[....] Starting enhanced syslogd: rsyslogd[ 12.950442] audit: type=1400 audit(1516054381.228:5): avc: denied { syslog } for pid=3514 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: [ 19.525290] audit: type=1400 audit(1516054387.803:6): avc: denied { map } for pid=3654 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 '10.128.15.219' (ECDSA) to the list of known hosts. executing program executing program executing program executing program executing program executing program [ 27.902075] audit: type=1400 audit(1516054396.179:7): avc: denied { map } for pid=3669 comm="syzkaller472056" path="/root/syzkaller472056584" 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 [ 28.001329] l2tp_core: tunl 4: sockfd_lookup(fd=5) returned -9 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 28.358475] l2tp_core: tunl 4: sockfd_lookup(fd=3) returned -9 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 28.579576] l2tp_core: tunl 4: sockfd_lookup(fd=3) returned -9 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 29.240352] l2tp_core: tunl 4: sockfd_lookup(fd=3) returned -9 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 29.681154] l2tp_core: tunl 4: sockfd_lookup(fd=3) returned -9 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 30.193314] ================================================================== [ 30.200728] BUG: KASAN: use-after-free in pppol2tp_connect+0x1a91/0x1dd0 [ 30.207546] Read of size 8 at addr ffff8801c2c402a8 by task syzkaller472056/4457 [ 30.215077] [ 30.216680] CPU: 0 PID: 4457 Comm: syzkaller472056 Not tainted 4.15.0-rc7-next-20180115+ #97 [ 30.225225] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 30.234557] Call Trace: [ 30.237123] dump_stack+0x194/0x257 [ 30.240729] ? arch_local_irq_restore+0x53/0x53 [ 30.245375] ? show_regs_print_info+0x18/0x18 [ 30.249852] ? lock_release+0xa40/0xa40 [ 30.253802] ? pppol2tp_connect+0x1a91/0x1dd0 [ 30.258273] print_address_description+0x73/0x250 [ 30.263105] ? pppol2tp_connect+0x1a91/0x1dd0 [ 30.267578] kasan_report+0x23b/0x360 [ 30.271360] __asan_report_load8_noabort+0x14/0x20 [ 30.276271] pppol2tp_connect+0x1a91/0x1dd0 [ 30.280588] ? pppol2tp_recv_payload_hook+0x1b0/0x1b0 [ 30.285757] ? selinux_netlbl_socket_connect+0x76/0x1b0 [ 30.291098] ? selinux_socket_connect+0x311/0x730 [ 30.295914] ? lock_downgrade+0x980/0x980 [ 30.300040] ? selinux_socket_setsockopt+0x80/0x80 [ 30.304946] ? lock_release+0xa40/0xa40 [ 30.308895] ? trace_event_raw_event_sched_switch+0x800/0x800 [ 30.314756] ? __check_object_size+0x8b/0x530 [ 30.319232] ? handle_mm_fault+0x476/0x930 [ 30.323455] ? __might_sleep+0x95/0x190 [ 30.327422] ? security_socket_connect+0x89/0xb0 [ 30.332162] SYSC_connect+0x213/0x4a0 [ 30.335940] ? SYSC_bind+0x410/0x410 [ 30.339632] ? do_page_fault+0xee/0x720 [ 30.343580] ? __do_page_fault+0xc90/0xc90 [ 30.347809] ? do_futex+0x22a0/0x22a0 [ 30.351607] ? SyS_socket+0x12d/0x1d0 [ 30.355390] ? entry_SYSCALL_64_fastpath+0x5/0xa0 [ 30.360210] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 30.365207] SyS_connect+0x24/0x30 [ 30.368734] entry_SYSCALL_64_fastpath+0x29/0xa0 [ 30.373463] RIP: 0033:0x445c69 [ 30.376627] RSP: 002b:00007f200cbabdb8 EFLAGS: 00000297 ORIG_RAX: 000000000000002a [ 30.384315] RAX: ffffffffffffffda RBX: 00000000006dbc24 RCX: 0000000000445c69 [ 30.391558] RDX: 000000000000002e RSI: 00000000205fafd2 RDI: 0000000000000005 [ 30.398811] RBP: 00000000006dbc20 R08: 0000000000000000 R09: 0000000000000000 [ 30.406058] R10: 0000000000000000 R11: 0000000000000297 R12: 0000000000000000 [ 30.413302] R13: 00007ffc2560dabf R14: 00007f200cbac9c0 R15: 0000000000000005 [ 30.420568] [ 30.422171] Allocated by task 4454: [ 30.425778] save_stack+0x43/0xd0 [ 30.429205] kasan_kmalloc+0xad/0xe0 [ 30.432898] kasan_slab_alloc+0x12/0x20 [ 30.436845] kmem_cache_alloc+0x12e/0x760 [ 30.440966] sk_prot_alloc+0x65/0x2a0 [ 30.444737] sk_alloc+0x105/0x1440 [ 30.448273] inet6_create+0x44d/0x10f0 [ 30.452134] __sock_create+0x4d4/0x850 [ 30.455998] SyS_socket+0xeb/0x1d0 [ 30.459516] entry_SYSCALL_64_fastpath+0x29/0xa0 [ 30.464240] [ 30.465841] Freed by task 4457: [ 30.469095] save_stack+0x43/0xd0 [ 30.472521] __kasan_slab_free+0x11a/0x170 [ 30.476729] kasan_slab_free+0xe/0x10 [ 30.480503] kmem_cache_free+0x86/0x2b0 [ 