[....] Starting enhanced syslogd: rsyslogd[ 14.677657] audit: type=1400 audit(1519128106.875:5): avc: denied { syslog } for pid=3939 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 OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting file context maintaining daemon: restorecond[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 19.416451] audit: type=1400 audit(1519128111.614:6): avc: denied { map } for pid=4079 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 '10.128.15.204' (ECDSA) to the list of known hosts. executing program executing program executing program executing program executing program executing program [ 40.219774] audit: type=1400 audit(1519128132.417:7): avc: denied { map } for pid=4096 comm="syzkaller460196" path="/root/syzkaller460196587" 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 [ 41.313299] ================================================================== [ 41.320765] BUG: KASAN: use-after-free in pppol2tp_connect+0x1a91/0x1dd0 [ 41.327580] Read of size 8 at addr ffff8801be714ee8 by task syzkaller460196/4452 [ 41.335087] [ 41.336689] CPU: 0 PID: 4452 Comm: syzkaller460196 Not tainted 4.16.0-rc2+ #234 [ 41.344107] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 41.353434] Call Trace: [ 41.356006] dump_stack+0x194/0x257 [ 41.359611] ? arch_local_irq_restore+0x53/0x53 [ 41.364257] ? show_regs_print_info+0x18/0x18 [ 41.368732] ? lock_release+0xa40/0xa40 [ 41.372680] ? pppol2tp_connect+0x1a91/0x1dd0 [ 41.377150] print_address_description+0x73/0x250 [ 41.381973] ? pppol2tp_connect+0x1a91/0x1dd0 [ 41.386442] kasan_report+0x23b/0x360 [ 41.390223] __asan_report_load8_noabort+0x14/0x20 [ 41.395127] pppol2tp_connect+0x1a91/0x1dd0 [ 41.399432] ? pppol2tp_recv_payload_hook+0x1b0/0x1b0 [ 41.404598] ? selinux_netlbl_socket_connect+0x76/0x1b0 [ 41.409941] ? selinux_socket_connect+0x311/0x730 [ 41.414756] ? lock_downgrade+0x980/0x980 [ 41.418881] ? selinux_socket_setsockopt+0x80/0x80 [ 41.423782] ? lock_release+0xa40/0xa40 [ 41.427729] ? trace_event_raw_event_sched_switch+0x810/0x810 [ 41.433589] ? __check_object_size+0x8b/0x530 [ 41.438065] ? __might_sleep+0x95/0x190 [ 41.442024] ? security_socket_connect+0x89/0xb0 [ 41.446759] SYSC_connect+0x213/0x4a0 [ 41.450535] ? SYSC_bind+0x410/0x410 [ 41.454235] ? __handle_mm_fault+0x3ce0/0x3ce0 [ 41.458787] ? vmacache_find+0x5f/0x280 [ 41.462734] ? vmacache_update+0xfe/0x130 [ 41.466884] ? mm_fault_error+0x2c0/0x2c0 [ 41.471008] ? move_addr_to_kernel+0x60/0x60 [ 41.475386] ? do_raw_spin_trylock+0x190/0x190 [ 41.479945] ? SyS_accept+0x30/0x30 [ 41.483547] SyS_connect+0x24/0x30 [ 41.487066] do_syscall_64+0x280/0x940 [ 41.490926] ? __do_page_fault+0xc90/0xc90 [ 41.495147] ? finish_task_switch+0x1c0/0x860 [ 41.499613] ? finish_task_switch+0x181/0x860 [ 41.504080] ? syscall_return_slowpath+0x550/0x550 [ 41.508987] ? syscall_return_slowpath+0x2ac/0x550 [ 41.513890] ? prepare_exit_to_usermode+0x350/0x350 [ 41.518881] ? retint_user+0x18/0x18 [ 41.522571] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 