[....] Starting enhanced syslogd: rsyslogd[ 16.568727] audit: type=1400 audit(1520994321.096:5): avc: denied { syslog } for pid=3989 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: [ 19.425495] audit: type=1400 audit(1520994323.953:6): avc: denied { map } for pid=4128 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 '10.128.10.6' (ECDSA) to the list of known hosts. executing program [ 25.829996] audit: type=1400 audit(1520994330.357:7): avc: denied { map } for pid=4142 comm="syzkaller031854" path="/root/syzkaller031854160" 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 [ 25.835591] ================================================================== [ 25.863356] BUG: KASAN: use-after-free in ip6_xmit+0x1f76/0x2260 [ 25.869479] Read of size 8 at addr ffff8801d739be18 by task syzkaller031854/4142 [ 25.876986] [ 25.878594] CPU: 0 PID: 4142 Comm: syzkaller031854 Not tainted 4.16.0-rc4+ #264 [ 25.886010] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 25.895337] Call Trace: [ 25.897906] dump_stack+0x194/0x24d [ 25.901514] ? arch_local_irq_restore+0x53/0x53 [ 25.906159] ? show_regs_print_info+0x18/0x18 [ 25.910638] ? ip6_xmit+0x1f76/0x2260 [ 25.914415] print_address_description+0x73/0x250 [ 25.919235] ? ip6_xmit+0x1f76/0x2260 [ 25.923009] kasan_report+0x23c/0x360 [ 25.926797] __asan_report_load8_noabort+0x14/0x20 [ 25.931701] ip6_xmit+0x1f76/0x2260 [ 25.935319] ? ip6_finish_output2+0x23d0/0x23d0 [ 25.939964] ? fl6_update_dst+0x127/0x2b0 [ 25.944101] ? inet6_csk_route_socket+0x691/0xe80 [ 25.948923] ? trace_hardirqs_off+0x10/0x10 [ 25.953220] ? lock_acquire+0x1d5/0x580 [ 25.957166] ? lock_acquire+0x1d5/0x580 [ 25.961114] ? inet6_csk_xmit+0x114/0x580 [ 25.965253] ? trace_hardirqs_off+0x10/0x10 [ 25.969551] ? lock_release+0xa40/0xa40 [ 25.973520] inet6_csk_xmit+0x2fc/0x580 [ 25.977472] ? inet6_csk_update_pmtu+0x160/0x160 [ 25.982222] ? __sk_dst_check+0x1a5/0x380 [ 25.986349] ? sock_kzfree_s+0x60/0x60 [ 25.990227] l2tp_xmit_skb+0x105f/0x1410 [ 25.994271] ? l2tp_session_create+0xb80/0xb80 [ 25.998827] ? sock_wmalloc+0x15d/0x1d0 [ 26.002784] ? iov_iter_advance+0x13f0/0x13f0 [ 26.007259] ? pppol2tp_sendmsg+0x41b/0x670 [ 26.011557] pppol2tp_sendmsg+0x470/0x670 [ 26.015685] ? selinux_socket_sendmsg+0x36/0x40 [ 26.020329] ? pppol2tp_getsockopt+0x900/0x900 [ 26.024889] sock_sendmsg+0xca/0x110 [ 26.028582] SYSC_sendto+0x361/0x5c0 [ 26.032277] ? SYSC_connect+0x4a0/0x4a0 [ 26.036234] ? inet_dgram_connect+0x172/0x1f0 [ 26.040709] ? SYSC_connect+0x2e0/0x4a0 [ 26.044690] ? mm_fault_error+0x2c0/0x2c0 [ 26.048813] ? move_addr_to_kernel+0x60/0x60 [ 26.053199] SyS_sendto+0x40/0x50 [ 26.056626] ? SyS_getpeername+0x30/0x30 [ 26.060673] do_syscall_64+0x281/0x940 [ 26.064538] ? __do_page_fault+0xc90/0xc90 [ 26.068748] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 26.073479] ? syscall_return_slowpath+0x550/0x550 [ 26.078398] ? syscall_return_slowpath+0x2ac/0x550 [ 26.083304] ? prepare_exit_to_usermode+0x350/0x350 [ 26.088301] ? entry_SYSCALL_64_after_hwframe+0x52/0xb7 [ 26.093961] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 26.098802] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 26.103964] RIP: 