[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 62.936324][ T27] audit: type=1800 audit(1575904600.363:25): pid=9031 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 62.956443][ T27] audit: type=1800 audit(1575904600.373:26): pid=9031 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 62.978473][ T27] audit: type=1800 audit(1575904600.373:27): pid=9031 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 '10.128.0.172' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 74.463058][ T9181] ================================================================== [ 74.463116][ T9181] BUG: KASAN: slab-out-of-bounds in fbcon_get_font+0x2b2/0x5e0 [ 74.463125][ T9181] Read of size 2 at addr ffff8880948f1910 by task syz-executor204/9181 [ 74.463129][ T9181] [ 74.463143][ T9181] CPU: 0 PID: 9181 Comm: syz-executor204 Not tainted 5.5.0-rc1-syzkaller #0 [ 74.463150][ T9181] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 74.463155][ T9181] Call Trace: [ 74.463174][ T9181] dump_stack+0x197/0x210 [ 74.463186][ T9181] ? fbcon_get_font+0x2b2/0x5e0 [ 74.463208][ T9181] print_address_description.constprop.0.cold+0xd4/0x30b [ 74.463222][ T9181] ? fbcon_get_font+0x2b2/0x5e0 [ 74.463242][ T9181] ? fbcon_get_font+0x2b2/0x5e0 [ 74.463255][ T9181] __kasan_report.cold+0x1b/0x41 [ 74.463271][ T9181] ? fbcon_get_font+0x2b2/0x5e0 [ 74.463287][ T9181] kasan_report+0x12/0x20 [ 74.463299][ T9181] check_memory_region+0x134/0x1a0 [ 74.463312][ T9181] memcpy+0x24/0x50 [ 74.463330][ T9181] fbcon_get_font+0x2b2/0x5e0 [ 74.463346][ T9181] ? display_to_var+0x7e0/0x7e0 [ 74.463362][ T9181] con_font_op+0x20b/0x1270 [ 74.463377][ T9181] ? lock_downgrade+0x920/0x920 [ 74.463394][ T9181] ? con_write+0xd0/0xd0 [ 74.463420][ T9181] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 74.463434][ T9181] ? _copy_from_user+0x12c/0x1a0 [ 74.463452][ T9181] vt_ioctl+0x1d29/0x26d0 [ 74.463504][ T9181] ? complete_change_console+0x3a0/0x3a0 [ 74.463517][ T9181] ? lock_downgrade+0x920/0x920 [ 74.463533][ T9181] ? rwlock_bug.part.0+0x90/0x90 [ 74.463550][ T9181] ? tomoyo_path_number_perm+0x214/0x520 [ 74.463560][ T9181] ? find_held_lock+0x35/0x130 [ 74.463576][ T9181] ? __sanitizer_cov_trace_switch+0x49/0x80 [ 74.463590][ T9181] ? tty_jobctrl_ioctl+0x50/0xd40 [ 74.463602][ T9181] ? complete_change_console+0x3a0/0x3a0 [ 74.463618][ T9181] tty_ioctl+0xa37/0x14f0 [ 74.463632][ T9181] ? tty_vhangup+0x30/0x30 [ 74.463644][ T9181] ? tomoyo_path_number_perm+0x454/0x520 [ 74.463659][ T9181] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 74.463670][ T9181] ? tomoyo_path_number_perm+0x25e/0x520 [ 74.463684][ T9181] ? tomoyo_execute_permission+0x4a0/0x4a0 [ 74.463710][ T9181] ? tty_vhangup+0x30/0x30 [ 74.463724][ T9181] do_vfs_ioctl+0x977/0x14e0 [ 74.463739][ T9181] ? compat_ioctl_preallocate+0x220/0x220 [ 74.463755][ T9181] ? kmem_cache_free+0x26b/0x320 [ 74.463771][ T9181] ? putname+0xf4/0x130 [ 74.463787][ T9181] ? do_sys_open+0x31d/0x5d0 [ 74.463802][ T9181] ? tomoyo_file_ioctl+0x23/0x30 [ 74.463815][ T9181] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 74.463828][ T9181] ? security_file_ioctl+0x8d/0xc0 [ 74.463848][ T9181] ksys_ioctl+0xab/0xd0 [ 74.463863][ T9181] __x64_sys_ioctl+0x73/0xb0 [ 74.463883][ T9181] do_syscall_64+0xfa/0x790 [ 74.463904][ T9181] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 74.463914][ T9181] RIP: 0033:0x440299 [ 74.463929][ T9181] Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 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 5b 14 fc ff c3 66 2e 0f 