30.484455] __sk_destruct+0x622/0x910 [ 30.488314] sk_destruct+0x47/0x80 [ 30.491823] __sk_free+0xf1/0x2b0 [ 30.495247] sk_free+0x2a/0x40 [ 30.498413] l2tp_session_free+0x21c/0x2b0 [ 30.502619] pppol2tp_session_destruct+0xd4/0x110 [ 30.507433] __sk_destruct+0xfd/0x910 [ 30.511207] sk_destruct+0x47/0x80 [ 30.514719] __sk_free+0xf1/0x2b0 [ 30.518143] sk_free+0x2a/0x40 [ 30.521308] pppol2tp_put_sk+0x49/0x60 [ 30.525178] rcu_process_callbacks+0xd6c/0x17f0 [ 30.529830] __do_softirq+0x2d7/0xb85 [ 30.533605] [ 30.535213] The buggy address belongs to the object at ffff8801c2c40080 [ 30.535213] which belongs to the cache UDPv6 of size 1664 [ 30.547410] The buggy address is located 552 bytes inside of [ 30.547410] 1664-byte region [ffff8801c2c40080, ffff8801c2c40700) [ 30.559344] The buggy address belongs to the page: [ 30.564249] page:ffffea00070b1000 count:1 mapcount:0 mapping:ffff8801c2c40080 index:0x0 [ 30.572362] flags: 0x2fffc0000000100(slab) [ 30.576569] raw: 02fffc0000000100 ffff8801c2c40080 0000000000000000 0000000100000002 [ 30.584435] raw: ffffea0007624fe0 ffffea000760c820 ffff8801d3379840 0000000000000000 [ 30.592292] page dumped because: kasan: bad access detected [ 30.597972] [ 30.599570] Memory state around the buggy address: [ 30.604470] ffff8801c2c40180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 30.611801] ffff8801c2c40200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 30.619136] >ffff8801c2c40280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 30.626466] ^ [ 30.631112] ffff8801c2c40300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 30.638450] ffff8801c2c40380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 30.645778] ================================================================== [ 30.653117] Disabling lock debugging due to kernel taint [ 30.658596] Kernel panic - not syncing: panic_on_warn set ... [ 30.658596] [ 30.665951] CPU: 0 PID: 4457 Comm: syzkaller472056 Tainted: G B 4.15.0-rc7-next-20180115+ #97 [ 30.675809] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 30.685141] Call Trace: [ 30.687709] dump_stack+0x194/0x257 [ 30.691309] ? arch_local_irq_restore+0x53/0x53 [ 30.695954] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 30.700686] ? vsnprintf+0x1ed/0x1900 [ 30.704462] ? pppol2tp_connect+0x19e0/0x1dd0 [ 30.708940] panic+0x1e4/0x41c [ 30.712122] ? refcount_error_report+0x214/0x214 [ 30.716850] ? add_taint+0x1c/0x50 [ 30.720366] ? add_taint+0x1c/0x50 [ 30.723880] ? pppol2tp_connect+0x1a91/0x1dd0 [ 30.728357] kasan_end_report+0x50/0x50 [ 30.732306] kasan_report+0x148/0x360 [ 30.736088] __asan_report_load8_noabort+0x14/0x20 [ 30.741006] pppol2tp_connect+0x1a91/0x1dd0 [ 30.745329] ? pppol2tp_recv_payload_hook+0x1b0/0x1b0 [ 30.750498] ? selinux_netlbl_socket_connect+0x76/0x1b0 [ 30.755836] ? selinux_socket_connect+0x311/0x730 [ 30.760653] ? lock_downgrade+0x980/0x980 [ 30.764775] ? selinux_socket_setsockopt+0x80/0x80 [ 30.769679] ? lock_release+0xa40/0xa40 [ 30.773632] ? trace_event_raw_event_sched_switch+0x800/0x800 [ 30.779498] ? __check_object_size+0x8b/0x530 [ 30.783971] ? handle_mm_fault+0x476/0x930 [ 30.788183] ? __might_sleep+0x95/0x190 [ 30.792136] ? security_socket_connect+0x89/0xb0 [ 30.796871] SYSC_connect+0x213/0x4a0 [ 30.800646] ? SYSC_bind+0x410/0x410 [ 30.804335] ? do_page_fault+0xee/0x720 [ 30.808284] ? __do_page_fault+0xc90/0xc90 [ 30.812497] ? do_futex+0x22a0/0x22a0 [ 30.816275] ? SyS_socket+0x12d/0x1d0 [ 30.820049] ? entry_SYSCALL_64_fastpath+0x5/0xa0 [ 30.824866] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 30.829860] SyS_connect+0x24/0x30 [ 30.833375] entry_SYSCALL_64_fastpath+0x29/0xa0 [ 30.838107] RIP: 0033:0x445c69 [ 30.841272] RSP: 002b:00007f200cbabdb8 EFLAGS: 00000297 ORIG_RAX: 000000000000002a [ 30.848949] RAX: ffffffffffffffda RBX: 00000000006dbc24 RCX: 0000000000445c69 [ 30.856191] RDX: 000000000000002e RSI: 00000000205fafd2 RDI: 0000000000000005 [ 30.863436] RBP: 00000000006dbc20 R08: 0000000000000000 R09: 0000000000000000 [ 30.870678] R10: 0000000000000000 R11: 0000000000000297 R12: 0000000000000000 [ 30.877925] R13: 00007ffc2560dabf R14: 00007f200cbac9c0 R15: 0000000000000005 [ 30.885681] Dumping ftrace buffer: [ 30.889201] (ftrace buffer empty) [ 30.892881] Kernel Offset: disabled [ 30.896489] Rebooting in 86400 seconds..