[....] Starting enhanced syslogd: rsyslogd[ 13.652211] audit: type=1400 audit(1515882172.254:4): avc: denied { syslog } for pid=3176 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 '10.128.0.17' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 30.408051] ================================================================== [ 30.415454] BUG: KASAN: slab-out-of-bounds in sg_remove_request+0x103/0x120 [ 30.422521] Read of size 8 at addr ffff8801c96f0140 by task syzkaller092547/3333 [ 30.430035] [ 30.431642] CPU: 1 PID: 3333 Comm: syzkaller092547 Not tainted 4.9.76-g8e170a5 #21 [ 30.439318] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 30.448640] ffff8801c8597940 ffffffff81d93149 ffffea000725bc00 ffff8801c96f0140 [ 30.456590] 0000000000000000 ffff8801c96f0140 ffff8801c87f0238 ffff8801c8597978 [ 30.464541] ffffffff8153cb43 ffff8801c96f0140 0000000000000008 0000000000000000 [ 30.472489] Call Trace: [ 30.475047] [] dump_stack+0xc1/0x128 [ 30.480379] [] print_address_description+0x73/0x280 [ 30.487097] [] kasan_report+0x275/0x360 [ 30.492688] [] ? sg_remove_request+0x103/0x120 [ 30.498900] [] __asan_report_load8_noabort+0x14/0x20 [ 30.505623] [] sg_remove_request+0x103/0x120 [ 30.511647] [] sg_finish_rem_req+0x295/0x340 [ 30.517672] [] sg_read+0xa1c/0x1440 [ 30.522915] [] ? sg_proc_seq_show_debug+0xd10/0xd10 [ 30.529547] [] ? fsnotify+0xf30/0xf30 [ 30.534967] [] ? avc_policy_seqno+0x9/0x20 [ 30.540819] [] do_loop_readv_writev.part.17+0x141/0x1e0 [ 30.547799] [] ? security_file_permission+0x89/0x1e0 [ 30.554517] [] ? sg_proc_seq_show_debug+0xd10/0xd10 [ 30.561148] [] ? sg_proc_seq_show_debug+0xd10/0xd10 [ 30.567783] [] compat_do_readv_writev+0x522/0x760 [ 30.574245] [] ? do_pwritev+0x1a0/0x1a0 [ 30.579848] [] ? _raw_spin_unlock+0x2c/0x50 [ 30.585793] [] ? handle_mm_fault+0x6ee/0x2530 [ 30.591906] [] ? fasync_helper+0x7a/0xb0 [ 30.597583] [] ? __pmd_alloc+0x410/0x410 [ 30.603260] [] compat_readv+0xe3/0x150 [ 30.608766] [] do_compat_readv+0xf4/0x1d0 [ 30.614535] [] ? compat_readv+0x150/0x150 [ 30.620301] [] compat_SyS_readv+0x26/0x30 [ 30.626064] [] ? SyS_pwritev2+0x80/0x80 [ 30.631661] [] do_fast_syscall_32+0x2f7/0x890 [ 30.637779] [] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 30.644411] [] entry_SYSENTER_compat+0x74/0x83 [ 30.650607] [ 30.652199] Allocated by task 0: [ 30.655527] (stack is not available) [ 30.659202] [ 30.660796] Freed by task 0: [ 30.663776] (stack is not available) [ 30.667450] [ 30.669043] The buggy address belongs to the object at ffff8801c96f0100 [ 30.669043] which belongs to the cache fasync_cache of size 96 [ 30.681755] The buggy address is located 64 bytes inside of [ 30.681755] 96-byte region [ffff8801c96f0100, ffff8801c96f0160) [ 30.693429] The buggy address belongs to the page: [ 30.698327] page:ffffea000725bc00 count:1 mapcount:0 mapping: (null) index:0x0 [ 30.706556] flags: 0x8000000000000080(slab) [ 30.710841] page dumped because: kasan: bad access detected [ 30.716513] [ 30.718106] Memory state around the buggy address: [ 30.723008] ffff8801c96f0000: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc [ 30.730334] ffff8801c96f0080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 30.737660] >ffff8801c96f0100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 30.744986] ^ [ 30.750407] ffff8801c96f0180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 30.757733] ffff8801c96f0200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 30.765062] ================================================================== [ 30.772383] Disabling lock debugging due to kernel taint [ 30.777983] Kernel panic - not syncing: panic_on_warn set ... [ 30.777983] [ 30.785322] CPU: 1 PID: 3333 Comm: syzkaller092547 Tainted: G B 4.9.76-g8e170a5 #21 [ 30.794218] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 30.803540] ffff8801c8597898 ffffffff81d93149 ffffffff84195c17 ffff8801c8597970 [ 30.811510] 0000000000000000 ffff8801c96f0140 ffff8801c87f0238 ffff8801c8597960 [ 30.819559] ffffffff8142e371 0000000041b58ab3 ffffffff84189678 ffffffff8142e1b5 [ 30.827510] Call Trace: [ 30.830073] [] dump_stack+0xc1/0x128 [ 30.835414] [] panic+0x1bc/0x3a8 [ 30.840405] [] ? percpu_up_read_preempt_enable.constprop.53+0xd7/0xd7 [ 30.848603] [] ? preempt_schedule+0x25/0x30 [ 30.854547] [] ? ___preempt_schedule+0x16/0x18 [ 30.860746] [] kasan_end_report+0x50/0x50 [ 30.866510] [] kasan_report+0x167/0x360 [ 30.872099] [] ? sg_remove_request+0x103/0x120 [ 30.878298] [] __asan_report_load8_noabort+0x14/0x20 [ 30.885018] [] sg_remove_request+0x103/0x120 [ 30.891043] [] sg_finish_rem_req+0x295/0x340 [ 30.897987] [] sg_read+0xa1c/0x1440 [ 30.903230] [] ? sg_proc_seq_show_debug+0xd10/0xd10 [ 30.909860] [] ? fsnotify+0xf30/0xf30 [ 30.915290] [] ? avc_policy_seqno+0x9/0x20 [ 30.921139] [] do_loop_readv_writev.part.17+0x141/0x1e0 [ 30.928119] [] ? security_file_permission+0x89/0x1e0 [ 30.934840] [] ? sg_proc_seq_show_debug+0xd10/0xd10 [ 30.941478] [] ? sg_proc_seq_show_debug+0xd10/0xd10 [ 30.948111] [] compat_do_readv_writev+0x522/0x760 [ 30.954571] [] ? do_pwritev+0x1a0/0x1a0 [ 30.960162] [] ? _raw_spin_unlock+0x2c/0x50 [ 30.966099] [] ? handle_mm_fault+0x6ee/0x2530 [ 30.972208] [] ? fasync_helper+0x7a/0xb0 [ 30.977885] [] ? __pmd_alloc+0x410/0x410 [ 30.983566] [] compat_readv+0xe3/0x150 [ 30.989077] [] do_compat_readv+0xf4/0x1d0 [ 30.994849] [] ? compat_readv+0x150/0x150 [ 31.000616] [] compat_SyS_readv+0x26/0x30 [ 31.006388] [] ? SyS_pwritev2+0x80/0x80 [ 31.011978] [] do_fast_syscall_32+0x2f7/0x890 [ 31.018089] [] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 31.024721] [] entry_SYSENTER_compat+0x74/0x83 [ 31.031333] Dumping ftrace buffer: [ 31.034842] (ftrace buffer empty) [ 31.038517] Kernel Offset: disabled [ 31.042110] Rebooting in 86400 seconds..