[....] Starting enhanced syslogd: rsyslogd[ 13.017152] audit: type=1400 audit(1516329737.854:5): avc: denied { syslog } for pid=3494 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 mcstransd: [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] 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: [ 19.269072] audit: type=1400 audit(1516329744.105:6): avc: denied { map } for pid=3634 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. [ 25.508437] audit: type=1400 audit(1516329750.345:7): avc: denied { map } for pid=3648 comm="syzkaller292102" path="/root/syzkaller292102839" 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 net.ipv6.conf.syz0.accept_dad = 0 net.ipv6.conf.syz0.router_solicitations = 0 RTNETLINK answers: Operation not supported RTNETLINK answers: No buffer space available RTNETLINK answers: Operation not supported RTNETLINK answers: Operation not supported [ 25.879418] IPv6: ADDRCONF(NETDEV_UP): bridge0: link is not ready RTNETLINK answers: Operation not supported RTNETLINK answers: Operation not supported RTNETLINK answers: Invalid argument RTNETLINK answers: Invalid argument RTNETLINK answers: Invalid argument executing program [ 26.210484] ================================================================== [ 26.217891] BUG: KASAN: use-after-free in ip6_xmit+0x2048/0x2090 [ 26.224008] Read of size 8 at addr ffff8801d8b4ce98 by task syzkaller292102/3649 [ 26.231510] [ 26.233116] CPU: 1 PID: 3649 Comm: syzkaller292102 Not tainted 4.15.0-rc8+ #268 [ 26.240534] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 26.249861] Call Trace: [ 26.252424] dump_stack+0x194/0x257 [ 26.256027] ? arch_local_irq_restore+0x53/0x53 [ 26.260681] ? show_regs_print_info+0x18/0x18 [ 26.265166] ? ip6_xmit+0x2048/0x2090 [ 26.268943] print_address_description+0x73/0x250 [ 26.273763] ? ip6_xmit+0x2048/0x2090 [ 26.277539] kasan_report+0x25b/0x340 [ 26.281316] __asan_report_load8_noabort+0x14/0x20 [ 26.286220] ip6_xmit+0x2048/0x2090 [ 26.289834] ? ip6_finish_output2+0x23a0/0x23a0 [ 26.294479] ? fl6_update_dst+0x127/0x2b0 [ 26.298603] ? check_noncircular+0x20/0x20 [ 26.302811] ? inet6_csk_route_socket+0x691/0xe80 [ 26.307631] ? lock_acquire+0x1d5/0x580 [ 26.311577] ? lock_acquire+0x1d5/0x580 [ 26.315523] ? inet6_csk_xmit+0x114/0x580 [ 26.319651] ? lock_release+0xa40/0xa40 [ 26.323613] inet6_csk_xmit+0x2fc/0x580 [ 26.327564] ? inet6_csk_update_pmtu+0x160/0x160 [ 26.332295] ? __sk_dst_check+0x1a5/0x380 [ 26.336417] ? sk_wait_data+0x610/0x610 [ 26.340383] l2tp_xmit_skb+0x1068/0x1410 [ 26.344427] ? l2tp_session_create+0xc60/0xc60 [ 26.348982] ? sock_wmalloc+0x15d/0x1d0 [ 26.352929] ? iov_iter_advance+0x13f0/0x13f0 [ 26.357398] ? pppol2tp_sendmsg+0x41b/0x670 [ 26.361697] pppol2tp_sendmsg+0x470/0x670 [ 26.365822] ? selinux_socket_sendmsg+0x36/0x40 [ 26.370476] ? pppol2tp_session_ioctl+0xa90/0xa90 [ 26.375297] sock_sendmsg+0xca/0x110 [ 26.378985] ___sys_sendmsg+0x767/0x8b0 [ 26.382938] ? copy_msghdr_from_user+0x590/0x590 [ 26.387678] ? __do_page_fault+0x5f7/0xc90 [ 26.391890] ? lock_downgrade+0x980/0x980 [ 26.396033] ? __fget_light+0x297/0x380 [ 26.399983] ? fget_raw+0x20/0x20 [ 26.403413] ? __handle_mm_fault+0x3ce0/0x3ce0 [ 26.408161] ? vmacache_find+0x5f/0x280 [ 