[....] Starting enhanced syslogd: rsyslogd[ 10.141501] audit: type=1400 audit(1515671689.748:4): avc: denied { syslog } for pid=3178 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 Warning: Permanently added '10.128.0.4' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 40.015613] ================================================================== [ 40.016646] BUG: KASAN: slab-out-of-bounds in sg_remove_request+0x103/0x120 [ 40.017589] Read of size 8 at addr ffff8801cb58f140 by task syzkaller211586/3350 [ 40.018628] [ 40.018882] CPU: 0 PID: 3350 Comm: syzkaller211586 Not tainted 4.9.76-g9154940 #20 [ 40.019887] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 40.021127] ffff8801c7e7fa50 ffffffff81d93149 ffffea00072d63c0 ffff8801cb58f140 [ 40.022278] 0000000000000000 ffff8801cb58f140 ffff8801c7c64438 ffff8801c7e7fa88 [ 40.023432] ffffffff8153cb43 ffff8801cb58f140 0000000000000008 0000000000000000 [ 40.024564] Call Trace: [ 40.024920] [] dump_stack+0xc1/0x128 [ 40.025656] [] print_address_description+0x73/0x280 [ 40.026529] [] kasan_report+0x275/0x360 [ 40.027271] [] ? sg_remove_request+0x103/0x120 [ 40.028123] [] __asan_report_load8_noabort+0x14/0x20 [ 40.029025] [] sg_remove_request+0x103/0x120 [ 40.029823] [] sg_finish_rem_req+0x295/0x340 [ 40.030629] [] sg_read+0xa1c/0x1440 [ 40.031329] [] ? __raw_spin_lock_init+0x1c/0x100 [ 40.032169] [] ? sg_proc_seq_show_debug+0xd10/0xd10 [ 40.033046] [] ? _raw_spin_unlock+0x2c/0x50 [ 40.033845] [] ? fasync_insert_entry+0x147/0x2e0 [ 40.034749] [] ? sg_proc_seq_show_debug+0xd10/0xd10 [ 40.035651] [] __vfs_read+0x103/0x670 [ 40.040782] [] ? default_llseek+0x290/0x290 [ 40.046729] [] ? fsnotify+0x86/0xf30 [ 40.052055] [] ? fsnotify+0xf30/0xf30 [ 40.057471] [] ? avc_policy_seqno+0x9/0x20 [ 40.063321] [] ? selinux_file_permission+0x82/0x460 [ 40.070123] [] ? security_file_permission+0x89/0x1e0 [ 40.076845] [] ? rw_verify_area+0xe5/0x2b0 [ 40.082696] [] vfs_read+0x11e/0x380 [ 40.087938] [] SyS_read+0xd9/0x1b0 [ 40.093095] [] ? vfs_copy_file_range+0x740/0x740 [ 40.099467] [] ? compat_SyS_ioctl+0x8c/0x2050 [ 40.105579] [] ? do_fast_syscall_32+0xcf/0x890 [ 40.111774] [] ? vfs_copy_file_range+0x740/0x740 [ 40.118150] [] do_fast_syscall_32+0x2f7/0x890 [ 40.124262] [] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 40.130894] [] entry_SYSENTER_compat+0x74/0x83 [ 40.137089] [ 40.138684] Allocated by task 0: [ 40.142009] (stack is not available) [ 40.145689] [ 40.147279] Freed by task 0: [ 40.150262] (stack is not available) [ 40.153935] [ 40.155531] The buggy address belongs to the object at ffff8801cb58f100 [ 40.155531] which belongs to the cache fasync_cache of size 96 [ 40.168146] The buggy address is located 64 bytes inside of [ 40.168146] 96-byte region [ffff8801cb58f100, ffff8801cb58f160) [ 40.179807] The buggy address belongs to the page: [ 40.184872] page:ffffea00072d63c0 count:1 mapcount:0 mapping: (null) index:0x0 [ 40.193088] flags: 