[....] Starting enhanced syslogd: rsyslogd[ 15.072188] audit: type=1400 audit(1518425518.831:5): avc: denied { syslog } for pid=3930 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: [ 18.371566] audit: type=1400 audit(1518425522.131:6): avc: denied { map } for pid=4069 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 '10.128.15.201' (ECDSA) to the list of known hosts. executing program executing program executing program executing program executing program executing program [ 40.764049] audit: type=1400 audit(1518425544.523:7): avc: denied { map } for pid=4087 comm="syzkaller502096" path="/root/syzkaller502096553" 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 [ 40.770713] 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 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 41.980221] ================================================================== [ 41.987705] BUG: KASAN: use-after-free in pppol2tp_connect+0x1a91/0x1dd0 [ 41.994517] Read of size 8 at addr ffff8801c0317928 by task syzkaller502096/4322 [ 42.002017] [ 42.003621] CPU: 1 PID: 4322 Comm: syzkaller502096 Not tainted 4.16.0-rc1+ #309 [ 42.011036] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 42.020360] Call Trace: [ 42.022924] dump_stack+0x194/0x257 [ 42.026527] ? arch_local_irq_restore+0x53/0x53 [ 42.031170] ? show_regs_print_info+0x18/0x18 [ 42.035643] ? lock_release+0xa40/0xa40 [ 42.039679] ? pppol2tp_connect+0x1a91/0x1dd0 [ 42.044147] print_address_description+0x73/0x250 [ 42.048962] ? pppol2tp_connect+0x1a91/0x1dd0 [ 42.053428] kasan_report+0x23b/0x360 [ 42.057202] __asan_report_load8_noabort+0x14/0x20 [ 42.062104] pppol2tp_connect+0x1a91/0x1dd0 [ 42.066404] ? pppol2tp_recv_payload_hook+0x1b0/0x1b0 [ 42.071570] ? selinux_netlbl_socket_connect+0x76/0x1b0 [ 42.076921] ? selinux_socket_connect+0x311/0x730 [ 42.081734] ? lock_downgrade+0x980/0x980 [ 42.085858] ? selinux_socket_setsockopt+0x80/0x80 [ 42.090757] ? lock_release+0xa40/0xa40 [ 42.094704] ? trace_event_raw_event_sched_switch+0x810/0x810 [ 42.100558] ? __check_object_size+0x8b/0x530 [ 42.105030] ? __might_sleep+0x95/0x190 [ 42.108991] ? security_socket_connect+0x89/0xb0 [ 42.113726] SYSC_connect+0x213/0x4a0 [ 42.117500] ? SYSC_bind+0x410/0x410 [ 42.121188] ? __handle_mm_fault+0x3ce0/0x3ce0 [ 42.125741] ? vmacache_find+0x5f/0x280 [ 42.129706] ? mm_fault_error+0x2c0/0x2c0 [ 42.133832] ? move_addr_to_kernel+0x60/0x60 [ 42.138217] SyS_connect+0x24/0x30 [ 42.141730] ? SyS_accept+0x30/0x30 [ 42.145343] do_syscall_64+0x282/0x940 [ 42.149217] ? __do_page_fault+0xc90/0xc90 [ 42.153429] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 42.158160] ? syscall_return_slowpath+0x550/0x550 [ 42.163065] ? syscall_return_slowpath+0x2ac/0x550 [ 42.167966] ? prepare_exit_to_usermode+0x350/0x350 [ 42.172958] ? retint_user+0x18/0x18 [ 42.176648] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 42.181471] entry_SYSCALL_64_after_hwframe+0x26/0x9b [ 42.186638] RIP: 0033:0x441c69 [ 42.189801] RSP: 002b:00007ffc47d38848 EFLAGS: 00000246 ORIG_RAX: 000000000000002a [ 42.197482] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000441c69 [ 42.204726] RDX: 000000000000002e RSI: 00000000205fafd2 RDI: 0000000000000004 [ 42.211968] RBP: 0000000000000000 R08: 00000000000000ea R09: 00000000000000ea [ 42.219210] R10: 00000000000000ea R11: 0000000000000246 R12: 000000000000a3f7 [ 42.226451] R13: 0000000000403120 R14: 0000000000000000 R15: 0000000000000000 [ 42.233708] [ 42.235310] Allocated by task 4320: [ 42.238912] save_stack+0x43/0xd0 [ 42.242333] kasan_kmalloc+0xad/0xe0 [ 42.246017] kasan_slab_alloc+0x12/0x20 [ 42.249961] kmem_cache_alloc+0x12e/0x760 [ 42.254081] sk_prot_alloc+0x65/0x2a0 [ 42.257855] sk_alloc+0x105/0x1440 [ 42.261369] inet6_create+0x44d/0x10f0 [ 42.265229] __sock_create+0x4d4/0x850 [ 42.269088] SyS_socket+0xeb/0x1d0 [ 42.272598] do_syscall_64+0x282/0x940 [ 42.276456] entry_SYSCALL_64_after_hwframe+0x26/0x9b [ 42.281612] [ 42.283210] Freed by task 4322: [ 42.286458] save_stack+0x43/0xd0 [ 42.289881] __kasan_slab_free+0x11a/0x170 [ 42.294091] kasan_slab_free+0xe/0x10 [ 42.297860] kmem_cache_free+0x83/0x2a0 [ 42.301805] __sk_destruct+0x628/0x920 [ 