[....] Starting enhanced syslogd: rsyslogd[ 13.530612] audit: type=1400 audit(1515709362.719:4): avc: denied { syslog } for pid=3181 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 '10.128.15.230' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 27.217144] ================================================================== [ 27.224534] BUG: KASAN: slab-out-of-bounds in sg_remove_request+0x103/0x120 [ 27.231599] Read of size 8 at addr ffff8801c8e06140 by task syzkaller578732/3337 [ 27.239093] [ 27.240688] CPU: 1 PID: 3337 Comm: syzkaller578732 Not tainted 4.9.76-g9154940 #20 [ 27.248356] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 27.257675] ffff8801c865fa50 ffffffff81d93149 ffffea0007238180 ffff8801c8e06140 [ 27.265636] 0000000000000000 ffff8801c8e06140 ffff8801d6174438 ffff8801c865fa88 [ 27.273586] ffffffff8153cb43 ffff8801c8e06140 0000000000000008 0000000000000000 [ 27.281537] Call Trace: [ 27.284094] [] dump_stack+0xc1/0x128 [ 27.289426] [] print_address_description+0x73/0x280 [ 27.296055] [] kasan_report+0x275/0x360 [ 27.301643] [] ? sg_remove_request+0x103/0x120 [ 27.307838] [] __asan_report_load8_noabort+0x14/0x20 [ 27.314552] [] sg_remove_request+0x103/0x120 [ 27.320574] [] sg_finish_rem_req+0x295/0x340 [ 27.326596] [] sg_read+0xa1c/0x1440 [ 27.331837] [] ? sg_proc_seq_show_debug+0xd10/0xd10 [ 27.338468] [] ? __raw_spin_lock_init+0x1c/0x100 [ 27.344842] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 27.351647] [] ? sg_proc_seq_show_debug+0xd10/0xd10 [ 27.358277] [] __vfs_read+0x103/0x670 [ 27.363691] [] ? default_llseek+0x290/0x290 [ 27.369627] [] ? fsnotify+0x86/0xf30 [ 27.374952] [] ? fsnotify+0xf30/0xf30 [ 27.380376] [] ? avc_policy_seqno+0x9/0x20 [ 27.386226] [] ? selinux_file_permission+0x82/0x460 [ 27.392881] [] ? security_file_permission+0x89/0x1e0 [ 27.399606] [] ? rw_verify_area+0xe5/0x2b0 [ 27.405464] [] vfs_read+0x11e/0x380 [ 27.410713] [] SyS_read+0xd9/0x1b0 [ 27.415884] [] ? vfs_copy_file_range+0x740/0x740 [ 27.422269] [] ? do_fast_syscall_32+0xcf/0x890 [ 27.428466] [] ? vfs_copy_file_range+0x740/0x740 [ 27.434836] [] do_fast_syscall_32+0x2f7/0x890 [ 27.440947] [] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 27.447581] [] entry_SYSENTER_compat+0x74/0x83 [ 27.453775] [ 27.455369] Allocated by task 0: [ 27.458697] (stack is not available) [ 27.462373] [ 27.463963] Freed by task 0: [ 27.466941] (stack is not available) [ 27.470613] [ 27.472206] The buggy address belongs to the object at ffff8801c8e06100 [ 27.472206] which belongs to the cache fasync_cache of size 96 [ 27.485129] The buggy address is located 64 bytes inside of [ 27.485129] 96-byte region [ffff8801c8e06100, ffff8801c8e06160) [ 27.496794] The buggy address belongs to the page: [ 27.501690] page:ffffea0007238180 count:1 mapcount:0 mapping: (null) index:0x0 [ 27.509908] flags: 0x8000000000000080(slab) [ 27.514190] page dumped because: kasan: bad access detected [ 27.519861] [ 27.521452] Memory state around the buggy address: [ 27.526343] ffff8801c8e06000: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc [ 27.533667] ffff8801c8e06080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 27.540991] >ffff8801c8e06100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 27.548315] ^ [ 27.553739] ffff8801c8e06180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 27.561063] ffff8801c8e06200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 27.568384] ================================================================== [ 27.575706] Disabling lock debugging due to kernel taint [ 27.581214] Kernel panic - not syncing: panic_on_warn set ... [ 27.581214] [ 27.588579] CPU: 1 PID: 3337 Comm: syzkaller578732 Tainted: G B 4.9.76-g9154940 #20 [ 27.597465] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 27.606786] ffff8801c865f9a8 ffffffff81d93149 ffffffff84195c17 ffff8801c865fa80 [ 27.614746] 0000000000000000 ffff8801c8e06140 ffff8801d6174438 ffff8801c865fa70 [ 27.622699] ffffffff8142e371 0000000041b58ab3 ffffffff84189678 ffffffff8142e1b5 [ 27.630665] Call Trace: [ 27.633223] [] dump_stack+0xc1/0x128 [ 27.638551] [] panic+0x1bc/0x3a8 [ 27.643535] [] ? percpu_up_read_preempt_enable.constprop.53+0xd7/0xd7 [ 27.651733] [] ? preempt_schedule+0x25/0x30 [ 27.657668] [] ? ___preempt_schedule+0x16/0x18 [ 27.663868] [] kasan_end_report+0x50/0x50 [ 27.669641] [] kasan_report+0x167/0x360 [ 27.675240] [] ? sg_remove_request+0x103/0x120 [ 27.681443] [] __asan_report_load8_noabort+0x14/0x20 [ 27.688159] [] sg_remove_request+0x103/0x120 [ 27.694184] [] sg_finish_rem_req+0x295/0x340 [ 27.700207] [] sg_read+0xa1c/0x1440 [ 27.705458] [] ? sg_proc_seq_show_debug+0xd10/0xd10 [ 27.712100] [] ? __raw_spin_lock_init+0x1c/0x100 [ 27.718481] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 27.725285] [] ? sg_proc_seq_show_debug+0xd10/0xd10 [ 27.731916] [] __vfs_read+0x103/0x670 [ 27.737336] [] ? default_llseek+0x290/0x290 [ 27.743274] [] ? fsnotify+0x86/0xf30 [ 27.748601] [] ? fsnotify+0xf30/0xf30 [ 27.754031] [] ? avc_policy_seqno+0x9/0x20 [ 27.759911] [] ? selinux_file_permission+0x82/0x460 [ 27.766547] [] ? security_file_permission+0x89/0x1e0 [ 27.773268] [] ? rw_verify_area+0xe5/0x2b0 [ 27.779119] [] vfs_read+0x11e/0x380 [ 27.784373] [] SyS_read+0xd9/0x1b0 [ 27.789545] [] ? vfs_copy_file_range+0x740/0x740 [ 27.795922] [] ? do_fast_syscall_32+0xcf/0x890 [ 27.802135] [] ? vfs_copy_file_range+0x740/0x740 [ 27.808509] [] do_fast_syscall_32+0x2f7/0x890 [ 27.814622] [] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 27.821265] [] entry_SYSENTER_compat+0x74/0x83 [ 27.828000] Dumping ftrace buffer: [ 27.831517] (ftrace buffer empty) [ 27.835193] Kernel Offset: disabled [ 27.838802] Rebooting in 86400 seconds..