41.527390] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 41.532551] RIP: 0033:0x4468f9 [ 41.535712] RSP: 002b:00007fa3c88f8db8 EFLAGS: 00000246 ORIG_RAX: 000000000000002a [ 41.543394] RAX: ffffffffffffffda RBX: 00000000006e29c4 RCX: 00000000004468f9 [ 41.550635] RDX: 000000000000002e RSI: 0000000020348fd2 RDI: 0000000000000004 [ 41.557877] RBP: 00000000006e29c0 R08: 0000000000000000 R09: 0000000000000000 [ 41.565120] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 [ 41.572362] R13: 00007fff15fe827f R14: 00007fa3c88f99c0 R15: 0000000000000003 [ 41.579622] [ 41.581223] Allocated by task 4449: [ 41.584824] save_stack+0x43/0xd0 [ 41.588250] kasan_kmalloc+0xad/0xe0 [ 41.591941] kasan_slab_alloc+0x12/0x20 [ 41.595891] kmem_cache_alloc+0x12e/0x760 [ 41.600026] sk_prot_alloc+0x65/0x2a0 [ 41.603811] sk_alloc+0x105/0x1440 [ 41.607326] inet_create+0x47c/0xf50 [ 41.611013] __sock_create+0x4d4/0x850 [ 41.614869] SyS_socket+0xeb/0x1d0 [ 41.618380] do_syscall_64+0x280/0x940 [ 41.622242] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 41.627399] [ 41.629000] Freed by task 4452: [ 41.632252] save_stack+0x43/0xd0 [ 41.635676] __kasan_slab_free+0x11a/0x170 [ 41.639895] kasan_slab_free+0xe/0x10 [ 41.643935] kmem_cache_free+0x83/0x2a0 [ 41.647883] __sk_destruct+0x628/0x920 [ 41.651741] sk_destruct+0x47/0x80 [ 41.655252] __sk_free+0xf1/0x2b0 [ 41.658678] sk_free+0x2a/0x40 [ 41.661846] l2tp_session_free+0x21c/0x2b0 [ 41.666051] pppol2tp_session_destruct+0xd4/0x110 [ 41.670867] __sk_destruct+0xfd/0x920 [ 41.674638] sk_destruct+0x47/0x80 [ 41.678149] __sk_free+0xf1/0x2b0 [ 41.681571] sk_free+0x2a/0x40 [ 41.684734] pppol2tp_put_sk+0x49/0x60 [ 41.688593] rcu_process_callbacks+0xd6c/0x17f0 [ 41.693234] __do_softirq+0x2d7/0xb85 [ 41.697002] [ 41.698601] The buggy address belongs to the object at ffff8801be714cc0 [ 41.698601] which belongs to the cache UDP of size 1472 [ 41.710622] The buggy address is located 552 bytes inside of [ 41.710622] 1472-byte region [ffff8801be714cc0, ffff8801be715280) [ 41.722563] The buggy address belongs to the page: [ 41.727464] page:ffffea0006f9c500 count:1 mapcount:0 mapping:ffff8801be714040 index:0x0 compound_mapcount: 0 [ 41.737405] flags: 0x2fffc0000008100(slab|head) [ 41.742047] raw: 02fffc0000008100 ffff8801be714040 0000000000000000 0000000100000005 [ 41.749899] raw: ffffea0006f402a0 ffff8801d5e12c48 ffff8801d5e11940 0000000000000000 [ 41.757747] page dumped because: kasan: bad access detected [ 41.763424] [ 41.765024] Memory state around the buggy address: [ 41.769922] ffff8801be714d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 41.777251] ffff8801be714e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 41.784580] >ffff8801be714e80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 41.791908] ^ [ 41.798628] ffff8801be714f00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 41.805958] ffff8801be714f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 41.813285] ================================================================== [ 