[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 67.489110][ T27] audit: type=1800 audit(1577204967.443:25): pid=9158 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 67.509422][ T27] audit: type=1800 audit(1577204967.443:26): pid=9158 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 67.577540][ T27] audit: type=1800 audit(1577204967.443:27): pid=9158 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="restorecond" dev="sda1" ino=2436 res=0 [....] Starting periodic command scheduler: cron[?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 '10.128.0.234' (ECDSA) to the list of known hosts. syzkaller login: [ 83.718148][ T9320] IPVS: ftp: loaded support on port[0] = 21 [ 83.720538][ T9316] IPVS: ftp: loaded support on port[0] = 21 [ 83.724972][ T9322] IPVS: ftp: loaded support on port[0] = 21 [ 83.738551][ T9318] IPVS: ftp: loaded support on port[0] = 21 [ 83.752446][ T9321] IPVS: ftp: loaded support on port[0] = 21 [ 83.763943][ T9319] IPVS: ftp: loaded support on port[0] = 21 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 84.242682][ T9345] ================================================================== [ 84.242735][ T9345] BUG: KASAN: slab-out-of-bounds in fbcon_get_font+0x2b2/0x5e0 [ 84.242747][ T9345] Read of size 5 at addr ffff8880a83f440c by task syz-executor898/9345 [ 84.242750][ T9345] [ 84.242767][ T9345] CPU: 0 PID: 9345 Comm: syz-executor898 Not tainted 5.5.0-rc2-next-20191220-syzkaller #0 [ 84.242776][ T9345] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 84.242782][ T9345] Call Trace: [ 84.242798][ T9345] dump_stack+0x197/0x210 [ 84.242813][ T9345] ? fbcon_get_font+0x2b2/0x5e0 [ 84.242834][ T9345] print_address_description.constprop.0.cold+0xd4/0x30b [ 84.242848][ T9345] ? fbcon_get_font+0x2b2/0x5e0 [ 84.242862][ T9345] ? fbcon_get_font+0x2b2/0x5e0 [ 84.242878][ T9345] __kasan_report.cold+0x1b/0x41 [ 84.242895][ T9345] ? fbcon_get_font+0x2b2/0x5e0 [ 84.242913][ T9345] kasan_report+0x12/0x20 [ 84.242928][ T9345] check_memory_region+0x134/0x1a0 [ 84.242942][ T9345] memcpy+0x24/0x50 [ 84.242959][ T9345] fbcon_get_font+0x2b2/0x5e0 [ 84.242979][ T9345] ? display_to_var+0x7e0/0x7e0 [ 84.242995][ T9345] con_font_op+0x20b/0x1270 [ 84.243013][ T9345] ? apparmor_cred_prepare+0x7b0/0x7b0 [ 84.243030][ T9345] ? con_write+0xd0/0xd0 [ 84.243055][ T9345] ? cap_capable+0x205/0x270 [ 84.243077][ T9345] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 84.243093][ T9345] ? security_capable+0x95/0xc0 [ 84.243114][ T9345] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 84.243131][ T9345] ? ns_capable_common+0x93/0x100 [ 84.243153][ T9345] vt_ioctl+0xd2e/0x26d0 [ 84.243172][ T9345] ? complete_change_console+0x3a0/0x3a0 [ 84.243195][ T9345] ? tomoyo_execute_permission+0x4a0/0x4a0 [ 84.243220][ T9345] ? __sanitizer_cov_trace_switch+0x49/0x80 [ 84.243244][ T9345] ? tty_jobctrl_ioctl+0x50/0xd40 [ 84.243260][ T9345] ? complete_change_console+0x3a0/0x3a0 [ 84.243275][ T9345] tty_ioctl+0xa37/0x14f0 [ 84.243292][ T9345] ? tty_vhangup+0x30/0x30 [ 84.243306][ T9345] ? __sanitizer_cov_trace_const_cmp2+0x18/0x20 [ 84.243322][ T9345] ? do_vfs_ioctl+0x11b/0x1340 [ 84.243342][ T9345] ? ioctl_file_clone+0x180/0x180 [ 84.243358][ T9345] ? __fget+0x37f/0x550 [ 84.243379][ T9345] ? do_dup2+0x4f0/0x4f0 [ 84.243397][ T9345] ? rcu_read_lock_sched_held+0x9c/0xd0 [ 84.243417][ T9345] ? tomoyo_file_ioctl+0x23/0x30 [ 84.243434][ T9345] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 84.243450][ T9345] ? security_file_ioctl+0x8d/0xc0 [ 84.243462][ T9345] ? tty_vhangup+0x30/0x30 [ 84.243480][ T9345] ksys_ioctl+0x123/0x180 [ 84.243499][ T9345] __x64_sys_ioctl+0x73/0xb0 [ 84.243519][ T9345] do_syscall_64+0xfa/0x790 [ 84.243538][ T9345] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 84.243549][ T9345] RIP: 0033:0x448a09 [ 84.243564][ T9345] Code: e8 1c e6 ff ff 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 8b 06 fc ff c3 66 2e 0f 1f 84 00 00 00 00 [ 84.243572][ T9345] RSP: 002b:00007ff8b0880ce8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 84.243586][ T9345] RAX: ffffffffffffffda RBX: 00000000006e49e8 RCX: 0000000000448a09 [ 84.243594][ T9345] RDX: 0000000020000140 RSI: 0000000000004b60 RDI: 0000000000000003 [ 84.243602][ T9345] RBP: 00000000006e49e0 R08: 0000000000000000 R09: 0000000000000000 [ 84.243611][ T9345] R10: 000000000000000e R11: 0000000000000246 R12: 00000000006e49ec [ 84.243620][ T9345] R13: 00007ffd4fecc4bf R14: 00007ff8b08819c0 R15: 20c49ba5e353f7cf [ 84.243640][ T9345] [ 84.243647][ T9345] Allocated by task 9333: [ 84.243660][ T9345] save_stack+0x23/0x90 [ 84.243674][ T9345] __kasan_kmalloc.constprop.0+0xcf/0xe0 [ 84.243686][ T9345] kasan_kmalloc+0x9/0x10 [ 84.243697][ T9345] __kmalloc+0x163/0x770 [ 84.243710][ T9345] fbcon_set_font+0x32d/0x860 [ 84.243723][ T9345] con_font_op+0xe30/0x1270 [ 84.243735][ T9345] vt_ioctl+0xd2e/0x26d0 [ 84.243745][ T9345] tty_ioctl+0xa37/0x14f0 [ 84.243757][ T9345] ksys_ioctl+0x123/0x180 [ 84.243770][ T9345] __x64_sys_ioctl+0x73/0xb0 [ 84.243783][ T9345] do_syscall_64+0xfa/0x790 [ 84.243796][ T9345] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 84.243800][ T9345] [ 84.243806][ T9345] Freed by task 0: [ 84.243810][ T9345] (stack is not available) [ 84.243814][ T9345] [ 84.243824][ T9345] The buggy address belongs to the object at ffff8880a83f4000 [ 84.243824][ T9345] which belongs to the cache kmalloc-2k of size 2048 [ 84.243836][ T9345] The buggy address is located 1036 bytes inside of [ 84.243836][ T9345] 2048-byte region [ffff8880a83f4000, ffff8880a83f4800) [ 84.243841][ T9345] The buggy address belongs to the page: [ 84.243854][ T9345] page:ffffea0002a0fd00 refcount:1 mapcount:0 mapping:ffff8880aa400e00 index:0x0 [ 84.243874][ T9345] raw: 00fffe0000000200 ffffea00028fd448 ffffea0002818c88 ffff8880aa400e00 [ 84.243890][ T9345] raw: 0000000000000000 ffff8880a83f4000 0000000100000001 0000000000000000 [ 84.243896][ T9345] page dumped because: kasan: bad access detected [ 84.243900][ T9345] [ 84.243904][ T9345] Memory state around the buggy address: [ 84.243916][ T9345] ffff8880a83f4300: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 84.243927][ T9345] ffff8880a83f4380: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 84.243939][ T9345] >ffff8880a83f4400: 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 84.243944][ T9345] ^ [ 84.243955][ T9345] ffff8880a83f4480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 84.243966][ T9345] ffff8880a83f4500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 84.243972][ T9345] ================================================================== [ 84.243977][ T9345] Disabling lock debugging due to kernel taint [ 84.244065][ T9345] Kernel panic - not syncing: panic_on_warn set ... [ 84.244080][ T9345] CPU: 0 PID: 9345 Comm: syz-executor898 Tainted: G B 5.5.0-rc2-next-20191220-syzkaller #0 [ 84.244088][ T9345] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 84.244092][ T9345] Call Trace: [ 84.244106][ T9345] dump_stack+0x197/0x210 [ 84.244122][ T9345] panic+0x2e3/0x75c [ 84.244135][ T9345] ? add_taint.cold+0x16/0x16 [ 84.244149][ T9345] ? fbcon_get_font+0x2b2/0x5e0 [ 84.244163][ T9345] ? preempt_schedule+0x4b/0x60 [ 84.244178][ T9345] ? ___preempt_schedule+0x16/0x18 [ 84.244193][ T9345] ? trace_hardirqs_on+0x5e/0x240 [ 84.244208][ T9345] ? fbcon_get_font+0x2b2/0x5e0 [ 84.244222][ T9345] end_report+0x47/0x4f [ 84.244240][ T9345] ? fbcon_get_font+0x2b2/0x5e0 [ 84.244252][ T9345] __kasan_report.cold+0xe/0x41 [ 84.244267][ T9345] ? fbcon_get_font+0x2b2/0x5e0 [ 84.244281][ T9345] kasan_report+0x12/0x20 [ 84.244295][ T9345] check_memory_region+0x134/0x1a0 [ 84.244307][ T9345] memcpy+0x24/0x50 [ 84.244321][ T9345] fbcon_get_font+0x2b2/0x5e0 [ 84.244334][ T9345] ? display_to_var+0x7e0/0x7e0 [ 84.244347][ T9345] con_font_op+0x20b/0x1270 [ 84.244363][ T9345] ? apparmor_cred_prepare+0x7b0/0x7b0 [ 84.244377][ T9345] ? con_write+0xd0/0xd0 [ 84.244391][ T9345] ? cap_capable+0x205/0x270 [ 84.244408][ T9345] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 84.244420][ T9345] ? security_capable+0x95/0xc0 [ 84.244434][ T9345] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 84.244447][ T9345] ? ns_capable_common+0x93/0x100 [ 84.244461][ T9345] vt_ioctl+0xd2e/0x26d0 [ 84.244472][ T9345] ? complete_change_console+0x3a0/0x3a0 [ 84.244482][ T9345] ? tomoyo_execute_permission+0x4a0/0x4a0 [ 84.244492][ T9345] ? __sanitizer_cov_trace_switch+0x49/0x80 [ 84.244501][ T9345] ? tty_jobctrl_ioctl+0x50/0xd40 [ 84.244509][ T9345] ? complete_change_console+0x3a0/0x3a0 [ 84.244516][ T9345] tty_ioctl+0xa37/0x14f0 [ 84.244523][ T9345] ? tty_vhangup+0x30/0x30 [ 84.244531][ T9345] ? __sanitizer_cov_trace_const_cmp2+0x18/0x20 [ 84.244538][ T9345] ? do_vfs_ioctl+0x11b/0x1340 [ 84.244547][ T9345] ? ioctl_file_clone+0x180/0x180 [ 84.244554][ T9345] ? __fget+0x37f/0x550 [ 84.244563][ T9345] ? do_dup2+0x4f0/0x4f0 [ 84.244571][ T9345] ? rcu_read_lock_sched_held+0x9c/0xd0 [ 84.244580][ T9345] ? tomoyo_file_ioctl+0x23/0x30 [ 84.244588][ T9345] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 84.244596][ T9345] ? security_file_ioctl+0x8d/0xc0 [ 84.244602][ T9345] ? tty_vhangup+0x30/0x30 [ 84.244609][ T9345] ksys_ioctl+0x123/0x180 [ 84.244617][ T9345] __x64_sys_ioctl+0x73/0xb0 [ 84.244626][ T9345] do_syscall_64+0xfa/0x790 [ 84.244634][ T9345] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 84.244639][ T9345] RIP: 0033:0x448a09 [ 84.244647][ T9345] Code: e8 1c e6 ff ff 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 8b 06 fc ff c3 66 2e 0f 1f 84 00 00 00 00 [ 84.244651][ T9345] RSP: 002b:00007ff8b0880ce8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 84.244658][ T9345] RAX: ffffffffffffffda RBX: 00000000006e49e8 RCX: 0000000000448a09 [ 84.244662][ T9345] RDX: 0000000020000140 RSI: 0000000000004b60 RDI: 0000000000000003 [ 84.244666][ T9345] RBP: 00000000006e49e0 R08: 0000000000000000 R09: 0000000000000000 [ 84.244670][ T9345] R10: 000000000000000e R11: 0000000000000246 R12: 00000000006e49ec [ 84.244674][ T9345] R13: 00007ffd4fecc4bf R14: 00007ff8b08819c0 R15: 20c49ba5e353f7cf [ 84.246065][ T9345] Kernel Offset: disabled