[....] Starting enhanced syslogd: rsyslogd[ 15.862347] audit: type=1400 audit(1520776949.921:5): avc: denied { syslog } for pid=3974 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: [ 17.925645] audit: type=1400 audit(1520776951.984:6): avc: denied { map } for pid=4111 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 '10.128.0.44' (ECDSA) to the list of known hosts. executing program [ 24.215575] audit: type=1400 audit(1520776958.274:7): avc: denied { map } for pid=4125 comm="syzkaller307432" path="/root/syzkaller307432726" 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 [ 24.220455] ================================================================== [ 24.248853] BUG: KASAN: use-after-free in ip6_xmit+0x1f76/0x2260 [ 24.254972] Read of size 8 at addr ffff8801d6d87f18 by task syzkaller307432/4125 [ 24.262480] [ 24.264086] CPU: 0 PID: 4125 Comm: syzkaller307432 Not tainted 4.16.0-rc4+ #260 [ 24.271503] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 24.280827] Call Trace: [ 24.283389] dump_stack+0x194/0x24d [ 24.286990] ? arch_local_irq_restore+0x53/0x53 [ 24.291632] ? show_regs_print_info+0x18/0x18 [ 24.296111] ? ip6_xmit+0x1f76/0x2260 [ 24.299888] print_address_description+0x73/0x250 [ 24.304702] ? ip6_xmit+0x1f76/0x2260 [ 24.308479] kasan_report+0x23c/0x360 [ 24.312258] __asan_report_load8_noabort+0x14/0x20 [ 24.317159] ip6_xmit+0x1f76/0x2260 [ 24.320771] ? ip6_finish_output2+0x23d0/0x23d0 [ 24.325414] ? fl6_update_dst+0x127/0x2b0 [ 24.329537] ? inet6_csk_route_socket+0x691/0xe80 [ 24.334355] ? trace_hardirqs_off+0x10/0x10 [ 24.338648] ? lock_acquire+0x1d5/0x580 [ 24.342592] ? lock_acquire+0x1d5/0x580 [ 24.346539] ? inet6_csk_xmit+0x114/0x580 [ 24.350658] ? trace_hardirqs_off+0x10/0x10 [ 24.354961] ? lock_release+0xa40/0xa40 [ 24.358926] inet6_csk_xmit+0x2fc/0x580 [ 24.362876] ? inet6_csk_update_pmtu+0x160/0x160 [ 24.367604] ? __sk_dst_check+0x1a5/0x380 [ 24.371727] ? sock_kzfree_s+0x60/0x60 [ 24.376281] l2tp_xmit_skb+0x105f/0x1410 [ 24.380330] ? l2tp_session_create+0xb80/0xb80 [ 24.384888] ? sock_wmalloc+0x15d/0x1d0 [ 24.388836] ? iov_iter_advance+0x13f0/0x13f0 [ 24.393323] ? pppol2tp_sendmsg+0x41b/0x670 [ 24.397631] pppol2tp_sendmsg+0x470/0x670 [ 24.401764] ? selinux_socket_sendmsg+0x36/0x40 [ 24.406412] ? pppol2tp_getsockopt+0x900/0x900 [ 24.410967] sock_sendmsg+0xca/0x110 [ 24.414658] SYSC_sendto+0x361/0x5c0 [ 24.418347] ? SYSC_connect+0x4a0/0x4a0 [ 24.422303] ? inet_dgram_connect+0x172/0x1f0 [ 24.426770] ? SYSC_connect+0x2e0/0x4a0 [ 24.430756] ? mm_fault_error+0x2c0/0x2c0 [ 24.434878] ? move_addr_to_kernel+0x60/0x60 [ 24.439262] SyS_sendto+0x40/0x50 [ 24.442687] ? SyS_getpeername+0x30/0x30 [ 24.446720] do_syscall_64+0x281/0x940 [ 24.450580] ? __do_page_fault+0xc90/0xc90 [ 24.454786] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 24.459515] ? syscall_return_slowpath+0x550/0x550 [ 24.464417] ? syscall_return_slowpath+0x2ac/0x550 [ 24.469317] ? prepare_exit_to_usermode+0x350/0x350 [ 24.474318] ? entry_SYSCALL_64_after_hwframe+0x52/0xb7 [ 24.479657] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 24.484479] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 24.489639] RIP: 