INIT: Entering runlevel: 2 [info] Using makefile-style concurrent boot in runlevel 2. [....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.10.14' (ECDSA) to the list of known hosts. 2018/04/06 04:22:18 parsed 1 programs 2018/04/06 04:22:18 executed programs: 0 syzkaller login: [ 37.314033] IPVS: Creating netns size=2536 id=1 RESULT: signal 0, coverage 0 errno 0 RESULT: signal 0, coverage 0 errno 0 RESULT: signal 0, coverage 0 errno 0 RESULT: signal 0, coverage 0 errno 0 RESULT: signal 0, coverage 0 errno 0 RESULT: signal 0, coverage 0 errno 0 RESULT: signal 0, coverage 0 errno 0 RESULT: signal 0, coverage 0 errno 0 RESULT: signal 0, coverage 0 errno 0 RESULT: signal 0, coverage 0 errno 0 RESULT: signal 0, coverage 0 errno 0 RESULT: signal 0, coverage 0 errno 0 RESULT: signal 0, coverage 0 errno 0 RESULT: signal 0, coverage 0 errno 0 RESULT: signal 0, coverage 0 errno 0 RESULT: signal 0, coverage 0 errno 0 RESULT: signal 0, coverage 0 errno 0 RESULT: signal 0, coverage 0 errno 0 RESULT: signal 0, coverage 0 errno 0 RESULT: signal 0, coverage 0 errno 0 RESULT: signal 0, coverage 0 errno 0 RESULT: signal 0, coverage 0 errno 0 RESULT: signal 0, coverage 0 errno 0 RESULT: signal 0, coverage 0 errno 0 RESULT: signal 0, coverage 0 errno 0 RESULT: signal 0, coverage 0 errno 0 RESULT: signal 0, coverage 0 errno 0 RESULT: signal 0, coverage 0 errno 0 RESULT: signal 0, coverage 0 errno 0 RESULT: signal 0, coverage 0 errno 0 RESULT: signal 0, coverage 0 errno 0 RESULT: signal 0, coverage 0 errno 0 2018/04/06 04:22:23 executed programs: 32 RESULT: signal 0, coverage 0 errno 0 RESULT: signal 0, coverage 0 errno 0 RESULT: signal 0, coverage 0 errno 0 RESULT: signal 0, coverage 0 errno 0 RESULT: signal 0, coverage 0 errno 0 RESULT: signal 0, coverage 0 errno 0 RESULT: signal 0, coverage 0 errno 0 RESULT: signal 0, coverage 0 errno 0 RESULT: signal 0, coverage 0 errno 0 RESULT: signal 0, coverage 0 errno 0 RESULT: signal 0, coverage 0 errno 0 RESULT: signal 0, coverage 0 errno 0 [ 44.596062] ================================================================== [ 44.603439] BUG: KASAN: use-after-free in l2tp_session_queue_purge+0xf4/0x100 [ 44.610688] Read of size 4 at addr ffff8801b9e46f00 by task syz-executor0/3975 [ 44.618010] [ 44.619611] CPU: 1 PID: 3975 Comm: syz-executor0 Not tainted 4.9.92-g7cd9561 #1 [ 44.627023] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 44.636343] ffff8801d7177ca0 ffffffff81d9c489 ffffea0006e79180 ffff8801b9e46f00 [ 44.644306] 0000000000000000 ffff8801b9e46f00 ffffffff82ef0be0 ffff8801d7177cd8 [ 44.652268] ffffffff8156556b ffff8801b9e46f00 0000000000000004 0000000000000000 [ 44.660233] Call Trace: [ 44.662789] [] dump_stack+0xc1/0x128 [ 44.668119] [] ? sock_release+0x1c0/0x1c0 [ 44.673884] [] print_address_description+0x6c/0x234 [ 44.680516] [] ? sock_release+0x1c0/0x1c0 [ 44.686278] [] kasan_report.cold.6+0xac/0x2f5 [ 44.692566] [] ? l2tp_session_queue_purge+0xf4/0x100 [ 44.699287] [] __asan_report_load4_noabort+0x14/0x20 [ 44.706008] [] l2tp_session_queue_purge+0xf4/0x100 [ 44.712553] [] ? sock_release+0x1c0/0x1c0 [ 44.718317] [] pppol2tp_release+0x1fb/0x2e0 [ 44.724256] [] sock_release+0x96/0x1c0 [ 44.729780] [] sock_close+0x16/0x20 [ 44.735025] [] __fput+0x263/0x700 [ 44.740100] [] ____fput+0x15/0x20 [ 44.745173] [] task_work_run+0x10c/0x180 [ 44.750853] [] exit_to_usermode_loop+0xfc/0x120 [ 44.757136] [] do_fast_syscall_32+0x5c3/0x870 [ 44.763249] [] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 44.769881] [] entry_SYSENTER_compat+0x90/0xa2 [ 44.776076] [ 44.777670] Allocated by task 3975: [ 44.781266] save_stack_trace+0x16/0x20 [ 44.785206] save_stack+0x43/0xd0 [ 44.788624] kasan_kmalloc+0xc7/0xe0 [ 44.792308] __kmalloc+0x11d/0x300 [ 44.795814] l2tp_session_create+0x38/0x1760 [ 44.800187] pppol2tp_connect+0x10c5/0x18e0 [ 44.804477] SYSC_connect+0x1b8/0x300 [ 44.808243] SyS_connect+0x24/0x30 [ 44.811750] do_fast_syscall_32+0x2f7/0x870 [ 44.816039] entry_SYSENTER_compat+0x90/0xa2 [ 44.820409] [ 44.822003] Freed by task 3974: [ 44.825254] save_stack_trace+0x16/0x20 [ 44.829195] save_stack+0x43/0xd0 [ 44.832614] kasan_slab_free+0x72/0xc0 [ 44.836473] kfree+0xfb/0x310 [ 44.839543] l2tp_session_free+0x166/0x200 [ 44.844067] l2tp_tunnel_closeall+0x284/0x350 [ 44.848530] l2tp_udp_encap_destroy+0x87/0xe0 [ 44.852994] udpv6_destroy_sock+0xb1/0xd0 [ 44.857108] sk_common_release+0x6d/0x300 [ 44.861223] udp_lib_close+0x15/0x20 [ 44.864907] inet_release+0xff/0x1d0 [ 44.868585] inet6_release+0x50/0x70 [ 44.872266] sock_release+0x96/0x1c0 [ 44.875944] sock_close+0x16/0x20 [ 44.879363] __fput+0x263/0x700 [ 44.882607] ____fput+0x15/0x20 [ 44.885856] task_work_run+0x10c/0x180 [ 44.889723] exit_to_usermode_loop+0xfc/0x120 [ 44.894191] do_fast_syscall_32+0x5c3/0x870 [ 44.898482] entry_SYSENTER_compat+0x90/0xa2 [ 44.902854] [ 44.904450] The buggy address belongs to the object at ffff8801b9e46f00 [ 44.904450] which belongs to the cache kmalloc-512 of size 512 [ 44.917073] The buggy address is located 0 bytes inside of [ 44.917073] 512-byte region [ffff8801b9e46f00, ffff8801b9e47100) [ 44.928737] The buggy address belongs to the page: [ 44.933632] page:ffffea0006e79180 count:1 mapcount:0 mapping: (null) index:0x0 compound_mapcount: 0 [ 44.943792] flags: 0x8000000000004080(slab|head) [ 44.948511] page dumped because: kasan: bad access detected [ 44.954185] [ 44.955781] Memory state around the buggy address: [ 44.960676] ffff8801b9e46e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 44.968002] ffff8801b9e46e80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 44.975329] >ffff8801b9e46f00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 44.982651] ^ [ 44.985985] ffff8801b9e46f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 44.993312] ffff8801b9e47000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 45.000636] ================================================================== [ 45.007958] Disabling lock debugging due to kernel taint [ 45.013462] Kernel panic - not syncing: panic_on_warn set ... [ 45.013462] [ 45.020797] CPU: 1 PID: 3975 Comm: syz-executor0 Tainted: G B 4.9.92-g7cd9561 #1 [ 45.029426] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 45.038746] ffff8801d7177c00 ffffffff81d9c489 ffffffff841a85f1 00000000ffffffff [ 45.046719] 0000000000000000 0000000000000001 ffffffff82ef0be0 ffff8801d7177cc0 [ 45.054680] ffffffff8141fa55 0000000041b58ab3 ffffffff8419bd28 ffffffff8141f896 [ 45.062640] Call Trace: [ 45.065196] [] dump_stack+0xc1/0x128 [ 45.070527] [] ? sock_release+0x1c0/0x1c0 [ 45.076294] [] panic+0x1bf/0x3bc [ 45.081277] [] ? add_taint.cold.6+0x16/0x16 [ 45.087215] [] ? ___preempt_schedule+0x16/0x18 [ 45.093414] [] kasan_end_report+0x47/0x4f [ 45.099177] [] kasan_report.cold.6+0xc9/0x2f5 [ 45.105291] [] ? l2tp_session_queue_purge+0xf4/0x100 [ 45.112010] [] __asan_report_load4_noabort+0x14/0x20 [ 45.118734] [] l2tp_session_queue_purge+0xf4/0x100 [ 45.125282] [] ? sock_release+0x1c0/0x1c0 [ 45.131047] [] pppol2tp_release+0x1fb/0x2e0 [ 45.136983] [] sock_release+0x96/0x1c0 [ 45.142489] [] sock_close+0x16/0x20 [ 45.147735] [] __fput+0x263/0x700 [ 45.152805] [] ____fput+0x15/0x20 [ 45.157876] [] task_work_run+0x10c/0x180 [ 45.163553] [] exit_to_usermode_loop+0xfc/0x120 [ 45.169836] [] do_fast_syscall_32+0x5c3/0x870 [ 45.175947] [] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 45.182578] [] entry_SYSENTER_compat+0x90/0xa2 [ 45.189156] Dumping ftrace buffer: [ 45.192662] (ftrace buffer empty) [ 45.196340] Kernel Offset: disabled [ 45.199937] Rebooting in 86400 seconds..