[....] Starting enhanced syslogd: rsyslogd[ 11.042777] audit: type=1400 audit(1515290076.522:4): avc: denied { syslog } for pid=3175 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 '10.128.0.39' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 19.298014] ================================================================== [ 19.299129] BUG: KASAN: slab-out-of-bounds in sg_remove_request+0x103/0x120 [ 19.300152] Read of size 8 at addr ffff8801ccaaa140 by task syzkaller955319/3323 [ 19.301136] [ 19.301391] CPU: 0 PID: 3323 Comm: syzkaller955319 Not tainted 4.9.75-g06fe41f #16 [ 19.302425] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 19.303662] ffff8801c94bfa50 ffffffff81d93049 ffffea000732aa80 ffff8801ccaaa140 [ 19.304854] 0000000000000000 ffff8801ccaaa140 ffff8801c93e4438 ffff8801c94bfa88 [ 19.305985] ffffffff8153ca53 ffff8801ccaaa140 0000000000000008 0000000000000000 [ 19.307115] Call Trace: [ 19.307470] [] dump_stack+0xc1/0x128 [ 19.308203] [] print_address_description+0x73/0x280 [ 19.309110] [] kasan_report+0x275/0x360 [ 19.309868] [] ? sg_remove_request+0x103/0x120 [ 19.310688] [] __asan_report_load8_noabort+0x14/0x20 [ 19.311586] [] sg_remove_request+0x103/0x120 [ 19.312383] [] sg_finish_rem_req+0x295/0x340 [ 19.313210] [] sg_read+0xa1c/0x1440 [ 19.313908] [] ? sg_proc_seq_show_debug+0xd10/0xd10 [ 19.314783] [] ? __raw_spin_lock_init+0x1c/0x100 [ 19.315626] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 19.316556] [] ? sg_proc_seq_show_debug+0xd10/0xd10 [ 19.317461] [] __vfs_read+0x103/0x670 [ 19.318364] [] ? default_llseek+0x290/0x290 [ 19.324300] [] ? fsnotify+0x86/0xf30 [ 19.329629] [] ? fsnotify+0xf30/0xf30 [ 19.335045] [] ? avc_policy_seqno+0x9/0x20 [ 19.340906] [] ? selinux_file_permission+0x82/0x460 [ 19.347539] [] ? security_file_permission+0x89/0x1e0 [ 19.354259] [] ? rw_verify_area+0xe5/0x2b0 [ 19.360107] [] vfs_read+0x11e/0x380 [ 19.365349] [] SyS_read+0xd9/0x1b0 [ 19.370502] [] ? vfs_copy_file_range+0x740/0x740 [ 19.376873] [] ? do_fast_syscall_32+0xcf/0x890 [ 19.383070] [] ? vfs_copy_file_range+0x740/0x740 [ 19.389438] [] do_fast_syscall_32+0x2f7/0x890 [ 19.395546] [] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 19.402923] [] entry_SYSENTER_compat+0x74/0x83 [ 19.409118] [ 19.410712] Allocated by task 0: [ 19.414039] (stack is not available) [ 19.417714] [ 19.419306] Freed by task 0: [ 19.422287] (stack is not available) [ 19.425963] [ 19.427556] The buggy address belongs to the object at ffff8801ccaaa100 [ 19.427556] which belongs to the cache fasync_cache of size 96 [ 19.440175] The buggy address is located 64 bytes inside of [ 19.440175] 96-byte region [ffff8801ccaaa100, ffff8801ccaaa160) [ 19.451838] The buggy address belongs to the page: [ 19.456735] page:ffffea000732aa80 count:1 mapcount:0 mapping: (null) index:0x0 [ 19.464955] flags: 0x8000000000000080(slab) [ 19.469237] page dumped because: kasan: bad access detected [ 19.474922] [ 19.476514] Memory state around the buggy address: [ 19.481415] ffff8801ccaaa000: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc [ 19.488748] ffff8801ccaaa080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 19.496073] >ffff8801ccaaa100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 19.503394] ^ [ 19.508816] ffff8801ccaaa180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 19.516149] ffff8801ccaaa200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 19.523470] ================================================================== [ 19.530790] Disabling lock debugging due to kernel taint [ 19.536521] Kernel panic - not syncing: panic_on_warn set ... [ 19.536521] [ 19.543869] CPU: 0 PID: 3323 Comm: syzkaller955319 Tainted: G B 4.9.75-g06fe41f #16 [ 19.552758] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 19.562078] ffff8801c94bf9a8 ffffffff81d93049 ffffffff84195be7 ffff8801c94bfa80 [ 19.570026] 0000000000000000 ffff8801ccaaa140 ffff8801c93e4438 ffff8801c94bfa70 [ 19.577975] ffffffff8142e281 0000000041b58ab3 ffffffff84189648 ffffffff8142e0c5 [ 19.585926] Call Trace: [ 19.588480] [] dump_stack+0xc1/0x128 [ 19.593827] [] panic+0x1bc/0x3a8 [ 19.598818] [] ? percpu_up_read_preempt_enable.constprop.53+0xd7/0xd7 [ 19.607022] [] ? preempt_schedule+0x25/0x30 [ 19.612961] [] ? ___preempt_schedule+0x16/0x18 [ 19.619168] [] kasan_end_report+0x50/0x50 [ 19.624939] [] kasan_report+0x167/0x360 [ 19.630536] [] ? sg_remove_request+0x103/0x120 [ 19.636741] [] __asan_report_load8_noabort+0x14/0x20 [ 19.643459] [] sg_remove_request+0x103/0x120 [ 19.649481] [] sg_finish_rem_req+0x295/0x340 [ 19.655501] [] sg_read+0xa1c/0x1440 [ 19.660740] [] ? sg_proc_seq_show_debug+0xd10/0xd10 [ 19.667383] [] ? __raw_spin_lock_init+0x1c/0x100 [ 19.673756] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 19.680559] [] ? sg_proc_seq_show_debug+0xd10/0xd10 [ 19.687191] [] __vfs_read+0x103/0x670 [ 19.692608] [] ? default_llseek+0x290/0x290 [ 19.698556] [] ? fsnotify+0x86/0xf30 [ 19.703884] [] ? fsnotify+0xf30/0xf30 [ 19.709300] [] ? avc_policy_seqno+0x9/0x20 [ 19.715149] [] ? selinux_file_permission+0x82/0x460 [ 19.721788] [] ? security_file_permission+0x89/0x1e0 [ 19.728504] [] ? rw_verify_area+0xe5/0x2b0 [ 19.734352] [] vfs_read+0x11e/0x380 [ 19.739595] [] SyS_read+0xd9/0x1b0 [ 19.744751] [] ? vfs_copy_file_range+0x740/0x740 [ 19.751120] [] ? do_fast_syscall_32+0xcf/0x890 [ 19.757318] [] ? vfs_copy_file_range+0x740/0x740 [ 19.763701] [] do_fast_syscall_32+0x2f7/0x890 [ 19.769811] [] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 19.776454] [] entry_SYSENTER_compat+0x74/0x83 [ 19.783085] Dumping ftrace buffer: [ 19.786598] (ftrace buffer empty) [ 19.790281] Kernel Offset: disabled [ 19.793882] Rebooting in 86400 seconds..