[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 60.353540][ T26] audit: type=1800 audit(1575407549.211:25): pid=8858 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 60.373536][ T26] audit: type=1800 audit(1575407549.211:26): pid=8858 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 60.400304][ T26] audit: type=1800 audit(1575407549.221:27): pid=8858 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 '10.128.1.54' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 88.399625][ T9010] ================================================================== [ 88.399666][ T9010] BUG: KASAN: slab-out-of-bounds in fbcon_get_font+0x2b2/0x5e0 [ 88.399674][ T9010] Read of size 16 at addr ffff88809411aa10 by task syz-executor630/9010 [ 88.399677][ T9010] [ 88.399687][ T9010] CPU: 1 PID: 9010 Comm: syz-executor630 Not tainted 5.4.0-syzkaller #0 [ 88.399691][ T9010] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 88.399695][ T9010] Call Trace: [ 88.399708][ T9010] dump_stack+0x197/0x210 [ 88.399716][ T9010] ? fbcon_get_font+0x2b2/0x5e0 [ 88.399728][ T9010] print_address_description.constprop.0.cold+0xd4/0x30b [ 88.399735][ T9010] ? fbcon_get_font+0x2b2/0x5e0 [ 88.399743][ T9010] ? fbcon_get_font+0x2b2/0x5e0 [ 88.399750][ T9010] __kasan_report.cold+0x1b/0x41 [ 88.399761][ T9010] ? fbcon_get_font+0x2b2/0x5e0 [ 88.399770][ T9010] kasan_report+0x12/0x20 [ 88.399779][ T9010] check_memory_region+0x134/0x1a0 [ 88.399786][ T9010] memcpy+0x24/0x50 [ 88.399795][ T9010] fbcon_get_font+0x2b2/0x5e0 [ 88.399805][ T9010] ? display_to_var+0x7e0/0x7e0 [ 88.399816][ T9010] con_font_op+0x20b/0x1250 [ 88.399826][ T9010] ? lock_downgrade+0x920/0x920 [ 88.399834][ T9010] ? con_write+0xd0/0xd0 [ 88.399851][ T9010] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 88.399860][ T9010] ? _copy_from_user+0x12c/0x1a0 [ 88.399870][ T9010] vt_ioctl+0x181a/0x26d0 [ 88.399879][ T9010] ? complete_change_console+0x3a0/0x3a0 [ 88.399886][ T9010] ? lock_downgrade+0x920/0x920 [ 88.399896][ T9010] ? rwlock_bug.part.0+0x90/0x90 [ 88.399905][ T9010] ? tomoyo_path_number_perm+0x214/0x520 [ 88.399914][ T9010] ? find_held_lock+0x35/0x130 [ 88.399924][ T9010] ? __sanitizer_cov_trace_switch+0x49/0x80 [ 88.399935][ T9010] ? tty_jobctrl_ioctl+0x50/0xd40 [ 88.399942][ T9010] ? complete_change_console+0x3a0/0x3a0 [ 88.399951][ T9010] tty_ioctl+0xa37/0x14f0 [ 88.399960][ T9010] ? tty_vhangup+0x30/0x30 [ 88.399967][ T9010] ? tomoyo_path_number_perm+0x454/0x520 [ 88.399977][ T9010] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 88.399984][ T9010] ? tomoyo_path_number_perm+0x25e/0x520 [ 88.399993][ T9010] ? tomoyo_execute_permission+0x4a0/0x4a0 [ 88.400010][ T9010] ? tty_vhangup+0x30/0x30 [ 88.400020][ T9010] do_vfs_ioctl+0x977/0x14e0 [ 88.400030][ T9010] ? compat_ioctl_preallocate+0x220/0x220 [ 88.400040][ T9010] ? kmem_cache_free+0x26b/0x320 [ 88.400051][ T9010] ? putname+0xf4/0x130 [ 88.400061][ T9010] ? do_sys_open+0x31d/0x5d0 [ 88.400072][ T9010] ? tomoyo_file_ioctl+0x23/0x30 [ 88.400080][ T9010] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 88.400090][ T9010] ? security_file_ioctl+0x8d/0xc0 [ 88.400099][ T9010] ksys_ioctl+0xab/0xd0 [ 88.400109][ T9010] __x64_sys_ioctl+0x73/0xb0 [ 88.400119][ T9010] do_syscall_64+0xfa/0x790 [ 88.400132][ T9010] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 88.400138][ T9010] RIP: 0033:0x4444d9 [ 88.400147][ T9010] 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 7b d8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 [ 88.400151][ T9010] RSP: 002b:00007ffddaa21218 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 88.400169][ T9010] RAX: ffffffffffffffda RBX: 00007ffddaa21220 RCX: 00000000004444d9 [ 88.400176][ T9010] RDX: 0000000020000440 RSI: 0000000000004b72 RDI: 0000000000000005 [ 88.400182][ T9010] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000400da0 [ 88.400188][ T9010] R10: 00007ffddaa20d60 R11: 0000000000000246 R12: 00000000004021e0 [ 88.400195][ T9010] R13: 0000000000402270 R14: 0000000000000000 R15: 0000000000000000 [ 88.400211][ T9010] [ 88.400216][ T9010] Allocated by task 9010: [ 88.400226][ T9010] save_stack+0x23/0x90 [ 88.400236][ T9010] __kasan_kmalloc.constprop.0+0xcf/0xe0 [ 88.400246][ T9010] kasan_kmalloc+0x9/0x10 [ 88.400260][ T9010] __kmalloc+0x163/0x770 [ 88.400272][ T9010] fbcon_set_font+0x32d/0x860 [ 88.400282][ T9010] con_font_op+0xe18/0x1250 [ 88.400293][ T9010] vt_ioctl+0xd2e/0x26d0 [ 88.400303][ T9010] tty_ioctl+0xa37/0x14f0 [ 88.400313][ T9010] do_vfs_ioctl+0x977/0x14e0 [ 88.400323][ T9010] ksys_ioctl+0xab/0xd0 [ 88.400334][ T9010] __x64_sys_ioctl+0x73/0xb0 [ 88.400344][ T9010] do_syscall_64+0xfa/0x790 [ 88.400354][ T9010] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 88.400356][ T9010] [ 88.400360][ T9010] Freed by task 0: [ 88.400362][ T9010] (stack is not available) [ 88.400364][ T9010] [ 88.400370][ T9010] The buggy address belongs to the object at ffff88809411a000 [ 88.400370][ T9010] which belongs to the cache kmalloc-4k of size 4096 [ 88.400377][ T9010] The buggy address is located 2576 bytes inside of [ 88.400377][ T9010] 4096-byte region [ffff88809411a000, ffff88809411b000) [ 88.400380][ T9010] The buggy address belongs to the page: [ 88.400389][ T9010] page:ffffea0002504680 refcount:1 mapcount:0 mapping:ffff8880aa402000 index:0x0 compound_mapcount: 0 [ 88.400400][ T9010] raw: 00fffe0000010200 ffffea0002588c08 ffffea0002572188 ffff8880aa402000 [ 88.400409][ T9010] raw: 0000000000000000 ffff88809411a000 0000000100000001 0000000000000000 [ 88.400412][ T9010] page dumped because: kasan: bad access detected [ 88.400415][ T9010] [ 88.400417][ T9010] Memory state around the buggy address: [ 88.400423][ T9010] ffff88809411a900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 88.400429][ T9010] ffff88809411a980: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 88.400435][ T9010] >ffff88809411aa00: 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 88.400438][ T9010] ^ [ 88.400448][ T9010] ffff88809411aa80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 88.400454][ T9010] ffff88809411ab00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 88.400457][ T9010] ================================================================== [ 88.400460][ T9010] Disabling lock debugging due to kernel taint [ 88.400570][ T9010] Kernel panic - not syncing: panic_on_warn set ... [ 88.400584][ T9010] CPU: 1 PID: 9010 Comm: syz-executor630 Tainted: G B 5.4.0-syzkaller #0 [ 88.400594][ T9010] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 88.400602][ T9010] Call