[....] Starting enhanced syslogd: rsyslogd[ 17.240891] audit: type=1400 audit(1517509727.319:5): avc: denied { syslog } for pid=4007 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: [ 159.248759] audit: type=1400 audit(1517509869.327:6): avc: denied { map } for pid=4151 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 '10.128.0.47' (ECDSA) to the list of known hosts. executing program executing program executing program executing program executing program executing program executing program [ 165.464634] audit: type=1400 audit(1517509875.543:7): avc: denied { map } for pid=4164 comm="syzkaller905202" path="/root/syzkaller905202794" 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 [ 165.909465] ================================================================== [ 165.921071] BUG: KASAN: use-after-free in pppol2tp_connect+0x1a91/0x1dd0 [ 165.928098] Read of size 8 at addr ffff8801b3811368 by task syzkaller905202/4217 [ 165.935945] [ 165.937586] CPU: 1 PID: 4217 Comm: syzkaller905202 Not tainted 4.15.0+ #291 [ 165.944682] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 165.954039] Call Trace: [ 165.956639] dump_stack+0x194/0x257 [ 165.960281] ? arch_local_irq_restore+0x53/0x53 [ 165.965047] ? show_regs_print_info+0x18/0x18 [ 165.969579] ? lock_release+0xa40/0xa40 [ 165.973566] ? pppol2tp_connect+0x1a91/0x1dd0 [ 165.978073] print_address_description+0x73/0x250 [ 165.982923] ? pppol2tp_connect+0x1a91/0x1dd0 [ 165.987428] kasan_report+0x25b/0x340 [ 165.991260] __asan_report_load8_noabort+0x14/0x20 [ 165.996200] pppol2tp_connect+0x1a91/0x1dd0 [ 166.000545] ? pppol2tp_recv_payload_hook+0x1b0/0x1b0 [ 166.005752] ? selinux_netlbl_socket_connect+0x76/0x1b0 [ 166.011134] ? selinux_socket_connect+0x311/0x730 [ 166.015985] ? lock_downgrade+0x980/0x980 [ 166.020148] ? lock_downgrade+0x980/0x980 [ 166.024309] ? selinux_socket_setsockopt+0x80/0x80 [ 166.029247] ? lock_release+0xa40/0xa40 [ 166.033235] ? trace_event_raw_event_sched_switch+0x800/0x800 [ 166.039220] ? __check_object_size+0x25d/0x4f0 [ 166.043816] ? handle_mm_fault+0x476/0x930 [ 166.048067] ? __might_sleep+0x95/0x190 [ 166.052073] ? security_socket_connect+0x89/0xb0 [ 166.056842] SYSC_connect+0x213/0x4a0 [ 166.061863] ? SYSC_bind+0x410/0x410 [ 166.065603] ? do_page_fault+0xee/0x720 [ 166.069620] ? __do_page_fault+0xc90/0xc90 [ 166.073877] ? sock_map_fd+0x53/0x90 [ 166.077610] ? SyS_socket+0x12d/0x1d0 [ 166.081420] ? entry_SYSCALL_64_fastpath+0x5/0xa0 [ 166.086300] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 166.091328] SyS_connect+0x24/0x30 [ 166.094880] entry_SYSCALL_64_fastpath+0x29/0xa0 [ 166.099640] RIP: 0033:0x440ca9 [ 166.102824] RSP: 002b:00007ffe5fa13b98 EFLAGS: 00000207 ORIG_RAX: 000000000000002a [ 166.110526] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000440ca9 [ 166.117794] RDX: 000000000000002e RSI: 00000000205fafd2 RDI: 0000000000000004 [ 166.125060] RBP: 000000000002880c R08: 0000000000000000 R09: 0000000000000000 [ 166.132325] R10: 0000000000000000 R11: 0000000000000207 R12: 0000000000000000 [ 166.139596] R13: 0000000000000003 R14: 00000000006cf050 R15: 00000000004a264e [ 166.146899] [ 166.148525] Allocated by task 4215: [ 166.152148] save_stack+0x43/0xd0 [ 166.155585] kasan_kmalloc+0xad/0xe0 [ 166.159292] kasan_slab_alloc+0x12/0x20 [ 166.163241] kmem_cache_alloc+0x12e/0x760 [ 166.167362] sk_prot_alloc+0x65/0x2a0 [ 166.171148] sk_alloc+0x105/0x1440 [ 166.174668] inet6_create+0x44d/0x10f0 [ 166.178532] __sock_create+0x4d4/0x850 [ 166.182400] SyS_socket+0xeb/0x1d0 [ 166.185919] entry_SYSCALL_64_fastpath+0x29/0xa0 [ 166.190645] [ 166.192247] Freed by task 4217: [ 166.195500] save_stack+0x43/0xd0 [ 166.198944] kasan_slab_free+0x71/0xc0 [ 166.202805] kmem_cache_free+0x83/0x2a0 [ 166.206767] __sk_destruct+0x628/0x920 [ 166.210632] rcu_process_callbacks+0xd6c/0x17f0 [ 166.215284] __do_softirq+0x2d7/0xb85 [ 166.219065] [ 