1f 84 00 00 00 00 [ 74.463936][ T9181] RSP: 002b:00007ffdcf3de038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 74.463949][ T9181] RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440299 [ 74.463956][ T9181] RDX: 0000000020000040 RSI: 0000000000004b6b RDI: 0000000000000005 [ 74.463964][ T9181] RBP: 00000000006ca018 R08: 000000000000000d R09: 00000000004002c8 [ 74.463971][ T9181] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000401b80 [ 74.463977][ T9181] R13: 0000000000401c10 R14: 0000000000000000 R15: 0000000000000000 [ 74.463996][ T9181] [ 74.464003][ T9181] Allocated by task 9181: [ 74.464016][ T9181] save_stack+0x23/0x90 [ 74.464027][ T9181] __kasan_kmalloc.constprop.0+0xcf/0xe0 [ 74.464037][ T9181] kasan_kmalloc+0x9/0x10 [ 74.464046][ T9181] __kmalloc+0x163/0x770 [ 74.464056][ T9181] fbcon_set_font+0x32d/0x860 [ 74.464068][ T9181] con_font_op+0xe30/0x1270 [ 74.464080][ T9181] vt_ioctl+0xd2e/0x26d0 [ 74.464092][ T9181] tty_ioctl+0xa37/0x14f0 [ 74.464102][ T9181] do_vfs_ioctl+0x977/0x14e0 [ 74.464113][ T9181] ksys_ioctl+0xab/0xd0 [ 74.464123][ T9181] __x64_sys_ioctl+0x73/0xb0 [ 74.464135][ T9181] do_syscall_64+0xfa/0x790 [ 74.464147][ T9181] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 74.464151][ T9181] [ 74.464157][ T9181] Freed by task 8925: [ 74.464168][ T9181] save_stack+0x23/0x90 [ 74.464179][ T9181] __kasan_slab_free+0x102/0x150 [ 74.464194][ T9181] kasan_slab_free+0xe/0x10 [ 74.464204][ T9181] kfree+0x10a/0x2c0 [ 74.464215][ T9181] tomoyo_supervisor+0x360/0xef0 [ 74.464227][ T9181] tomoyo_path_permission+0x263/0x360 [ 74.464239][ T9181] tomoyo_path_perm+0x318/0x430 [ 74.464251][ T9181] tomoyo_inode_getattr+0x1d/0x30 [ 74.464263][ T9181] security_inode_getattr+0xf2/0x150 [ 74.464278][ T9181] vfs_getattr+0x25/0x70 [ 74.464287][ T9181] vfs_statx_fd+0x71/0xc0 [ 74.464297][ T9181] __do_sys_newfstat+0x9b/0x120 [ 74.464308][ T9181] __x64_sys_newfstat+0x54/0x80 [ 74.464318][ T9181] do_syscall_64+0xfa/0x790 [ 74.464328][ T9181] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 74.464331][ T9181] [ 74.464339][ T9181] The buggy address belongs to the object at ffff8880948f1800 [ 74.464339][ T9181] which belongs to the cache kmalloc-512 of size 512 [ 74.464350][ T9181] The buggy address is located 272 bytes inside of [ 74.464350][ T9181] 512-byte region [ffff8880948f1800, ffff8880948f1a00) [ 74.464354][ T9181] The buggy address belongs to the page: [ 74.464366][ T9181] page:ffffea0002523c40 refcount:1 mapcount:0 mapping:ffff8880aa400a80 index:0x0 [ 74.464385][ T9181] raw: 00fffe0000000200 ffffea0002a478c8 ffffea0002a6a008 ffff8880aa400a80 [ 74.464400][ T9181] raw: 0000000000000000 ffff8880948f1000 0000000100000004 0000000000000000 [ 74.464406][ T9181] page dumped because: kasan: bad access detected [ 74.464409][ T9181] [ 74.464413][ T9181] Memory state around the buggy address: [ 74.464423][ T9181] ffff8880948f1800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 74.464434][ T9181] ffff8880948f1880: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 74.464444][ T9181] >ffff8880948f1900: 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 74.464448][ T9181] ^ [ 74.464464][ T9181] ffff8880948f1980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 74.464475][ T9181] ffff8880948f1a00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 74.464480][ T9181] ================================================================== [ 74.464484][ T9181] Disabling lock debugging due to kernel taint [ 74.464492][ T9181] Kernel panic - not syncing: panic_on_warn set ... [ 74.464505][ T9181] CPU: 0 PID: 9181 Comm: syz-executor204 Tainted: G B 5.5.0-rc1-syzkaller #0 [ 74.464511][ T9181] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 74.464513][ T9181] Call Trace: [ 74.464528][ T9181] dump_stack+0x197/0x210 [ 74.464544][ T9181] panic+0x2e3/0x75c [ 74.464556][ T9181] ? add_taint.cold+0x16/0x16 [ 74.464582][ T9181] ? trace_hardirqs_on+0x67/0x240 [ 74.464592][ T9181] ? trace_hardirqs_on+0x5e/0x240 [ 74.464606][ T9181] ? fbcon_get_font+0x2b2/0x5e0 [ 74.464616][ T9181] end_report+0x47/0x4f [ 74.464625][ T9181] ? fbcon_get_font+0x2b2/0x5e0 [ 74.464634][ T9181] __kasan_report.cold+0xe/0x41 [ 74.464647][ T9181] ? fbcon_get_font+0x2b2/0x5e0 [ 74.464657][ T9181] kasan_report+0x12/0x20 [ 74.464667][ T9181] check_memory_region+0x134/0x1a0 [ 74.464674][ T9181] memcpy+0x24/0x50 [ 74.464682][ T9181] fbcon_get_font+0x2b2/0x5e0 [ 74.464691][ T9181] ? display_to_var+0x7e0/0x7e0 [ 74.464699][ T9181] con_font_op+0x20b/0x1270 [ 74.464707][ T9181] ? lock_downgrade+0x920/0x920 [ 74.464715][ T9181] ? con_write+0xd0/0xd0 [ 74.464726][ T9181] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 74.464736][ T9181] ? _copy_from_user+0x12c/0x1a0 [ 74.464744][ T9181] vt_ioctl+0x1d29/0x26d0 [ 74.464754][ T9181] ? complete_change_console+0x3a0/0x3a0 [ 74.464760][ T9181] ? lock_downgrade+0x920/0x920 [ 74.464768][ T9181] ? rwlock_bug.part.0+0x90/0x90 [ 74.464775][ T9181] ? tomoyo_path_number_perm+0x214/0x520 [ 74.464782][ T9181] ? find_held_lock+0x35/0x130 [ 74.464790][ T9181] ? __sanitizer_cov_trace_switch+0x49/0x80 [ 74.464798][ T9181] ? tty_jobctrl_ioctl+0x50/0xd40 [ 74.464806][ T9181] ? complete_change_console+0x3a0/0x3a0 [ 74.464813][ T9181] tty_ioctl+0xa37/0x14f0 [ 74.464821][ T9181] ? tty_vhangup+0x30/0x30 [ 74.464827][ T9181] ? tomoyo_path_number_perm+0x454/0x520 [ 74.464836][ T9181] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 74.464843][ T9181] ? tomoyo_path_number_perm+0x25e/0x520 [ 74.464851][ T9181] ? tomoyo_execute_permission+0x4a0/0x4a0 [ 74.464862][ T9181] ? tty_vhangup+0x30/0x30 [ 74.464869][ T9181] do_vfs_ioctl+0x977/0x14e0 [ 74.464877][ T9181] ? compat_ioctl_preallocate+0x220/0x220 [ 74.464885][ T9181] ? kmem_cache_free+0x26b/0x320 [ 74.464893][ T9181] ? putname+0xf4/0x130 [ 74.464902][ T9181] ? do_sys_open+0x31d/0x5d0 [ 74.464910][ T9181] ? tomoyo_file_ioctl+0x23/0x30 [ 74.464918][ T9181] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 74.464924][ T9181] ? security_file_ioctl+0x8d/0xc0 [ 74.464931][ T9181] ksys_ioctl+0xab/0xd0 [ 74.464939][ T9181] __x64_sys_ioctl+0x73/0xb0 [ 74.464947][ T9181] do_syscall_64+0xfa/0x790 [ 74.464955][ T9181] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 74.464961][ T9181] RIP: 0033:0x440299 [ 74.464968][ T9181] Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 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 5b 14 fc ff c3 66 2e 0f 1f 84 00 00 00 00 [ 74.464972][ T9181] RSP: 002b:00007ffdcf3de038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 74.464984][ T9181] RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440299 [ 74.464988][ T9181] RDX: 0000000020000040 RSI: 0000000000004b6b RDI: 0000000000000005 [ 74.464992][ T9181] RBP: 00000000006ca018 R08: 000000000000000d R09: 00000000004002c8 [ 74.464996][ T9181] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000401b80 [ 74.465000][ T9181] R13: 0000000000401c10 R14: 0000000000000000 R15: 0000000000000000 [ 74.466616][ T9181] Kernel Offset: disabled [ 75.447226][ T9181] Rebooting in 86400 seconds..