[....] Starting enhanced syslogd: rsyslogd[ 12.334235] audit: type=1400 audit(1516419202.718:5): avc: denied { syslog } for pid=3510 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: [ 20.539338] audit: type=1400 audit(1516419210.922:6): avc: denied { map } for pid=3650 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 '10.128.0.47' (ECDSA) to the list of known hosts. executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 41.090449] audit: type=1400 audit(1516419231.474:7): avc: denied { map } for pid=3667 comm="syzkaller538740" path="/root/syzkaller538740346" 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 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing 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executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing 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executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing 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executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing 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executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 47.263300] ================================================================== [ 47.270739] BUG: KASAN: use-after-free in pppol2tp_connect+0x1a91/0x1dd0 [ 47.277559] Read of size 8 at addr ffff8801d3fa99e8 by task syzkaller538740/4979 [ 47.285060] [ 47.286662] CPU: 0 PID: 4979 Comm: syzkaller538740 Not tainted 4.15.0-rc8-mm1+ #58 [ 47.294336] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.303662] Call Trace: [ 47.306228] dump_stack+0x194/0x257 [ 47.309833] ? arch_local_irq_restore+0x53/0x53 [ 47.314474] ? show_regs_print_info+0x18/0x18 [ 47.318948] ? pppol2tp_connect+0x1a91/0x1dd0 [ 47.323417] print_address_description+0x73/0x250 [ 47.328231] ? pppol2tp_connect+0x1a91/0x1dd0 [ 47.332699] kasan_report+0x23b/0x360 [ 47.336475] __asan_report_load8_noabort+0x14/0x20 [ 47.341378] pppol2tp_connect+0x1a91/0x1dd0 [ 47.345681] ? pppol2tp_recv_payload_hook+0x1b0/0x1b0 [ 47.350858] ? selinux_netlbl_socket_connect+0x76/0x1b0 [ 47.356195] ? selinux_socket_connect+0x311/0x730 [ 47.361012] ? lock_downgrade+0x980/0x980 [ 47.365128] ? lock_downgrade+0x980/0x980 [ 47.369255] ? selinux_socket_setsockopt+0x80/0x80 [ 47.374153] ? lock_release+0xa40/0xa40 [ 47.378101] ? trace_event_raw_event_sched_switch+0x800/0x800 [ 47.383957] ? __check_object_size+0x8b/0x530 [ 47.388425] ? handle_mm_fault+0x476/0x930 [ 47.392637] ? __might_sleep+0x95/0x190 [ 47.396595] ? security_socket_connect+0x89/0xb0 [ 47.401329] SYSC_connect+0x213/0x4a0 [ 47.405113] ? SYSC_bind+0x410/0x410 [ 47.408805] ? do_page_fault+0xee/0x720 [ 47.412753] ? __do_page_fault+0xc90/0xc90 [ 47.416969] ? sock_map_fd+0x53/0x90 [ 47.420658] ? SyS_socket+0x12d/0x1d0 [ 47.424437] ? entry_SYSCALL_64_fastpath+0x5/0xa0 [ 47.429256] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 47.434423] SyS_connect+0x24/0x30 [ 47.437935] entry_SYSCALL_64_fastpath+0x29/0xa0 [ 47.442663] RIP: 0033:0x4407d9 [ 47.445822] RSP: 002b:00007ffe979ec4a8 EFLAGS: 00000203 ORIG_RAX: 000000000000002a [ 47.453507] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000004407d9 [ 47.460832] RDX: 000000000000002e RSI: 00000000205fafd2 RDI: 0000000000000005 [ 47.468076] RBP: 000000000000b89b R08: 0000000000000000 R09: 0000000000000000 [ 47.475321] R10: 0000000000000000 R11: 0000000000000203 R12: 0000000000000000 [ 47.482562] R13: 0000000000401cd0 R14: 0000000000000000 R15: 0000000000000000 [ 47.489821] [ 47.491424] Allocated by task 4977: [ 47.495029] save_stack+0x43/0xd0 [ 47.498452] kasan_kmalloc+0xad/0xe0 [ 47.502135] kasan_slab_alloc+0x12/0x20 [ 47.506078] kmem_cache_alloc+0x12e/0x760 [ 47.510200] sk_prot_alloc+0x65/0x2a0 [ 47.513970] sk_alloc+0x105/0x1440 [ 47.517482] inet6_create+0x44d/0x10f0 [ 47.521341] __sock_create+0x4d4/0x850 [ 47.525197] SyS_socket+0xeb/0x1d0 [ 47.528717] entry_SYSCALL_64_fastpath+0x29/0xa0 [ 47.533444] [ 47.535042] Freed by task 4979: [ 47.538299] save_stack+0x43/0xd0 [ 47.541723] __kasan_slab_free+0x11a/0x170 [ 47.545928] kasan_slab_free+0xe/0x10 [ 47.549701] kmem_cache_free+0x86/0x2b0 [ 47.553646] __sk_destruct+0x628/0x920 [ 47.557504] sk_destruct+0x47/0x80 [ 47.561016] __sk_free+0xf1/0x2b0 [ 47.564439] sk_free+0x2a/0x40 [ 47.567605] l2tp_session_free+0x21c/0x2b0 [ 47.571818] pppol2tp_session_destruct+0xd4/0x110 [ 47.576638] __sk_destruct+0xfd/0x920 [ 47.580409] sk_destruct+0x47/0x80 [ 47.583925] __sk_free+0xf1/0x2b0 [ 47.587349] sk_free+0x2a/0x40 [ 47.590512] pppol2tp_put_sk+0x49/0x60 [ 47.594371] rcu_process_callbacks+0xd6c/0x17f0 [ 47.599011] __do_softirq+0x2d7/0xb85 [ 47.602787] [ 47.604387] The buggy address belongs to the object at ffff8801d3fa97c0 [ 47.604387] which belongs to the cache UDPv6 of size 1664 [ 47.616580] The buggy address is located 552 bytes inside of [ 47.616580] 1664-byte region [ffff8801d3fa97c0, ffff8801d3fa9e40) [ 47.628512] The buggy address belongs to the page: [ 47.633422] page:ffffea00074fea40 count:1 mapcount:0 mapping:ffff8801d3fa90c0 index:0x0 [ 47.641543] flags: 0x2fffc0000000100(slab) [ 47.645751] raw: 02fffc0000000100 ffff8801d3fa90c0 0000000000000000 0000000100000002 [ 47.653610] raw: ffffea00074f42a0 ffffea0007530220 ffff8801d32cd9c0 0000000000000000 [ 47.661576] page dumped because: kasan: bad access detected [ 47.667268] [ 47.668868] Memory state around the buggy address: [ 47.673778] ffff8801d3fa9880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 47.681123] ffff8801d3fa9900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 47.688466] >ffff8801d3fa9980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 47.695800] ^ [ 47.702524] ffff8801d3fa9a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 47.709852] ffff8801d3fa9a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 47.717187] ================================================================== [ 47.724512] Disabling lock debugging due to kernel taint [ 47.730231] Kernel panic - not syncing: panic_on_warn set ... [ 47.730231] [ 47.737671] CPU: 0 PID: 4979 Comm: syzkaller538740 Tainted: G B 4.15.0-rc8-mm1+ #58 [ 47.746665] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.755989] Call Trace: [ 47.758553] dump_stack+0x194/0x257 [ 47.762156] ? arch_local_irq_restore+0x53/0x53 [ 47.766799] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 47.771526] ? vsnprintf+0x1ed/0x1900 [ 47.775302] ? pppol2tp_connect+0x19a0/0x1dd0 [ 47.779770] panic+0x1e4/0x41c [ 47.782945] ? refcount_error_report+0x214/0x214 [ 47.787673] ? add_taint+0x1c/0x50 [ 47.791182] ? add_taint+0x1c/0x50 [ 47.794693] ? pppol2tp_connect+0x1a91/0x1dd0 [ 47.799157] kasan_end_report+0x50/0x50 [ 47.803097] kasan_report+0x148/0x360 [ 47.806869] __asan_report_load8_noabort+0x14/0x20 [ 47.811765] pppol2tp_connect+0x1a91/0x1dd0 [ 47.816061] ? pppol2tp_recv_payload_hook+0x1b0/0x1b0 [ 47.821228] ? selinux_netlbl_socket_connect+0x76/0x1b0 [ 47.826566] ? selinux_socket_connect+0x311/0x730 [ 47.831382] ? lock_downgrade+0x980/0x980 [ 47.835497] ? lock_downgrade+0x980/0x980 [ 47.839622] ? selinux_socket_setsockopt+0x80/0x80 [ 47.844522] ? lock_release+0xa40/0xa40 [ 47.848470] ? trace_event_raw_event_sched_switch+0x800/0x800 [ 47.854326] ? __check_object_size+0x8b/0x530 [ 47.858791] ? handle_mm_fault+0x476/0x930 [ 47.863001] ? __might_sleep+0x95/0x190 [ 47.866958] ? security_socket_connect+0x89/0xb0 [ 47.871689] SYSC_connect+0x213/0x4a0 [ 47.875459] ? SYSC_bind+0x410/0x410 [ 47.879148] ? do_page_fault+0xee/0x720 [ 47.883101] ? __do_page_fault+0xc90/0xc90 [ 47.887318] ? sock_map_fd+0x53/0x90 [ 47.891004] ? SyS_socket+0x12d/0x1d0 [ 47.894783] ? entry_SYSCALL_64_fastpath+0x5/0xa0 [ 47.899682] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 47.904672] SyS_connect+0x24/0x30 [ 47.908185] entry_SYSCALL_64_fastpath+0x29/0xa0 [ 47.912909] RIP: 0033:0x4407d9 [ 47.916067] RSP: 002b:00007ffe979ec4a8 EFLAGS: 00000203 ORIG_RAX: 000000000000002a [ 47.923744] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000004407d9 [ 47.930990] RDX: 000000000000002e RSI: 00000000205fafd2 RDI: 0000000000000005 [ 47.938240] RBP: 000000000000b89b R08: 0000000000000000 R09: 0000000000000000 [ 47.945495] R10: 0000000000000000 R11: 0000000000000203 R12: 0000000000000000 [ 47.952741] R13: 0000000000401cd0 R14: 0000000000000000 R15: 0000000000000000 [ 47.960404] Dumping ftrace buffer: [ 47.963916] (ftrace buffer empty) [ 47.967594] Kernel Offset: disabled [ 47.971192] Rebooting in 86400 seconds..