0033:0x43ffe9 [ 24.492797] RSP: 002b:00007ffebeed1118 EFLAGS: 00000216 ORIG_RAX: 000000000000002c [ 24.500474] RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 000000000043ffe9 [ 24.507717] RDX: 0000000000000000 RSI: 0000000020001180 RDI: 0000000000000004 [ 24.514958] RBP: 00000000006ca018 R08: 00000000200021c0 R09: 0000000000000080 [ 24.522199] R10: 0000000000040001 R11: 0000000000000216 R12: 0000000000401910 [ 24.529440] R13: 00000000004019a0 R14: 0000000000000000 R15: 0000000000000000 [ 24.536710] [ 24.538311] Allocated by task 7: [ 24.541652] save_stack+0x43/0xd0 [ 24.545077] kasan_kmalloc+0xad/0xe0 [ 24.548762] kasan_slab_alloc+0x12/0x20 [ 24.552706] kmem_cache_alloc+0x12e/0x760 [ 24.556825] dst_alloc+0x11f/0x1a0 [ 24.560337] rt_dst_alloc+0xe9/0x4e0 [ 24.564019] ip_route_input_slow+0x1284/0x3c80 [ 24.568572] ip_route_input_rcu+0xf1/0xd20 [ 24.572778] ip_route_input_noref+0xf5/0x1e0 [ 24.577157] ip_rcv_finish+0x3a6/0x2040 [ 24.581116] ip_rcv+0xb76/0x1820 [ 24.584462] __netif_receive_skb_core+0x1a41/0x3460 [ 24.589453] __netif_receive_skb+0x2c/0x1b0 [ 24.593746] netif_receive_skb_internal+0x10b/0x670 [ 24.598732] napi_gro_receive+0x3d0/0x500 [ 24.602850] receive_buf+0xb6f/0x2530 [ 24.606622] virtnet_poll+0x320/0xb70 [ 24.610392] net_rx_action+0x792/0x1910 [ 24.614337] __do_softirq+0x2d7/0xb85 [ 24.618103] [ 24.619700] Freed by task 2067: [ 24.622951] save_stack+0x43/0xd0 [ 24.626374] __kasan_slab_free+0x11a/0x170 [ 24.630576] kasan_slab_free+0xe/0x10 [ 24.634348] kmem_cache_free+0x83/0x2a0 [ 24.638291] dst_destroy+0x257/0x370 [ 24.641972] dst_destroy_rcu+0x16/0x20 [ 24.645830] rcu_process_callbacks+0xd6c/0x17f0 [ 24.650468] __do_softirq+0x2d7/0xb85 [ 24.654236] [ 24.655836] The buggy address belongs to the object at ffff8801d6d87f00 [ 24.655836] which belongs to the cache ip_dst_cache of size 160 [ 24.668554] The buggy address is located 24 bytes inside of [ 24.668554] 160-byte region [ffff8801d6d87f00, ffff8801d6d87fa0) [ 24.680310] The buggy address belongs to the page: [ 24.685208] page:ffffea00075b61c0 count:1 mapcount:0 mapping:ffff8801d6d87000 index:0xffff8801d6d87000 [ 24.694625] flags: 0x2fffc0000000100(slab) [ 24.698831] raw: 02fffc0000000100 ffff8801d6d87000 ffff8801d6d87000 0000000100000007 [ 24.706682] raw: ffff8801d6bce538 ffffea0007158d60 ffff8801d540ee00 0000000000000000 [ 24.714539] page dumped because: kasan: bad access detected [ 24.720217] [ 24.721822] Memory state around the buggy address: [ 24.726720] ffff8801d6d87e00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 24.734050] ffff8801d6d87e80: 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc [ 24.741381] >ffff8801d6d87f00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 24.748708] ^ [ 24.752839] ffff8801d6d87f80: fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc [ 24.760167] ffff8801d6d88000: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb [ 24.767493] ================================================================== [ 24.774822] Disabling lock debugging due to kernel taint [ 24.780269] Kernel panic - not syncing: panic_on_warn set ... [ 24.780269] [ 24.787612] CPU: 0 PID: 4125 Comm: syzkaller307432 