[....] Starting enhanced syslogd: rsyslogd[ 10.738558] audit: type=1400 audit(1515364182.875:4): avc: denied { syslog } for pid=3172 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 '10.128.15.204' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 20.189362] ================================================================== [ 20.190402] BUG: KASAN: slab-out-of-bounds in sg_remove_request+0x103/0x120 [ 20.191349] Read of size 8 at addr ffff8801c8a8f140 by task syzkaller587701/3323 [ 20.192343] [ 20.192573] CPU: 0 PID: 3323 Comm: syzkaller587701 Not tainted 4.9.75-g5f5e5d4 #17 [ 20.193608] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 20.194825] ffff8801c8bafa50 ffffffff81d93049 ffffea000722a3c0 ffff8801c8a8f140 [ 20.195965] 0000000000000000 ffff8801c8a8f140 ffff8801c8540238 ffff8801c8bafa88 [ 20.197087] ffffffff8153ca53 ffff8801c8a8f140 0000000000000008 0000000000000000 [ 20.198251] Call Trace: [ 20.198612] [] dump_stack+0xc1/0x128 [ 20.199329] [] print_address_description+0x73/0x280 [ 20.200203] [] kasan_report+0x275/0x360 [ 20.200945] [] ? sg_remove_request+0x103/0x120 [ 20.201777] [] __asan_report_load8_noabort+0x14/0x20 [ 20.202661] [] sg_remove_request+0x103/0x120 [ 20.203457] [] sg_finish_rem_req+0x295/0x340 [ 20.204265] [] sg_read+0xa1c/0x1440 [ 20.204961] [] ? sg_proc_seq_show_debug+0xd10/0xd10 [ 20.205837] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 20.206766] [] ? sg_proc_seq_show_debug+0xd10/0xd10 [ 20.207659] [] __vfs_read+0x103/0x670 [ 20.209234] [] ? default_llseek+0x290/0x290 [ 20.210036] [] ? fsnotify+0x86/0xf30 [ 20.215362] [] ? fsnotify+0xf30/0xf30 [ 20.220778] [] ? avc_policy_seqno+0x9/0x20 [ 20.226637] [] ? selinux_file_permission+0x82/0x460 [ 20.233357] [] ? security_file_permission+0x89/0x1e0 [ 20.240074] [] ? rw_verify_area+0xe5/0x2b0 [ 20.245923] [] vfs_read+0x11e/0x380 [ 20.251163] [] SyS_read+0xd9/0x1b0 [ 20.256317] [] ? vfs_copy_file_range+0x740/0x740 [ 20.262686] [] ? do_fast_syscall_32+0xcf/0x890 [ 20.268885] [] ? vfs_copy_file_range+0x740/0x740 [ 20.275253] [] do_fast_syscall_32+0x2f7/0x890 [ 20.281362] [] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 20.287995] [] entry_SYSENTER_compat+0x74/0x83 [ 20.294189] [ 20.295785] Allocated by task 0: [ 20.299113] (stack is not available) [ 20.302792] [ 20.304382] Freed by task 0: [ 20.307359] (stack is not available) [ 20.311032] [ 20.312626] The buggy address belongs to the object at ffff8801c8a8f100 [ 20.312626] which belongs to the cache fasync_cache of size 96 [ 20.325252] The buggy address is located 64 bytes inside of [ 20.325252] 96-byte region [ffff8801c8a8f100, ffff8801c8a8f160) [ 20.336915] The buggy address belongs to the page: [ 20.341811] page:ffffea000722a3c0 count:1 mapcount:0 mapping: (null) index:0x0 [ 20.350046] flags: 0x8000000000000080(slab) [ 20.354329] page dumped because: kasan: bad access detected [ 20.360010] [ 20.361603] Memory state around the buggy address: [ 20.366495] ffff8801c8a8f000: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc [ 20.373821] ffff8801c8a8f080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 20.381143] >ffff8801c8a8f100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 20.388467] ^ [ 20.393882] ffff8801c8a8f180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 20.401205] ffff8801c8a8f200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 20.408527] ================================================================== [ 20.415847] Disabling lock debugging due to kernel taint [ 20.421570] Kernel panic - not syncing: panic_on_warn set ... [ 20.421570] [ 20.428917] CPU: 0 PID: 3323 Comm: syzkaller587701 Tainted: G B 4.9.75-g5f5e5d4 #17 [ 20.437804] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 20.447128] ffff8801c8baf9a8 ffffffff81d93049 ffffffff84195be7 ffff8801c8bafa80 [ 20.455085] 0000000000000000 ffff8801c8a8f140 ffff8801c8540238 ffff8801c8bafa70 [ 20.463038] ffffffff8142e281 0000000041b58ab3 ffffffff84189648 ffffffff8142e0c5 [ 20.470997] Call Trace: [ 20.473558] [] dump_stack+0xc1/0x128 [ 20.478894] [] panic+0x1bc/0x3a8 [ 20.483876] [] ? percpu_up_read_preempt_enable.constprop.53+0xd7/0xd7 [ 20.492071] [] ? preempt_schedule+0x25/0x30 [ 20.498007] [] ? ___preempt_schedule+0x16/0x18 [ 20.504209] [] kasan_end_report+0x50/0x50 [ 20.509972] [] kasan_report+0x167/0x360 [ 20.515568] [] ? sg_remove_request+0x103/0x120 [ 20.521767] [] __asan_report_load8_noabort+0x14/0x20 [ 20.528483] [] sg_remove_request+0x103/0x120 [ 20.534505] [] sg_finish_rem_req+0x295/0x340 [ 20.540527] [] sg_read+0xa1c/0x1440 [ 20.545769] [] ? sg_proc_seq_show_debug+0xd10/0xd10 [ 20.552408] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 20.559390] [] ? sg_proc_seq_show_debug+0xd10/0xd10 [ 20.566021] [] __vfs_read+0x103/0x670 [ 20.571438] [] ? default_llseek+0x290/0x290 [ 20.577389] [] ? fsnotify+0x86/0xf30 [ 20.582716] [] ? fsnotify+0xf30/0xf30 [ 20.588132] [] ? avc_policy_seqno+0x9/0x20 [ 20.593981] [] ? selinux_file_permission+0x82/0x460 [ 20.600610] [] ? security_file_permission+0x89/0x1e0 [ 20.607329] [] ? rw_verify_area+0xe5/0x2b0 [ 20.613186] [] vfs_read+0x11e/0x380 [ 20.618427] [] SyS_read+0xd9/0x1b0 [ 20.623590] [] ? vfs_copy_file_range+0x740/0x740 [ 20.629961] [] ? do_fast_syscall_32+0xcf/0x890 [ 20.636158] [] ? vfs_copy_file_range+0x740/0x740 [ 20.642527] [] do_fast_syscall_32+0x2f7/0x890 [ 20.648637] [] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 20.655275] [] entry_SYSENTER_compat+0x74/0x83 [ 20.661932] Dumping ftrace buffer: [ 20.665439] (ftrace buffer empty) [ 20.669117] Kernel Offset: disabled [ 20.672708] Rebooting in 86400 seconds..