c EFLAGS: 00000286 ORIG_RAX: 000000000000016a [ 31.632293] RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000020e71000 [ 31.639538] RDX: 0000000000000032 RSI: 00000000080d68c0 RDI: 00000000080ebf84 [ 31.646783] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 [ 31.654030] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 31.661272] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 31.668530] [ 31.670128] Allocated by task 4131: [ 31.673729] save_stack+0x43/0xd0 [ 31.677162] kasan_kmalloc+0xad/0xe0 [ 31.680845] kasan_slab_alloc+0x12/0x20 [ 31.684792] kmem_cache_alloc+0x12e/0x760 [ 31.688911] sk_prot_alloc+0x65/0x2a0 [ 31.692682] sk_alloc+0x105/0x1410 [ 31.696200] inet6_create+0x44d/0x10f0 [ 31.700061] __sock_create+0x4d4/0x850 [ 31.703919] SyS_socket+0xeb/0x1d0 [ 31.707427] do_fast_syscall_32+0x3ee/0xf9d [ 31.711727] entry_SYSENTER_compat+0x54/0x63 [ 31.716102] [ 31.717699] Freed by task 4135: [ 31.720949] save_stack+0x43/0xd0 [ 31.724371] kasan_slab_free+0x71/0xc0 [ 31.728227] kmem_cache_free+0x83/0x2a0 [ 31.732170] __sk_destruct+0x622/0x910 [ 31.736026] sk_destruct+0x47/0x80 [ 31.739543] __sk_free+0x57/0x230 [ 31.742965] sk_free+0x2a/0x40 [ 31.746137] l2tp_session_free+0x21c/0x2b0 [ 31.750348] pppol2tp_session_destruct+0xd4/0x110 [ 31.755158] __sk_destruct+0xfd/0x910 [ 31.758929] sk_destruct+0x47/0x80 [ 31.762440] __sk_free+0x57/0x230 [ 31.765864] sk_free+0x2a/0x40 [ 31.769046] pppol2tp_put_sk+0x49/0x60 [ 31.772903] rcu_process_callbacks+0xd6c/0x17f0 [ 31.777544] __do_softirq+0x2d7/0xb85 [ 31.781314] [ 31.782927] The buggy address belongs to the object at ffff8801d7d49080 [ 31.782927] which belongs to the cache UDPv6 of size 1664 [ 31.795122] The buggy address is located 552 bytes inside of [ 31.795122] 1664-byte region [ffff8801d7d49080, ffff8801d7d49700) [ 31.807062] The buggy address belongs to the page: [ 31.811964] page:ffffea00075f5240 count:1 mapcount:0 mapping:ffff8801d7d49080 index:0x0 [ 31.820087] flags: 0x2fffc0000000100(slab) [ 31.824294] raw: 02fffc0000000100 ffff8801d7d49080 0000000000000000 0000000100000002 [ 31.832145] raw: ffffea000761be20 ffffea000760a820 ffff8801d329e9c0 0000000000000000 [ 31.840001] page dumped because: kasan: bad access detected [ 31.845679] [ 31.847273] Memory state around the buggy address: [ 31.852175] ffff8801d7d49180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 31.859512] ffff8801d7d49200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 31.866843] >ffff8801d7d49280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 31.874172] ^ [ 31.878813] ffff8801d7d49300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 31.886148] ffff8801d7d49380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 31.893476] ================================================================== [ 31.900807] Disabling lock debugging due to kernel taint [ 31.906383] Kernel panic - not syncing: panic_on_warn set ... [ 31.906383] [ 31.913727] CPU: 0 PID: 4135 Comm: syzkaller899919 Tainted: G B 4.15.0-rc8+ #179 [ 31.922451] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 31.931773] Call Trace: [ 31.934334] dump_stack+0x194/0x257 [ 31.937936] ? arch_local_irq_restore+0x53/0x53 [ 31.942586] ? kasan_end_report+0x32/0x50 [ 31.946710] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 31.951438] ? vsnprintf+0x1ed/0x1900 [ 31.955210] ? pppol2tp_connect+0x1a70/0x1dd0 [ 31.959677] panic+0x1e4/0x41c [ 31.962840] ? refcount_error_report+0x214/0x214 [ 31.967569] ? add_taint+0x1c/0x50 [ 31.971086] ? add_taint+0x1c/0x50 [ 31.974609] ? pppol2tp_connect+0x1a97/0x1dd0 [ 31.979074] kasan_end_report+0x50/0x50 [ 31.983022] kasan_report+0x144/0x340 [ 31.986796] __asan_report_load8_noabort+0x14/0x20 [ 31.991701] pppol2tp_connect+0x1a97/0x1dd0 [ 31.995995] ? pppol2tp_recv_payload_hook+0x1b0/0x1b0 [ 32.001176] ? selinux_netlbl_socket_connect+0x76/0x1b0 [ 32.006511] ? selinux_socket_connect+0x311/0x730 [ 32.011323] ? lock_downgrade+0x980/0x980 [ 32.015439] ? selinux_socket_setsockopt+0x80/0x80 [ 32.020344] ? lock_release+0xa40/0xa40 [ 32.024288] ? trace_event_raw_event_sched_switch+0x800/0x800 [ 32.030154] ? __check_object_size+0x25d/0x4f0 [ 32.034729] ? __might_sleep+0x95/0x190 [ 32.038680] ? security_socket_connect+0x89/0xb0 [ 32.043409] SYSC_connect+0x213/0x4a0 [ 32.047199] ? SYSC_bind+0x410/0x410 [ 32.050888] ? handle_mm_fault+0x410/0x8d0 [ 32.055094] ? __do_page_fault+0x32d/0xc90 [ 32.059301] ? __handle_mm_fault+0x3ce0/0x3ce0 [ 32.063859] ? vmacache_find+0x5f/0x280 [ 32.067809] ? up_read+0x1a/0x40 [ 32.071147] ? __do_page_fault+0x3d6/0xc90 [ 32.075358] SyS_connect+0x24/0x30 [ 32.078870] ? SyS_accept+0x30/0x30 [ 32.082491] do_fast_syscall_32+0x3ee/0xf9d [ 32.086787] ? do_int80_syscall_32+0x9d0/0x9d0 [ 32.091340] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 32.096080] ? syscall_return_slowpath+0x2ad/0x550 [ 32.100980] ? prepare_exit_to_usermode+0x340/0x340 [ 32.105970] ? retint_user+0x18/0x18 [ 32.109657] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 32.114475] entry_SYSENTER_compat+0x54/0x63 [ 32.118871] RIP: 0023:0xf7f81c79 [ 32.122205] RSP: 002b:00000000ffd51a8c EFLAGS: 00000286 ORIG_RAX: 000000000000016a [ 32.129883] RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000020e71000 [ 32.137125] RDX: 0000000000000032 RSI: 00000000080d68c0 RDI: 00000000080ebf84 [ 32.144375] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 [ 32.151614] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 32.158862] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 32.166484] Dumping ftrace buffer: [ 32.169993] (ftrace buffer empty) [ 32.173680] Kernel Offset: disabled [ 32.177284] Rebooting in 86400 seconds..