[....] Starting enhanced syslogd: rsyslogd[ 13.322423] audit: type=1400 audit(1515947004.267:4): avc: denied { syslog } for pid=3177 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 mcstransd: [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] 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 '10.128.0.42' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 40.508321] ================================================================== [ 40.515734] BUG: KASAN: slab-out-of-bounds in sg_remove_request+0x103/0x120 [ 40.522825] Read of size 8 at addr ffff8801c7004140 by task syzkaller413484/3343 [ 40.530326] [ 40.531942] CPU: 1 PID: 3343 Comm: syzkaller413484 Not tainted 4.9.76-gf0f6293 #12 [ 40.539620] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 40.548963] ffff8801cca1fab0 ffffffff81d93149 ffffea00071c0100 ffff8801c7004140 [ 40.556991] 0000000000000000 ffff8801c7004140 ffff8801c84e8238 ffff8801cca1fae8 [ 40.564984] ffffffff8153cb43 ffff8801c7004140 0000000000000008 0000000000000000 [ 40.572967] Call Trace: [ 40.575536] [] dump_stack+0xc1/0x128 [ 40.580875] [] print_address_description+0x73/0x280 [ 40.587513] [] kasan_report+0x275/0x360 [ 40.593110] [] ? sg_remove_request+0x103/0x120 [ 40.599322] [] __asan_report_load8_noabort+0x14/0x20 [ 40.606058] [] sg_remove_request+0x103/0x120 [ 40.612096] [] sg_finish_rem_req+0x295/0x340 [ 40.618131] [] sg_read+0xa1c/0x1440 [ 40.623382] [] ? sg_proc_seq_show_debug+0xd10/0xd10 [ 40.630023] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 40.637018] [] ? fasync_helper+0x37/0xb0 [ 40.642704] [] ? sg_proc_seq_show_debug+0xd10/0xd10 [ 40.649344] [] __vfs_read+0x103/0x670 [ 40.654781] [] ? default_llseek+0x290/0x290 [ 40.660726] [] ? fsnotify+0x86/0xf30 [ 40.666061] [] ? fsnotify+0xf30/0xf30 [ 40.671485] [] ? avc_policy_seqno+0x9/0x20 [ 40.677344] [] ? selinux_file_permission+0x82/0x460 [ 40.683981] [] ? security_file_permission+0x89/0x1e0 [ 40.690704] [] ? rw_verify_area+0xe5/0x2b0 [ 40.696574] [] vfs_read+0x11e/0x380 [ 40.701822] [] SyS_read+0xd9/0x1b0 [ 40.706984] [] ? vfs_copy_file_range+0x740/0x740 [ 40.713364] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 40.720186] [] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 40.726748] [] entry_SYSCALL_64_fastpath+0x23/0xe2 [ 40.733298] [ 40.734898] Allocated by task 0: [ 40.738236] (stack is not available) [ 40.741917] [ 40.743516] Freed by task 0: [ 40.746500] (stack is not available) [ 40.750181] [ 40.751781] The buggy address belongs to the object at ffff8801c7004100 [ 40.751781] which belongs to the cache fasync_cache of size 96 [ 40.766235] The buggy address is located 64 bytes inside of [ 40.766235] 96-byte region [ffff8801c7004100, ffff8801c7004160) [ 40.777905] The buggy address belongs to the page: [ 40.782808] page:ffffea00071c0100 count:1 mapcount:0 mapping: (null) index:0x0 [ 40.791034] flags: 0x8000000000000080(slab) [ 40.795321] page dumped because: kasan: bad access detected [ 40.800997] [ 40.802594] Memory state around the buggy address: [ 40.807496] ffff8801c7004000: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc [ 40.814831] ffff8801c7004080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 40.822173] >ffff8801c7004100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 40.829503] ^ [ 40.834922] ffff8801c7004180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 40.842250] ffff8801c7004200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 40.849580] ================================================================== [ 40.856913] Disabling lock debugging due to kernel taint [ 40.862447] Kernel panic - not syncing: panic_on_warn set ... [ 40.862447] [ 40.869796] CPU: 1 PID: 3343 Comm: syzkaller413484 Tainted: G B 4.9.76-gf0f6293 #12 [ 40.878693] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 40.888021] ffff8801cca1fa08 ffffffff81d93149 ffffffff84195c17 ffff8801cca1fae0 [ 40.896000] 0000000000000000 ffff8801c7004140 ffff8801c84e8238 ffff8801cca1fad0 [ 40.903972] ffffffff8142e371 0000000041b58ab3 ffffffff84189678 ffffffff8142e1b5 [ 40.911947] Call Trace: [ 40.914512] [] dump_stack+0xc1/0x128 [ 40.919848] [] panic+0x1bc/0x3a8 [ 40.924837] [] ? percpu_up_read_preempt_enable.constprop.53+0xd7/0xd7 [ 40.933050] [] ? preempt_schedule+0x25/0x30 [ 40.938992] [] ? ___preempt_schedule+0x16/0x18 [ 40.945200] [] kasan_end_report+0x50/0x50 [ 40.950972] [] kasan_report+0x167/0x360 [ 40.956569] [] ? sg_remove_request+0x103/0x120 [ 40.962773] [] __asan_report_load8_noabort+0x14/0x20 [ 40.969502] [] sg_remove_request+0x103/0x120 [ 40.975539] [] sg_finish_rem_req+0x295/0x340 [ 40.981573] [] sg_read+0xa1c/0x1440 [ 40.986849] [] ? sg_proc_seq_show_debug+0xd10/0xd10 [ 40.993499] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 41.000486] [] ? fasync_helper+0x37/0xb0 [ 41.006168] [] ? sg_proc_seq_show_debug+0xd10/0xd10 [ 41.012807] [] __vfs_read+0x103/0x670 [ 41.018229] [] ? default_llseek+0x290/0x290 [ 41.024173] [] ? fsnotify+0x86/0xf30 [ 41.029509] [] ? fsnotify+0xf30/0xf30 [ 41.034943] [] ? avc_policy_seqno+0x9/0x20 [ 41.040797] [] ? selinux_file_permission+0x82/0x460 [ 41.047523] [] ? security_file_permission+0x89/0x1e0 [ 41.054248] [] ? rw_verify_area+0xe5/0x2b0 [ 41.060104] [] vfs_read+0x11e/0x380 [ 41.065350] [] SyS_read+0xd9/0x1b0 [ 41.070509] [] ? vfs_copy_file_range+0x740/0x740 [ 41.076885] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 41.083699] [] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 41.091036] [] entry_SYSCALL_64_fastpath+0x23/0xe2 [ 41.098003] Dumping ftrace buffer: [ 41.101522] (ftrace buffer empty) [ 41.105218] Kernel Offset: disabled [ 41.108817] Rebooting in 86400 seconds..