166.220671] The buggy address belongs to the object at ffff8801b3811140 [ 166.220671] which belongs to the cache UDPv6 of size 1664 [ 166.232873] The buggy address is located 552 bytes inside of [ 166.232873] 1664-byte region [ffff8801b3811140, ffff8801b38117c0) [ 166.244821] The buggy address belongs to the page: [ 166.249729] page:ffffea0006ce0440 count:1 mapcount:0 mapping:ffff8801b3811140 index:0x0 [ 166.257855] flags: 0x2fffc0000000100(slab) [ 166.262069] raw: 02fffc0000000100 ffff8801b3811140 0000000000000000 0000000100000002 [ 166.269926] raw: ffffea0006cce020 ffffea0006ca7320 ffff8801d29df800 0000000000000000 [ 166.277797] page dumped because: kasan: bad access detected [ 166.283481] [ 166.285080] Memory state around the buggy address: [ 166.289993] ffff8801b3811200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 166.297685] ffff8801b3811280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 166.305020] >ffff8801b3811300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 166.312354] ^ [ 166.319080] ffff8801b3811380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 166.326685] ffff8801b3811400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 166.334025] ================================================================== [ 166.341358] Disabling lock debugging due to kernel taint [ 166.346839] Kernel panic - not syncing: panic_on_warn set ... [ 166.346839] [ 166.354187] CPU: 1 PID: 4217 Comm: syzkaller905202 Tainted: G B 4.15.0+ #291 [ 166.362565] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 166.371902] Call Trace: [ 166.374471] dump_stack+0x194/0x257 [ 166.378081] ? arch_local_irq_restore+0x53/0x53 [ 166.382742] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 166.387481] ? vsnprintf+0x1ed/0x1900 [ 166.391277] ? pppol2tp_connect+0x19e0/0x1dd0 [ 166.395754] panic+0x1e4/0x41c [ 166.398924] ? refcount_error_report+0x214/0x214 [ 166.403660] ? add_taint+0x1c/0x50 [ 166.407180] ? add_taint+0x1c/0x50 [ 166.410698] ? pppol2tp_connect+0x1a91/0x1dd0 [ 166.415188] kasan_end_report+0x50/0x50 [ 166.419152] kasan_report+0x144/0x340 [ 166.422934] __asan_report_load8_noabort+0x14/0x20 [ 166.427846] pppol2tp_connect+0x1a91/0x1dd0 [ 166.432163] ? pppol2tp_recv_payload_hook+0x1b0/0x1b0 [ 166.437334] ? selinux_netlbl_socket_connect+0x76/0x1b0 [ 166.442682] ? selinux_socket_connect+0x311/0x730 [ 166.447516] ? lock_downgrade+0x980/0x980 [ 166.451644] ? lock_downgrade+0x980/0x980 [ 166.455775] ? selinux_socket_setsockopt+0x80/0x80 [ 166.460688] ? lock_release+0xa40/0xa40 [ 166.464643] ? trace_event_raw_event_sched_switch+0x800/0x800 [ 166.470512] ? __check_object_size+0x25d/0x4f0 [ 166.475078] ? handle_mm_fault+0x476/0x930 [ 166.479301] ? __might_sleep+0x95/0x190 [ 166.483268] ? security_socket_connect+0x89/0xb0 [ 166.488013] SYSC_connect+0x213/0x4a0 [ 166.491802] ? SYSC_bind+0x410/0x410 [ 166.495506] ? do_page_fault+0xee/0x720 [ 166.499472] ? __do_page_fault+0xc90/0xc90 [ 166.503699] ? sock_map_fd+0x53/0x90 [ 166.507396] ? SyS_socket+0x12d/0x1d0 [ 166.511179] ? entry_SYSCALL_64_fastpath+0x5/0xa0 [ 166.516031] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 166.521042] SyS_connect+0x24/0x30 [ 166.524563] entry_SYSCALL_64_fastpath+0x29/0xa0 [ 166.529302] RIP: 0033:0x440ca9 [ 166.532470] RSP: 002b:00007ffe5fa13b98 EFLAGS: 00000207 ORIG_RAX: 000000000000002a [ 166.540187] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000440ca9 [ 166.547478] RDX: 000000000000002e RSI: 00000000205fafd2 RDI: 0000000000000004 [ 166.554750] RBP: 000000000002880c R08: 0000000000000000 R09: 0000000000000000 [ 166.562022] R10: 0000000000000000 R11: 0000000000000207 R12: 0000000000000000 [ 166.569283] R13: 0000000000000003 R14: 00000000006cf050 R15: 00000000004a264e [ 166.576932] Dumping ftrace buffer: [ 166.580458] (ftrace buffer empty) [ 166.584144] Kernel Offset: disabled [ 166.587748] Rebooting in 86400 seconds..