[....] Starting enhanced syslogd: rsyslogd[ 11.551156] audit: type=1400 audit(1515620899.553:4): avc: denied { syslog } for pid=3174 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 '10.128.0.59' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 23.664044] ================================================================== [ 23.671464] BUG: KASAN: slab-out-of-bounds in sg_remove_request+0x103/0x120 [ 23.678536] Read of size 8 at addr ffff8801cbd32140 by task syzkaller432729/3331 [ 23.686032] [ 23.687629] CPU: 1 PID: 3331 Comm: syzkaller432729 Not tainted 4.9.76-g9154940 #20 [ 23.695302] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 23.704625] ffff8801cae0fa50 ffffffff81d93149 ffffea00072f4c80 ffff8801cbd32140 [ 23.712579] 0000000000000000 ffff8801cbd32140 ffff8801d068c438 ffff8801cae0fa88 [ 23.720533] ffffffff8153cb43 ffff8801cbd32140 0000000000000008 0000000000000000 [ 23.728490] Call Trace: [ 23.731049] [] dump_stack+0xc1/0x128 [ 23.736394] [] print_address_description+0x73/0x280 [ 23.743028] [] kasan_report+0x275/0x360 [ 23.748621] [] ? sg_remove_request+0x103/0x120 [ 23.754826] [] __asan_report_load8_noabort+0x14/0x20 [ 23.761546] [] sg_remove_request+0x103/0x120 [ 23.767583] [] sg_finish_rem_req+0x295/0x340 [ 23.773607] [] sg_read+0xa1c/0x1440 [ 23.778855] [] ? sg_proc_seq_show_debug+0xd10/0xd10 [ 23.785490] [] ? __raw_spin_lock_init+0x1c/0x100 [ 23.791866] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 23.798678] [] ? sg_proc_seq_show_debug+0xd10/0xd10 [ 23.805312] [] __vfs_read+0x103/0x670 [ 23.810730] [] ? default_llseek+0x290/0x290 [ 23.816672] [] ? fsnotify+0x86/0xf30 [ 23.822012] [] ? fsnotify+0xf30/0xf30 [ 23.828059] [] ? avc_policy_seqno+0x9/0x20 [ 23.833916] [] ? selinux_file_permission+0x82/0x460 [ 23.840549] [] ? security_file_permission+0x89/0x1e0 [ 23.847276] [] ? rw_verify_area+0xe5/0x2b0 [ 23.853128] [] vfs_read+0x11e/0x380 [ 23.858372] [] SyS_read+0xd9/0x1b0 [ 23.863544] [] ? vfs_copy_file_range+0x740/0x740 [ 23.869921] [] ? do_fast_syscall_32+0xcf/0x890 [ 23.876121] [] ? vfs_copy_file_range+0x740/0x740 [ 23.882494] [] do_fast_syscall_32+0x2f7/0x890 [ 23.888615] [] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 23.895248] [] entry_SYSENTER_compat+0x74/0x83 [ 23.901453] [ 23.903046] Allocated by task 0: [ 23.906376] (stack is not available) [ 23.910062] [ 23.911656] Freed by task 0: [ 23.914641] (stack is not available) [ 23.918327] [ 23.919922] The buggy address belongs to the object at ffff8801cbd32100 [ 23.919922] which belongs to the cache fasync_cache of size 96 [ 23.932547] The buggy address is located 64 bytes inside of [ 23.932547] 96-byte region [ffff8801cbd32100, ffff8801cbd32160) [ 23.944218] The buggy address belongs to the page: [ 23.949118] page:ffffea00072f4c80 count:1 mapcount:0 mapping: (null) index:0x0 [ 23.957339] flags: 0x8000000000000080(slab) [ 23.961621] page dumped because: kasan: bad access detected [ 23.967294] [ 23.968888] Memory state around the buggy address: [ 23.973781] ffff8801cbd32000: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc [ 23.981114] ffff8801cbd32080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 23.988441] >ffff8801cbd32100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 23.995869] ^ [ 24.001284] ffff8801cbd32180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 24.008623] ffff8801cbd32200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 24.015974] ================================================================== [ 24.023307] Disabling lock debugging due to kernel taint [ 24.028832] Kernel panic - not syncing: panic_on_warn set ... [ 24.028832] [ 24.036171] CPU: 1 PID: 3331 Comm: syzkaller432729 Tainted: G B 4.9.76-g9154940 #20 [ 24.045059] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 24.054385] ffff8801cae0f9a8 ffffffff81d93149 ffffffff84195c17 ffff8801cae0fa80 [ 24.062344] 0000000000000000 ffff8801cbd32140 ffff8801d068c438 ffff8801cae0fa70 [ 24.070301] ffffffff8142e371 0000000041b58ab3 ffffffff84189678 ffffffff8142e1b5 [ 24.078256] Call Trace: [ 24.080903] [] dump_stack+0xc1/0x128 [ 24.086239] [] panic+0x1bc/0x3a8 [ 24.091226] [] ? percpu_up_read_preempt_enable.constprop.53+0xd7/0xd7 [ 24.099438] [] ? preempt_schedule+0x25/0x30 [ 24.105385] [] ? ___preempt_schedule+0x16/0x18 [ 24.111589] [] kasan_end_report+0x50/0x50 [ 24.117353] [] kasan_report+0x167/0x360 [ 24.122946] [] ? sg_remove_request+0x103/0x120 [ 24.129148] [] __asan_report_load8_noabort+0x14/0x20 [ 24.135868] [] sg_remove_request+0x103/0x120 [ 24.141904] [] sg_finish_rem_req+0x295/0x340 [ 24.147933] [] sg_read+0xa1c/0x1440 [ 24.153267] [] ? sg_proc_seq_show_debug+0xd10/0xd10 [ 24.159907] [] ? __raw_spin_lock_init+0x1c/0x100 [ 24.166293] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 24.173117] [] ? sg_proc_seq_show_debug+0xd10/0xd10 [ 24.179759] [] __vfs_read+0x103/0x670 [ 24.185179] [] ? default_llseek+0x290/0x290 [ 24.191129] [] ? fsnotify+0x86/0xf30 [ 24.196472] [] ? fsnotify+0xf30/0xf30 [ 24.201899] [] ? avc_policy_seqno+0x9/0x20 [ 24.207771] [] ? selinux_file_permission+0x82/0x460 [ 24.214413] [] ? security_file_permission+0x89/0x1e0 [ 24.221134] [] ? rw_verify_area+0xe5/0x2b0 [ 24.226998] [] vfs_read+0x11e/0x380 [ 24.232336] [] SyS_read+0xd9/0x1b0 [ 24.237495] [] ? vfs_copy_file_range+0x740/0x740 [ 24.243870] [] ? do_fast_syscall_32+0xcf/0x890 [ 24.250072] [] ? vfs_copy_file_range+0x740/0x740 [ 24.256446] [] do_fast_syscall_32+0x2f7/0x890 [ 24.262559] [] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 24.269206] [] entry_SYSENTER_compat+0x74/0x83 [ 24.275444] Dumping ftrace buffer: [ 24.278953] (ftrace buffer empty) [ 24.282639] Kernel Offset: disabled [ 24.286235] Rebooting in 86400 seconds..