26.412119] ? up_read+0x1a/0x40 [ 26.415462] ? __do_page_fault+0x3d6/0xc90 [ 26.419680] ? __fdget+0x18/0x20 [ 26.423025] __sys_sendmsg+0xe5/0x210 [ 26.426797] ? __sys_sendmsg+0xe5/0x210 [ 26.430748] ? SyS_shutdown+0x290/0x290 [ 26.434701] ? __do_page_fault+0xc90/0xc90 [ 26.438927] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 26.443925] SyS_sendmsg+0x2d/0x50 [ 26.447442] entry_SYSCALL_64_fastpath+0x29/0xa0 [ 26.452170] RIP: 0033:0x4465b9 [ 26.455598] RSP: 002b:00007ffeeb9730c8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e [ 26.463627] RAX: ffffffffffffffda RBX: 0000000000000068 RCX: 00000000004465b9 [ 26.470884] RDX: 0000000000000081 RSI: 000000002037ffc8 RDI: 0000000000000005 [ 26.478128] RBP: 00000000004a8718 R08: 00000000004a8718 R09: 00000000004a8718 [ 26.485370] R10: 00000000004a8718 R11: 0000000000000246 R12: 00000000004036f0 [ 26.492615] R13: 0000000000403780 R14: 0000000000000000 R15: 0000000000000000 [ 26.499873] [ 26.501474] Allocated by task 3649: [ 26.505078] save_stack+0x43/0xd0 [ 26.508502] kasan_kmalloc+0xad/0xe0 [ 26.512187] kasan_slab_alloc+0x12/0x20 [ 26.516133] kmem_cache_alloc+0x12e/0x760 [ 26.520251] dst_alloc+0x11f/0x1a0 [ 26.523764] rt_dst_alloc+0xe9/0x540 [ 26.527449] ip_route_output_key_hash_rcu+0xa40/0x2c40 [ 26.532697] ip_route_output_key_hash+0x20b/0x370 [ 26.537512] __ip4_datagram_connect+0xa6d/0x1240 [ 26.542238] __ip6_datagram_connect+0xbaf/0xf90 [ 26.546877] ip6_datagram_connect+0x2f/0x50 [ 26.551169] inet_dgram_connect+0x16b/0x1f0 [ 26.555467] SYSC_connect+0x213/0x4a0 [ 26.559240] SyS_connect+0x24/0x30 [ 26.562765] entry_SYSCALL_64_fastpath+0x29/0xa0 [ 26.567488] [ 26.569088] Freed by task 3649: [ 26.572339] save_stack+0x43/0xd0 [ 26.575937] kasan_slab_free+0x71/0xc0 [ 26.579799] kmem_cache_free+0x83/0x2a0 [ 26.584269] dst_destroy+0x216/0x330 [ 26.587953] dst_destroy_rcu+0x16/0x20 [ 26.591815] rcu_process_callbacks+0xd6c/0x17f0 [ 26.596454] __do_softirq+0x2d7/0xb85 [ 26.600224] [ 26.601824] The buggy address belongs to the object at ffff8801d8b4ce80 [ 26.601824] which belongs to the cache ip_dst_cache of size 216 [ 26.614538] The buggy address is located 24 bytes inside of [ 26.614538] 216-byte region [ffff8801d8b4ce80, ffff8801d8b4cf58) [ 26.626292] The buggy address belongs to the page: [ 26.631456] page:ffffea000762d300 count:1 mapcount:0 mapping:ffff8801d8b4c0c0 index:0x0 [ 26.639572] flags: 0x2fffc0000000100(slab) [ 26.643789] raw: 02fffc0000000100 ffff8801d8b4c0c0 0000000000000000 000000010000000c [ 26.651642] raw: ffffea0006f1bba0 ffff8801d6f77748 ffff8801d6f7c980 0000000000000000 [ 26.659490] page dumped because: kasan: bad access detected [ 26.665175] [ 26.666776] Memory state around the buggy address: [ 26.671679] ffff8801d8b4cd80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 26.679010] ffff8801d8b4ce00: 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc [ 26.686342] >ffff8801d8b4ce80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 26.693673] ^ [ 26.697790] ffff8801d8b4cf00: fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc fc [ 26.705124] ffff8801d8b4cf80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 26.712462] ================================================================== [ 26.719801] Disabling