[....] Starting enhanced syslogd: rsyslogd[ 13.295102] audit: type=1400 audit(1520807664.680:4): avc: denied { syslog } for pid=3646 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 '10.128.0.50' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 24.743018] ================================================================== [ 24.750388] BUG: KASAN: slab-out-of-bounds in sg_remove_request+0x103/0x120 [ 24.757455] Read of size 8 at addr ffff8801c1c62140 by task syzkaller441555/3802 [ 24.764953] [ 24.766549] CPU: 0 PID: 3802 Comm: syzkaller441555 Not tainted 4.9.87-ga290494 #53 [ 24.774220] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 24.783540] ffff8801b05e7a60 ffffffff81d95a19 ffffea0007071880 ffff8801c1c62140 [ 24.791502] 0000000000000000 ffff8801c1c62140 ffff8801b053c438 ffff8801b05e7a98 [ 24.799463] ffffffff8153e333 ffff8801c1c62140 0000000000000008 0000000000000000 [ 24.807421] Call Trace: [ 24.809976] [] dump_stack+0xc1/0x128 [ 24.815309] [] print_address_description+0x73/0x280 [ 24.821939] [] kasan_report+0x275/0x360 [ 24.827530] [] ? sg_remove_request+0x103/0x120 [ 24.833729] [] __asan_report_load8_noabort+0x14/0x20 [ 24.840448] [] sg_remove_request+0x103/0x120 [ 24.846470] [] sg_finish_rem_req+0x295/0x340 [ 24.852496] [] sg_read+0xa16/0x1440 [ 24.857738] [] ? sg_proc_seq_show_debug+0xd90/0xd90 [ 24.864368] [] ? new_slab+0x318/0x420 [ 24.869788] [] ? fasync_helper+0x37/0xb0 [ 24.875463] [] ? sg_proc_seq_show_debug+0xd90/0xd90 [ 24.882098] [] __vfs_read+0x103/0x670 [ 24.887513] [] ? default_llseek+0x290/0x290 [ 24.893450] [] ? fsnotify+0x86/0xf30 [ 24.898778] [] ? fsnotify+0xf30/0xf30 [ 24.904196] [] ? avc_policy_seqno+0x9/0x20 [ 24.910049] [] ? selinux_file_permission+0x82/0x460 [ 24.916683] [] ? security_file_permission+0x89/0x1e0 [ 24.923401] [] ? rw_verify_area+0xe5/0x2b0 [ 24.929251] [] vfs_read+0x11e/0x380 [ 24.934492] [] SyS_read+0xd9/0x1b0 [ 24.939647] [] ? vfs_copy_file_range+0x740/0x740 [ 24.946021] [] ? do_syscall_64+0x48/0x490 [ 24.951786] [] ? vfs_copy_file_range+0x740/0x740 [ 24.958156] [] do_syscall_64+0x1a4/0x490 [ 24.963835] [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 24.970726] [ 24.972323] Allocated by task 0: [ 24.975650] (stack is not available) [ 24.979325] [ 24.980919] Freed by task 0: [ 24.983904] (stack is not available) [ 24.987578] [ 24.989176] The buggy address belongs to the object at ffff8801c1c62100 [ 24.989176] which belongs to the cache fasync_cache of size 96 [ 25.001797] The buggy address is located 64 bytes inside of [ 25.001797] 96-byte region [ffff8801c1c62100, ffff8801c1c62160) [ 25.013460] The buggy address belongs to the page: [ 25.018358] page:ffffea0007071880 count:1 mapcount:0 mapping: (null) index:0x0 [ 25.026582] flags: 0x8000000000000080(slab) [ 25.030869] page dumped because: kasan: bad access detected [ 25.036544] [ 25.038136] Memory state around the buggy address: [ 25.043033] ffff8801c1c62000: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc [ 25.050360] ffff8801c1c62080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 25.057687] >ffff8801c1c62100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 25.065011] ^ [ 25.070424] ffff8801c1c62180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 25.077747] ffff8801c1c62200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 25.085071] ================================================================== [ 25.092393] Disabling lock debugging due to kernel taint [ 25.098196] Kernel panic - not syncing: panic_on_warn set ... [ 25.098196] [ 25.105543] CPU: 0 PID: 3802 Comm: syzkaller441555 Tainted: G B 4.9.87-ga290494 #53 [ 25.114433] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 25.123755] ffff8801b05e79b8 ffffffff81d95a19 ffffffff84197bf7 ffff8801b05e7a90 [ 25.131721] 0000000000000000 ffff8801c1c62140 ffff8801b053c438 ffff8801b05e7a80 [ 25.139682] ffffffff8142f7e1 0000000041b58ab3 ffffffff8418b658 ffffffff8142f625 [ 25.147643] Call Trace: [ 25.150202] [] dump_stack+0xc1/0x128 [ 25.155536] [] panic+0x1bc/0x3a8 [ 25.160523] [] ? percpu_up_read_preempt_enable.constprop.53+0xd7/0xd7 [ 25.168718] [] ? preempt_schedule+0x25/0x30 [ 25.174656] [] ? ___preempt_schedule+0x16/0x18 [ 25.180858] [] kasan_end_report+0x50/0x50 [ 25.186619] [] kasan_report+0x167/0x360 [ 25.192213] [] ? sg_remove_request+0x103/0x120 [ 25.198412] [] __asan_report_load8_noabort+0x14/0x20 [ 25.205130] [] sg_remove_request+0x103/0x120 [ 25.211156] [] sg_finish_rem_req+0x295/0x340 [ 25.217178] [] sg_read+0xa16/0x1440 [ 25.222422] [] ? sg_proc_seq_show_debug+0xd90/0xd90 [ 25.229057] [] ? new_slab+0x318/0x420 [ 25.234476] [] ? fasync_helper+0x37/0xb0 [ 25.240152] [] ? sg_proc_seq_show_debug+0xd90/0xd90 [ 25.246783] [] __vfs_read+0x103/0x670 [ 25.252201] [] ? default_llseek+0x290/0x290 [ 25.258138] [] ? fsnotify+0x86/0xf30 [ 25.263465] [] ? fsnotify+0xf30/0xf30 [ 25.268881] [] ? avc_policy_seqno+0x9/0x20 [ 25.274732] [] ? selinux_file_permission+0x82/0x460 [ 25.281364] [] ? security_file_permission+0x89/0x1e0 [ 25.288083] [] ? rw_verify_area+0xe5/0x2b0 [ 25.293937] [] vfs_read+0x11e/0x380 [ 25.299182] [] SyS_read+0xd9/0x1b0 [ 25.304337] [] ? vfs_copy_file_range+0x740/0x740 [ 25.310709] [] ? do_syscall_64+0x48/0x490 [ 25.316473] [] ? vfs_copy_file_range+0x740/0x740 [ 25.322843] [] do_syscall_64+0x1a4/0x490 [ 25.328523] [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 25.335824] Dumping ftrace buffer: [ 25.339334] (ftrace buffer empty) [ 25.343012] Kernel Offset: disabled [ 25.346605] Rebooting in 86400 seconds..