41.820612] Disabling lock debugging due to kernel taint [ 41.826272] Kernel panic - not syncing: panic_on_warn set ... [ 41.826272] [ 41.833616] CPU: 0 PID: 4452 Comm: syzkaller460196 Tainted: G B 4.16.0-rc2+ #234 [ 41.842335] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 41.851660] Call Trace: [ 41.854230] dump_stack+0x194/0x257 [ 41.857829] ? arch_local_irq_restore+0x53/0x53 [ 41.862472] ? kasan_end_report+0x32/0x50 [ 41.866592] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 41.871316] ? vsnprintf+0x1ed/0x1900 [ 41.875093] ? pppol2tp_connect+0x1a80/0x1dd0 [ 41.879559] panic+0x1e4/0x41c [ 41.882735] ? refcount_error_report+0x214/0x214 [ 41.887473] ? add_taint+0x1c/0x50 [ 41.890984] ? add_taint+0x1c/0x50 [ 41.894495] ? pppol2tp_connect+0x1a91/0x1dd0 [ 41.898971] kasan_end_report+0x50/0x50 [ 41.902932] kasan_report+0x148/0x360 [ 41.906705] __asan_report_load8_noabort+0x14/0x20 [ 41.911604] pppol2tp_connect+0x1a91/0x1dd0 [ 41.915904] ? pppol2tp_recv_payload_hook+0x1b0/0x1b0 [ 41.921077] ? selinux_netlbl_socket_connect+0x76/0x1b0 [ 41.926416] ? selinux_socket_connect+0x311/0x730 [ 41.931231] ? lock_downgrade+0x980/0x980 [ 41.935348] ? selinux_socket_setsockopt+0x80/0x80 [ 41.940259] ? lock_release+0xa40/0xa40 [ 41.944207] ? trace_event_raw_event_sched_switch+0x810/0x810 [ 41.950063] ? __check_object_size+0x8b/0x530 [ 41.954529] ? __might_sleep+0x95/0x190 [ 41.958482] ? security_socket_connect+0x89/0xb0 [ 41.963213] SYSC_connect+0x213/0x4a0 [ 41.966985] ? SYSC_bind+0x410/0x410 [ 41.970684] ? __handle_mm_fault+0x3ce0/0x3ce0 [ 41.975236] ? vmacache_find+0x5f/0x280 [ 41.979179] ? vmacache_update+0xfe/0x130 [ 41.983315] ? mm_fault_error+0x2c0/0x2c0 [ 41.987432] ? move_addr_to_kernel+0x60/0x60 [ 41.991811] ? do_raw_spin_trylock+0x190/0x190 [ 41.996364] ? SyS_accept+0x30/0x30 [ 41.999961] SyS_connect+0x24/0x30 [ 42.003473] do_syscall_64+0x280/0x940 [ 42.007330] ? __do_page_fault+0xc90/0xc90 [ 42.011536] ? finish_task_switch+0x1c0/0x860 [ 42.016001] ? finish_task_switch+0x181/0x860 [ 42.020466] ? syscall_return_slowpath+0x550/0x550 [ 42.025366] ? syscall_return_slowpath+0x2ac/0x550 [ 42.030266] ? prepare_exit_to_usermode+0x350/0x350 [ 42.035255] ? retint_user+0x18/0x18 [ 42.038942] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 42.043772] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 42.048931] RIP: 0033:0x4468f9 [ 42.052093] RSP: 002b:00007fa3c88f8db8 EFLAGS: 00000246 ORIG_RAX: 000000000000002a [ 42.059772] RAX: ffffffffffffffda RBX: 00000000006e29c4 RCX: 00000000004468f9 [ 42.067011] RDX: 000000000000002e RSI: 0000000020348fd2 RDI: 0000000000000004 [ 42.074261] RBP: 00000000006e29c0 R08: 0000000000000000 R09: 0000000000000000 [ 42.081500] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 [ 42.088754] R13: 00007fff15fe827f R14: 00007fa3c88f99c0 R15: 0000000000000003 [ 42.096383] Dumping ftrace buffer: [ 42.099893] (ftrace buffer empty) [ 42.103575] Kernel Offset: disabled [ 42.107177] Rebooting in 86400 seconds..