0x8000000000000080(slab) [ 40.197373] page dumped because: kasan: bad access detected [ 40.203044] [ 40.204634] Memory state around the buggy address: [ 40.209526] ffff8801cb58f000: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc [ 40.216850] ffff8801cb58f080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 40.224348] >ffff8801cb58f100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 40.231670] ^ [ 40.237084] ffff8801cb58f180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 40.245534] ffff8801cb58f200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 40.252856] ================================================================== [ 40.260176] Disabling lock debugging due to kernel taint [ 40.265663] Kernel panic - not syncing: panic_on_warn set ... [ 40.265663] [ 40.272999] CPU: 0 PID: 3350 Comm: syzkaller211586 Tainted: G B 4.9.76-g9154940 #20 [ 40.281887] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 40.291210] ffff8801c7e7f9a8 ffffffff81d93149 ffffffff84195c17 ffff8801c7e7fa80 [ 40.299157] 0000000000000000 ffff8801cb58f140 ffff8801c7c64438 ffff8801c7e7fa70 [ 40.307103] ffffffff8142e371 0000000041b58ab3 ffffffff84189678 ffffffff8142e1b5 [ 40.315051] Call Trace: [ 40.317606] [] dump_stack+0xc1/0x128 [ 40.322933] [] panic+0x1bc/0x3a8 [ 40.327914] [] ? percpu_up_read_preempt_enable.constprop.53+0xd7/0xd7 [ 40.336108] [] ? preempt_schedule+0x25/0x30 [ 40.342390] [] ? ___preempt_schedule+0x16/0x18 [ 40.348599] [] kasan_end_report+0x50/0x50 [ 40.354366] [] kasan_report+0x167/0x360 [ 40.360354] [] ? sg_remove_request+0x103/0x120 [ 40.366549] [] __asan_report_load8_noabort+0x14/0x20 [ 40.373263] [] sg_remove_request+0x103/0x120 [ 40.379286] [] sg_finish_rem_req+0x295/0x340 [ 40.385308] [] sg_read+0xa1c/0x1440 [ 40.390551] [] ? __raw_spin_lock_init+0x1c/0x100 [ 40.396930] [] ? sg_proc_seq_show_debug+0xd10/0xd10 [ 40.403568] [] ? _raw_spin_unlock+0x2c/0x50 [ 40.409514] [] ? fasync_insert_entry+0x147/0x2e0 [ 40.415883] [] ? sg_proc_seq_show_debug+0xd10/0xd10 [ 40.422513] [] __vfs_read+0x103/0x670 [ 40.427930] [] ? default_llseek+0x290/0x290 [ 40.433864] [] ? fsnotify+0x86/0xf30 [ 40.439191] [] ? fsnotify+0xf30/0xf30 [ 40.444868] [] ? avc_policy_seqno+0x9/0x20 [ 40.450716] [] ? selinux_file_permission+0x82/0x460 [ 40.457345] [] ? security_file_permission+0x89/0x1e0 [ 40.464060] [] ? rw_verify_area+0xe5/0x2b0 [ 40.469909] [] vfs_read+0x11e/0x380 [ 40.475148] [] SyS_read+0xd9/0x1b0 [ 40.480303] [] ? vfs_copy_file_range+0x740/0x740 [ 40.486672] [] ? compat_SyS_ioctl+0x8c/0x2050 [ 40.492782] [] ? do_fast_syscall_32+0xcf/0x890 [ 40.498980] [] ? vfs_copy_file_range+0x740/0x740 [ 40.505349] [] do_fast_syscall_32+0x2f7/0x890 [ 40.511463] [] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 40.518359] [] entry_SYSENTER_compat+0x74/0x83 [ 40.524591] Dumping ftrace buffer: [ 40.528097] (ftrace buffer empty) [ 40.531771] Kernel Offset: disabled [ 40.535368] Rebooting in 86400 seconds..