Trace: [ 88.400617][ T9010] dump_stack+0x197/0x210 [ 88.400632][ T9010] panic+0x2e3/0x75c [ 88.400645][ T9010] ? add_taint.cold+0x16/0x16 [ 88.400662][ T9010] ? trace_hardirqs_on+0x5e/0x240 [ 88.400676][ T9010] ? trace_hardirqs_on+0x5e/0x240 [ 88.400690][ T9010] ? fbcon_get_font+0x2b2/0x5e0 [ 88.400703][ T9010] end_report+0x47/0x4f [ 88.400717][ T9010] ? fbcon_get_font+0x2b2/0x5e0 [ 88.400730][ T9010] __kasan_report.cold+0xe/0x41 [ 88.400744][ T9010] ? fbcon_get_font+0x2b2/0x5e0 [ 88.400757][ T9010] kasan_report+0x12/0x20 [ 88.400771][ T9010] check_memory_region+0x134/0x1a0 [ 88.400784][ T9010] memcpy+0x24/0x50 [ 88.400797][ T9010] fbcon_get_font+0x2b2/0x5e0 [ 88.400812][ T9010] ? display_to_var+0x7e0/0x7e0 [ 88.400824][ T9010] con_font_op+0x20b/0x1250 [ 88.400838][ T9010] ? lock_downgrade+0x920/0x920 [ 88.400851][ T9010] ? con_write+0xd0/0xd0 [ 88.400867][ T9010] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 88.400880][ T9010] ? _copy_from_user+0x12c/0x1a0 [ 88.400894][ T9010] vt_ioctl+0x181a/0x26d0 [ 88.400908][ T9010] ? complete_change_console+0x3a0/0x3a0 [ 88.400920][ T9010] ? lock_downgrade+0x920/0x920 [ 88.400934][ T9010] ? rwlock_bug.part.0+0x90/0x90 [ 88.400949][ T9010] ? tomoyo_path_number_perm+0x214/0x520 [ 88.400963][ T9010] ? find_held_lock+0x35/0x130 [ 88.400978][ T9010] ? __sanitizer_cov_trace_switch+0x49/0x80 [ 88.400993][ T9010] ? tty_jobctrl_ioctl+0x50/0xd40 [ 88.401006][ T9010] ? complete_change_console+0x3a0/0x3a0 [ 88.401019][ T9010] tty_ioctl+0xa37/0x14f0 [ 88.401032][ T9010] ? tty_vhangup+0x30/0x30 [ 88.401045][ T9010] ? tomoyo_path_number_perm+0x454/0x520 [ 88.401060][ T9010] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 88.401073][ T9010] ? tomoyo_path_number_perm+0x25e/0x520 [ 88.401086][ T9010] ? tomoyo_execute_permission+0x4a0/0x4a0 [ 88.401108][ T9010] ? tty_vhangup+0x30/0x30 [ 88.401121][ T9010] do_vfs_ioctl+0x977/0x14e0 [ 88.401136][ T9010] ? compat_ioctl_preallocate+0x220/0x220 [ 88.401149][ T9010] ? kmem_cache_free+0x26b/0x320 [ 88.401163][ T9010] ? putname+0xf4/0x130 [ 88.401176][ T9010] ? do_sys_open+0x31d/0x5d0 [ 88.401190][ T9010] ? tomoyo_file_ioctl+0x23/0x30 [ 88.401209][ T9010] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 88.401224][ T9010] ? security_file_ioctl+0x8d/0xc0 [ 88.401237][ T9010] ksys_ioctl+0xab/0xd0 [ 88.401251][ T9010] __x64_sys_ioctl+0x73/0xb0 [ 88.401265][ T9010] do_syscall_64+0xfa/0x790 [ 88.401281][ T9010] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 88.401292][ T9010] RIP: 0033:0x4444d9 [ 88.401306][ T9010] 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 7b d8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 [ 88.401316][ T9010] RSP: 002b:00007ffddaa21218 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 88.401335][ T9010] RAX: ffffffffffffffda RBX: 00007ffddaa21220 RCX: 00000000004444d9 [ 88.401346][ T9010] RDX: 0000000020000440 RSI: 0000000000004b72 RDI: 0000000000000005 [ 88.401351][ T9010] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000400da0 [ 88.401357][ T9010] R10: 00007ffddaa20d60 R11: 0000000000000246 R12: 00000000004021e0 [ 88.401362][ T9010] R13: 0000000000402270 R14: 0000000000000000 R15: 0000000000000000 [ 88.402989][ T9010] Kernel Offset: disabled [ 89.308080][ T9010] Rebooting in 86400 seconds..