[....] Starting enhanced syslogd: rsyslogd[ 13.809835] audit: type=1400 audit(1515601920.946:4): avc: denied { syslog } for pid=3177 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 '10.128.0.42' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 26.212152] ================================================================== [ 26.219565] BUG: KASAN: slab-out-of-bounds in sg_remove_request+0x103/0x120 [ 26.226637] Read of size 8 at addr ffff8801c9777140 by task syzkaller834750/3333 [ 26.234134] [ 26.235732] CPU: 1 PID: 3333 Comm: syzkaller834750 Not tainted 4.9.76-g9154940 #20 [ 26.243403] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 26.252734] ffff8801c7c7fa50 ffffffff81d93149 ffffea000725ddc0 ffff8801c9777140 [ 26.260702] 0000000000000000 ffff8801c9777140 ffff8801c8768238 ffff8801c7c7fa88 [ 26.268654] ffffffff8153cb43 ffff8801c9777140 0000000000000008 0000000000000000 [ 26.276609] Call Trace: [ 26.279165] [] dump_stack+0xc1/0x128 [ 26.284507] [] print_address_description+0x73/0x280 [ 26.291151] [] kasan_report+0x275/0x360 [ 26.296743] [] ? sg_remove_request+0x103/0x120 [ 26.302957] [] __asan_report_load8_noabort+0x14/0x20 [ 26.309681] [] sg_remove_request+0x103/0x120 [ 26.315707] [] sg_finish_rem_req+0x295/0x340 [ 26.321735] [] sg_read+0xa1c/0x1440 [ 26.326981] [] ? sg_proc_seq_show_debug+0xd10/0xd10 [ 26.333628] [] ? __raw_spin_lock_init+0x1c/0x100 [ 26.340023] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 26.346848] [] ? sg_proc_seq_show_debug+0xd10/0xd10 [ 26.353486] [] __vfs_read+0x103/0x670 [ 26.358904] [] ? default_llseek+0x290/0x290 [ 26.364845] [] ? fsnotify+0x86/0xf30 [ 26.370177] [] ? fsnotify+0xf30/0xf30 [ 26.375602] [] ? avc_policy_seqno+0x9/0x20 [ 26.381469] [] ? selinux_file_permission+0x82/0x460 [ 26.388103] [] ? security_file_permission+0x89/0x1e0 [ 26.394824] [] ? rw_verify_area+0xe5/0x2b0 [ 26.400680] [] vfs_read+0x11e/0x380 [ 26.405926] [] SyS_read+0xd9/0x1b0 [ 26.411089] [] ? vfs_copy_file_range+0x740/0x740 [ 26.417466] [] ? do_fast_syscall_32+0xcf/0x890 [ 26.423670] [] ? vfs_copy_file_range+0x740/0x740 [ 26.430045] [] do_fast_syscall_32+0x2f7/0x890 [ 26.436160] [] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 26.442794] [] entry_SYSENTER_compat+0x74/0x83 [ 26.449003] [ 26.450605] Allocated by task 0: [ 26.453942] (stack is not available) [ 26.457628] [ 26.459230] Freed by task 0: [ 26.462211] (stack is not available) [ 26.465888] [ 26.467494] The buggy address belongs to the object at ffff8801c9777100 [ 26.467494] which belongs to the cache fasync_cache of size 96 [ 26.480117] The buggy address is located 64 bytes inside of [ 26.480117] 96-byte region [ffff8801c9777100, ffff8801c9777160) [ 26.491781] The buggy address belongs to the page: [ 26.496687] page:ffffea000725ddc0 count:1 mapcount:0 mapping: (null) index:0x0 [ 26.504906] flags: 0x8000000000000080(slab) [ 26.509193] page dumped because: kasan: bad access detected [ 26.514868] [ 26.516460] Memory state around the buggy address: [ 26.521356] ffff8801c9777000: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc [ 26.528683] ffff8801c9777080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 26.536018] >ffff8801c9777100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 26.543343] ^ [ 26.548759] ffff8801c9777180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 26.556084] ffff8801c9777200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 26.563406] ================================================================== [ 26.570728] Disabling lock debugging due to kernel taint [ 26.576292] Kernel panic - not syncing: panic_on_warn set ... [ 26.576292] [ 26.583644] CPU: 1 PID: 3333 Comm: syzkaller834750 Tainted: G B 4.9.76-g9154940 #20 [ 26.592543] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 26.601888] ffff8801c7c7f9a8 ffffffff81d93149 ffffffff84195c17 ffff8801c7c7fa80 [ 26.609853] 0000000000000000 ffff8801c9777140 ffff8801c8768238 ffff8801c7c7fa70 [ 26.617812] ffffffff8142e371 0000000041b58ab3 ffffffff84189678 ffffffff8142e1b5 [ 26.625797] Call Trace: [ 26.628364] [] dump_stack+0xc1/0x128 [ 26.633708] [] panic+0x1bc/0x3a8 [ 26.638695] [] ? percpu_up_read_preempt_enable.constprop.53+0xd7/0xd7 [ 26.646902] [] ? preempt_schedule+0x25/0x30 [ 26.652849] [] ? ___preempt_schedule+0x16/0x18 [ 26.659052] [] kasan_end_report+0x50/0x50 [ 26.664816] [] kasan_report+0x167/0x360 [ 26.670405] [] ? sg_remove_request+0x103/0x120 [ 26.676604] [] __asan_report_load8_noabort+0x14/0x20 [ 26.683336] [] sg_remove_request+0x103/0x120 [ 26.689378] [] sg_finish_rem_req+0x295/0x340 [ 26.695402] [] sg_read+0xa1c/0x1440 [ 26.700650] [] ? sg_proc_seq_show_debug+0xd10/0xd10 [ 26.707286] [] ? __raw_spin_lock_init+0x1c/0x100 [ 26.713669] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 26.720482] [] ? sg_proc_seq_show_debug+0xd10/0xd10 [ 26.727117] [] __vfs_read+0x103/0x670 [ 26.732547] [] ? default_llseek+0x290/0x290 [ 26.738493] [] ? fsnotify+0x86/0xf30 [ 26.743821] [] ? fsnotify+0xf30/0xf30 [ 26.749237] [] ? avc_policy_seqno+0x9/0x20 [ 26.755088] [] ? selinux_file_permission+0x82/0x460 [ 26.761720] [] ? security_file_permission+0x89/0x1e0 [ 26.768441] [] ? rw_verify_area+0xe5/0x2b0 [ 26.774292] [] vfs_read+0x11e/0x380 [ 26.779533] [] SyS_read+0xd9/0x1b0 [ 26.784702] [] ? vfs_copy_file_range+0x740/0x740 [ 26.791077] [] ? do_fast_syscall_32+0xcf/0x890 [ 26.797290] [] ? vfs_copy_file_range+0x740/0x740 [ 26.803669] [] do_fast_syscall_32+0x2f7/0x890 [ 26.809807] [] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 26.816443] [] entry_SYSENTER_compat+0x74/0x83 [ 26.823085] Dumping ftrace buffer: [ 26.826598] (ftrace buffer empty) [ 26.830275] Kernel Offset: disabled [ 26.833869] Rebooting in 86400 seconds..