0033:0x4401e9 [ 26.107131] RSP: 002b:00007ffd2f680ea8 EFLAGS: 00000216 ORIG_RAX: 000000000000002c [ 26.114825] RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 00000000004401e9 [ 26.122069] RDX: 0000000000000000 RSI: 0000000020001180 RDI: 0000000000000004 [ 26.129322] RBP: 00000000006ca018 R08: 00000000200021c0 R09: 0000000000000080 [ 26.136569] R10: 0000000000040001 R11: 0000000000000216 R12: 0000000000401b10 [ 26.143820] R13: 0000000000401ba0 R14: 0000000000000000 R15: 0000000000000000 [ 26.151082] [ 26.152684] Allocated by task 3810: [ 26.156288] save_stack+0x43/0xd0 [ 26.159709] kasan_kmalloc+0xad/0xe0 [ 26.163405] kasan_slab_alloc+0x12/0x20 [ 26.167357] kmem_cache_alloc+0x12e/0x760 [ 26.171490] dst_alloc+0x11f/0x1a0 [ 26.175001] rt_dst_alloc+0xe9/0x4e0 [ 26.178687] ip_route_input_slow+0x1284/0x3c80 [ 26.183246] ip_route_input_rcu+0xf1/0xd20 [ 26.187544] ip_route_input_noref+0xf5/0x1e0 [ 26.191924] ip_rcv_finish+0x3a6/0x2040 [ 26.195870] ip_rcv+0xb76/0x1820 [ 26.199213] __netif_receive_skb_core+0x1a41/0x3460 [ 26.204200] __netif_receive_skb+0x2c/0x1b0 [ 26.208501] netif_receive_skb_internal+0x10b/0x670 [ 26.213489] napi_gro_receive+0x3d0/0x500 [ 26.217618] receive_buf+0xb6f/0x2530 [ 26.221406] virtnet_poll+0x320/0xb70 [ 26.225180] net_rx_action+0x792/0x1910 [ 26.229131] __do_softirq+0x2d7/0xb85 [ 26.232902] [ 26.234501] Freed by task 3829: [ 26.237757] save_stack+0x43/0xd0 [ 26.241196] __kasan_slab_free+0x11a/0x170 [ 26.245406] kasan_slab_free+0xe/0x10 [ 26.249180] kmem_cache_free+0x83/0x2a0 [ 26.253127] dst_destroy+0x257/0x370 [ 26.256812] dst_destroy_rcu+0x16/0x20 [ 26.260672] rcu_process_callbacks+0xd6c/0x17f0 [ 26.265312] __do_softirq+0x2d7/0xb85 [ 26.269093] [ 26.270699] The buggy address belongs to the object at ffff8801d739be00 [ 26.270699] which belongs to the cache ip_dst_cache of size 160 [ 26.283411] The buggy address is located 24 bytes inside of [ 26.283411] 160-byte region [ffff8801d739be00, ffff8801d739bea0) [ 26.295172] The buggy address belongs to the page: [ 26.300092] page:ffffea00075ce6c0 count:1 mapcount:0 mapping:ffff8801d739b000 index:0xffff8801d739b000 [ 26.309523] flags: 0x2fffc0000000100(slab) [ 26.313731] raw: 02fffc0000000100 ffff8801d739b000 ffff8801d739b000 000000010000000b [ 26.321592] raw: ffff8801d6bbe338 ffffea00074930e0 ffff8801d5bd5800 0000000000000000 [ 26.329461] page dumped because: kasan: bad access detected [ 26.335147] [ 26.336763] Memory state around the buggy address: [ 26.341665] ffff8801d739bd00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 26.349000] ffff8801d739bd80: 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc [ 26.356332] >ffff8801d739be00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 26.363666] ^ [ 26.367783] ffff8801d739be80: fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc [ 26.375121] ffff8801d739bf00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 26.382449] ================================================================== [ 26.389780] Disabling lock debugging due to kernel taint [ 26.395245] Kernel panic - not syncing: panic_on_warn set ... [ 26.395245] [ 26.402592] CPU: 0 PID: 4142 Comm: syzkaller031854 