lock debugging due to kernel taint [ 26.725263] Kernel panic - not syncing: panic_on_warn set ... [ 26.725263] [ 26.732613] CPU: 1 PID: 3649 Comm: syzkaller292102 Tainted: G B 4.15.0-rc8+ #268 [ 26.741332] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 26.750661] Call Trace: [ 26.753225] dump_stack+0x194/0x257 [ 26.756824] ? arch_local_irq_restore+0x53/0x53 [ 26.762333] ? kasan_end_report+0x32/0x50 [ 26.766454] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 26.771184] ? vsnprintf+0x1ed/0x1900 [ 26.774957] ? ip6_xmit+0x1f60/0x2090 [ 26.778742] panic+0x1e4/0x41c [ 26.781907] ? refcount_error_report+0x214/0x214 [ 26.786636] ? add_taint+0x1c/0x50 [ 26.790149] ? add_taint+0x1c/0x50 [ 26.793663] ? ip6_xmit+0x2048/0x2090 [ 26.797436] kasan_end_report+0x50/0x50 [ 26.801395] kasan_report+0x144/0x340 [ 26.805171] __asan_report_load8_noabort+0x14/0x20 [ 26.810071] ip6_xmit+0x2048/0x2090 [ 26.813675] ? ip6_finish_output2+0x23a0/0x23a0 [ 26.818317] ? fl6_update_dst+0x127/0x2b0 [ 26.822438] ? check_noncircular+0x20/0x20 [ 26.827327] ? inet6_csk_route_socket+0x691/0xe80 [ 26.832147] ? lock_acquire+0x1d5/0x580 [ 26.836094] ? lock_acquire+0x1d5/0x580 [ 26.840039] ? inet6_csk_xmit+0x114/0x580 [ 26.844163] ? lock_release+0xa40/0xa40 [ 26.848117] inet6_csk_xmit+0x2fc/0x580 [ 26.852065] ? inet6_csk_update_pmtu+0x160/0x160 [ 26.856793] ? __sk_dst_check+0x1a5/0x380 [ 26.860911] ? sk_wait_data+0x610/0x610 [ 26.864863] l2tp_xmit_skb+0x1068/0x1410 [ 26.868901] ? l2tp_session_create+0xc60/0xc60 [ 26.873455] ? sock_wmalloc+0x15d/0x1d0 [ 26.877401] ? iov_iter_advance+0x13f0/0x13f0 [ 26.881869] ? pppol2tp_sendmsg+0x41b/0x670 [ 26.886164] pppol2tp_sendmsg+0x470/0x670 [ 26.890293] ? selinux_socket_sendmsg+0x36/0x40 [ 26.894933] ? pppol2tp_session_ioctl+0xa90/0xa90 [ 26.899747] sock_sendmsg+0xca/0x110 [ 26.903433] ___sys_sendmsg+0x767/0x8b0 [ 26.907391] ? copy_msghdr_from_user+0x590/0x590 [ 26.912126] ? __do_page_fault+0x5f7/0xc90 [ 26.916422] ? lock_downgrade+0x980/0x980 [ 26.920543] ? __fget_light+0x297/0x380 [ 26.924497] ? fget_raw+0x20/0x20 [ 26.927923] ? __handle_mm_fault+0x3ce0/0x3ce0 [ 26.932477] ? vmacache_find+0x5f/0x280 [ 26.936428] ? up_read+0x1a/0x40 [ 26.939777] ? __do_page_fault+0x3d6/0xc90 [ 26.943983] ? __fdget+0x18/0x20 [ 26.947414] __sys_sendmsg+0xe5/0x210 [ 26.951187] ? __sys_sendmsg+0xe5/0x210 [ 26.955482] ? SyS_shutdown+0x290/0x290 [ 26.960565] ? __do_page_fault+0xc90/0xc90 [ 26.964779] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 26.969769] SyS_sendmsg+0x2d/0x50 [ 26.973286] entry_SYSCALL_64_fastpath+0x29/0xa0 [ 26.978013] RIP: 0033:0x4465b9 [ 26.981357] RSP: 002b:00007ffeeb9730c8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e [ 26.989038] RAX: ffffffffffffffda RBX: 0000000000000068 RCX: 00000000004465b9 [ 26.996281] RDX: 0000000000000081 RSI: 000000002037ffc8 RDI: 0000000000000005 [ 27.003540] RBP: 00000000004a8718 R08: 00000000004a8718 R09: 00000000004a8718 [ 27.010781] R10: 00000000004a8718 R11: 0000000000000246 R12: 00000000004036f0 [ 27.018025] R13: 0000000000403780 R14: 0000000000000000 R15: 0000000000000000 [ 27.026012] Dumping ftrace buffer: [ 27.029524] (ftrace buffer empty) [ 27.033208] Kernel Offset: disabled [ 27.036820] Rebooting in 86400 seconds..