42.305669] rcu_process_callbacks+0xd6c/0x17f0 [ 42.310309] __do_softirq+0x2d7/0xb85 [ 42.314078] [ 42.315680] The buggy address belongs to the object at ffff8801c0317700 [ 42.315680] which belongs to the cache UDPv6 of size 1664 [ 42.327875] The buggy address is located 552 bytes inside of [ 42.327875] 1664-byte region [ffff8801c0317700, ffff8801c0317d80) [ 42.339807] The buggy address belongs to the page: [ 42.344708] page:ffffea000700c5c0 count:1 mapcount:0 mapping:ffff8801c0317000 index:0x0 [ 42.352822] flags: 0x2fffc0000000100(slab) [ 42.357031] raw: 02fffc0000000100 ffff8801c0317000 0000000000000000 0000000100000002 [ 42.364892] raw: ffffea0006ff4220 ffffea0006fed6e0 ffff8801d27796c0 0000000000000000 [ 42.372743] page dumped because: kasan: bad access detected [ 42.378420] [ 42.380019] Memory state around the buggy address: [ 42.384917] ffff8801c0317800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 42.392248] ffff8801c0317880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 42.399575] >ffff8801c0317900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 42.406907] ^ [ 42.411547] ffff8801c0317980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 42.418877] ffff8801c0317a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 42.426204] ================================================================== [ 42.433533] Disabling lock debugging due to kernel taint [ 42.439017] Kernel panic - not syncing: panic_on_warn set ... [ 42.439017] [ 42.446353] CPU: 1 PID: 4322 Comm: syzkaller502096 Tainted: G B 4.16.0-rc1+ #309 [ 42.455073] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 42.464396] Call Trace: [ 42.466956] dump_stack+0x194/0x257 [ 42.470555] ? arch_local_irq_restore+0x53/0x53 [ 42.475194] ? kasan_end_report+0x32/0x50 [ 42.479313] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 42.484039] ? vsnprintf+0x1ed/0x1900 [ 42.487823] ? pppol2tp_connect+0x19b0/0x1dd0 [ 42.492290] panic+0x1e4/0x41c [ 42.495451] ? refcount_error_report+0x214/0x214 [ 42.500176] ? add_taint+0x1c/0x50 [ 42.503692] ? add_taint+0x1c/0x50 [ 42.507203] ? pppol2tp_connect+0x1a91/0x1dd0 [ 42.511667] kasan_end_report+0x50/0x50 [ 42.515610] kasan_report+0x148/0x360 [ 42.519380] __asan_report_load8_noabort+0x14/0x20 [ 42.524278] pppol2tp_connect+0x1a91/0x1dd0 [ 42.528572] ? pppol2tp_recv_payload_hook+0x1b0/0x1b0 [ 42.533735] ? selinux_netlbl_socket_connect+0x76/0x1b0 [ 42.539071] ? selinux_socket_connect+0x311/0x730 [ 42.543894] ? lock_downgrade+0x980/0x980 [ 42.548013] ? selinux_socket_setsockopt+0x80/0x80 [ 42.552913] ? lock_release+0xa40/0xa40 [ 42.556857] ? trace_event_raw_event_sched_switch+0x810/0x810 [ 42.562714] ? __check_object_size+0x8b/0x530 [ 42.567183] ? __might_sleep+0x95/0x190 [ 42.571134] ? security_socket_connect+0x89/0xb0 [ 42.575862] SYSC_connect+0x213/0x4a0 [ 42.579633] ? SYSC_bind+0x410/0x410 [ 42.583318] ? __handle_mm_fault+0x3ce0/0x3ce0 [ 42.587871] ? vmacache_find+0x5f/0x280 [ 42.591827] ? mm_fault_error+0x2c0/0x2c0 [ 42.595944] ? move_addr_to_kernel+0x60/0x60 [ 42.600324] SyS_connect+0x24/0x30 [ 42.603836] ? SyS_accept+0x30/0x30 [ 42.607436] do_syscall_64+0x282/0x940 [ 42.611294] ? __do_page_fault+0xc90/0xc90 [ 42.615502] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 42.620229] ? syscall_return_slowpath+0x550/0x550 [ 42.625132] ? syscall_return_slowpath+0x2ac/0x550 [ 42.630033] ? prepare_exit_to_usermode+0x350/0x350 [ 42.635019] ? retint_user+0x18/0x18 [ 42.638705] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 42.644084] entry_SYSCALL_64_after_hwframe+0x26/0x9b [ 42.649246] RIP: 0033:0x441c69 [ 42.652405] RSP: 002b:00007ffc47d38848 EFLAGS: 00000246 ORIG_RAX: 000000000000002a [ 42.660083] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000441c69 [ 42.667324] RDX: 000000000000002e RSI: 00000000205fafd2 RDI: 0000000000000004 [ 42.674563] RBP: 0000000000000000 R08: 00000000000000ea R09: 00000000000000ea [ 42.681804] R10: 00000000000000ea R11: 0000000000000246 R12: 000000000000a3f7 [ 42.689046] R13: 0000000000403120 R14: 0000000000000000 R15: 0000000000000000 [ 42.696701] Dumping ftrace buffer: [ 42.700215] (ftrace buffer empty) [ 42.703905] Kernel Offset: disabled [ 42.707509] Rebooting in 86400 seconds..