Tainted: G B 4.16.0-rc4+ #264 [ 26.411335] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 26.420659] Call Trace: [ 26.423226] dump_stack+0x194/0x24d [ 26.426827] ? arch_local_irq_restore+0x53/0x53 [ 26.431474] ? kasan_end_report+0x32/0x50 [ 26.435606] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 26.440332] ? vsnprintf+0x1ed/0x1900 [ 26.444106] ? ip6_xmit+0x1f40/0x2260 [ 26.447879] panic+0x1e4/0x41c [ 26.451040] ? refcount_error_report+0x214/0x214 [ 26.455775] ? add_taint+0x1c/0x50 [ 26.459285] ? add_taint+0x1c/0x50 [ 26.462794] ? ip6_xmit+0x1f76/0x2260 [ 26.466567] kasan_end_report+0x50/0x50 [ 26.470518] kasan_report+0x149/0x360 [ 26.474388] __asan_report_load8_noabort+0x14/0x20 [ 26.479294] ip6_xmit+0x1f76/0x2260 [ 26.482898] ? ip6_finish_output2+0x23d0/0x23d0 [ 26.487539] ? fl6_update_dst+0x127/0x2b0 [ 26.491658] ? inet6_csk_route_socket+0x691/0xe80 [ 26.496474] ? trace_hardirqs_off+0x10/0x10 [ 26.500776] ? lock_acquire+0x1d5/0x580 [ 26.504722] ? lock_acquire+0x1d5/0x580 [ 26.508667] ? inet6_csk_xmit+0x114/0x580 [ 26.512785] ? trace_hardirqs_off+0x10/0x10 [ 26.517079] ? lock_release+0xa40/0xa40 [ 26.521037] inet6_csk_xmit+0x2fc/0x580 [ 26.524985] ? inet6_csk_update_pmtu+0x160/0x160 [ 26.529714] ? __sk_dst_check+0x1a5/0x380 [ 26.533834] ? sock_kzfree_s+0x60/0x60 [ 26.537702] l2tp_xmit_skb+0x105f/0x1410 [ 26.541740] ? l2tp_session_create+0xb80/0xb80 [ 26.546295] ? sock_wmalloc+0x15d/0x1d0 [ 26.550239] ? iov_iter_advance+0x13f0/0x13f0 [ 26.554716] ? pppol2tp_sendmsg+0x41b/0x670 [ 26.559012] pppol2tp_sendmsg+0x470/0x670 [ 26.563141] ? selinux_socket_sendmsg+0x36/0x40 [ 26.567783] ? pppol2tp_getsockopt+0x900/0x900 [ 26.572339] sock_sendmsg+0xca/0x110 [ 26.576032] SYSC_sendto+0x361/0x5c0 [ 26.579732] ? SYSC_connect+0x4a0/0x4a0 [ 26.583697] ? inet_dgram_connect+0x172/0x1f0 [ 26.588176] ? SYSC_connect+0x2e0/0x4a0 [ 26.592138] ? mm_fault_error+0x2c0/0x2c0 [ 26.596257] ? move_addr_to_kernel+0x60/0x60 [ 26.600635] SyS_sendto+0x40/0x50 [ 26.604060] ? SyS_getpeername+0x30/0x30 [ 26.608094] do_syscall_64+0x281/0x940 [ 26.611950] ? __do_page_fault+0xc90/0xc90 [ 26.616156] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 26.620883] ? syscall_return_slowpath+0x550/0x550 [ 26.625792] ? syscall_return_slowpath+0x2ac/0x550 [ 26.630689] ? prepare_exit_to_usermode+0x350/0x350 [ 26.635676] ? entry_SYSCALL_64_after_hwframe+0x52/0xb7 [ 26.641016] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 26.645835] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 26.650993] RIP: 0033:0x4401e9 [ 26.654155] RSP: 002b:00007ffd2f680ea8 EFLAGS: 00000216 ORIG_RAX: 000000000000002c [ 26.661835] RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 00000000004401e9 [ 26.669083] RDX: 0000000000000000 RSI: 0000000020001180 RDI: 0000000000000004 [ 26.676321] RBP: 00000000006ca018 R08: 00000000200021c0 R09: 0000000000000080 [ 26.683562] R10: 0000000000040001 R11: 0000000000000216 R12: 0000000000401b10 [ 26.690804] R13: 0000000000401ba0 R14: 0000000000000000 R15: 0000000000000000 [ 26.698487] Dumping ftrace buffer: [ 26.701998] (ftrace buffer empty) [ 26.705676] Kernel Offset: disabled [ 26.709275] Rebooting in 86400 seconds..