Tainted: G B 4.16.0-rc4+ #260 [ 24.796327] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 24.805648] Call Trace: [ 24.808208] dump_stack+0x194/0x24d [ 24.811803] ? arch_local_irq_restore+0x53/0x53 [ 24.816441] ? kasan_end_report+0x32/0x50 [ 24.820561] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 24.825284] ? vsnprintf+0x1ed/0x1900 [ 24.829054] ? ip6_xmit+0x1eb0/0x2260 [ 24.832826] panic+0x1e4/0x41c [ 24.835992] ? refcount_error_report+0x214/0x214 [ 24.840719] ? add_taint+0x1c/0x50 [ 24.844226] ? add_taint+0x1c/0x50 [ 24.847735] ? ip6_xmit+0x1f76/0x2260 [ 24.851504] kasan_end_report+0x50/0x50 [ 24.855445] kasan_report+0x149/0x360 [ 24.859218] __asan_report_load8_noabort+0x14/0x20 [ 24.864114] ip6_xmit+0x1f76/0x2260 [ 24.867718] ? ip6_finish_output2+0x23d0/0x23d0 [ 24.872357] ? fl6_update_dst+0x127/0x2b0 [ 24.876481] ? inet6_csk_route_socket+0x691/0xe80 [ 24.881295] ? trace_hardirqs_off+0x10/0x10 [ 24.885588] ? lock_acquire+0x1d5/0x580 [ 24.889529] ? lock_acquire+0x1d5/0x580 [ 24.893474] ? inet6_csk_xmit+0x114/0x580 [ 24.897591] ? trace_hardirqs_off+0x10/0x10 [ 24.901886] ? lock_release+0xa40/0xa40 [ 24.905835] inet6_csk_xmit+0x2fc/0x580 [ 24.909780] ? inet6_csk_update_pmtu+0x160/0x160 [ 24.914510] ? __sk_dst_check+0x1a5/0x380 [ 24.918627] ? sock_kzfree_s+0x60/0x60 [ 24.922493] l2tp_xmit_skb+0x105f/0x1410 [ 24.926527] ? l2tp_session_create+0xb80/0xb80 [ 24.931076] ? sock_wmalloc+0x15d/0x1d0 [ 24.935025] ? iov_iter_advance+0x13f0/0x13f0 [ 24.939491] ? pppol2tp_sendmsg+0x41b/0x670 [ 24.943781] pppol2tp_sendmsg+0x470/0x670 [ 24.947900] ? selinux_socket_sendmsg+0x36/0x40 [ 24.952538] ? pppol2tp_getsockopt+0x900/0x900 [ 24.957090] sock_sendmsg+0xca/0x110 [ 24.960775] SYSC_sendto+0x361/0x5c0 [ 24.964460] ? SYSC_connect+0x4a0/0x4a0 [ 24.968410] ? inet_dgram_connect+0x172/0x1f0 [ 24.972876] ? SYSC_connect+0x2e0/0x4a0 [ 24.976835] ? mm_fault_error+0x2c0/0x2c0 [ 24.980950] ? move_addr_to_kernel+0x60/0x60 [ 24.985328] SyS_sendto+0x40/0x50 [ 24.988749] ? SyS_getpeername+0x30/0x30 [ 24.992780] do_syscall_64+0x281/0x940 [ 24.996637] ? __do_page_fault+0xc90/0xc90 [ 25.000838] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 25.005563] ? syscall_return_slowpath+0x550/0x550 [ 25.010463] ? syscall_return_slowpath+0x2ac/0x550 [ 25.015362] ? prepare_exit_to_usermode+0x350/0x350 [ 25.020354] ? entry_SYSCALL_64_after_hwframe+0x52/0xb7 [ 25.025689] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 25.030502] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 25.035664] RIP: 0033:0x43ffe9 [ 25.038824] RSP: 002b:00007ffebeed1118 EFLAGS: 00000216 ORIG_RAX: 000000000000002c [ 25.046500] RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 000000000043ffe9 [ 25.053737] RDX: 0000000000000000 RSI: 0000000020001180 RDI: 0000000000000004 [ 25.060974] RBP: 00000000006ca018 R08: 00000000200021c0 R09: 0000000000000080 [ 25.068213] R10: 0000000000040001 R11: 0000000000000216 R12: 0000000000401910 [ 25.075458] R13: 00000000004019a0 R14: 0000000000000000 R15: 0000000000000000 [ 25.083149] Dumping ftrace buffer: [ 25.086660] (ftrace buffer empty) [ 25.090337] Kernel Offset: disabled [ 25.093934] Rebooting in 86400 seconds..