[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 71.331769][ T28] audit: type=1800 audit(1576970604.752:25): pid=9244 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 71.357917][ T28] audit: type=1800 audit(1576970604.752:26): pid=9244 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 71.409277][ T28] audit: type=1800 audit(1576970604.752:27): pid=9244 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 '10.128.1.35' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 82.220624][ T9399] ================================================================== [ 82.220682][ T9399] BUG: KASAN: slab-out-of-bounds in fbcon_get_font+0x2b2/0x5e0 [ 82.220694][ T9399] Read of size 2 at addr ffff8880a44f8d10 by task syz-executor248/9399 [ 82.220698][ T9399] [ 82.220714][ T9399] CPU: 0 PID: 9399 Comm: syz-executor248 Not tainted 5.5.0-rc2-next-20191220-syzkaller #0 [ 82.220721][ T9399] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 82.220727][ T9399] Call Trace: [ 82.220744][ T9399] dump_stack+0x197/0x210 [ 82.220759][ T9399] ? fbcon_get_font+0x2b2/0x5e0 [ 82.220781][ T9399] print_address_description.constprop.0.cold+0xd4/0x30b [ 82.220795][ T9399] ? fbcon_get_font+0x2b2/0x5e0 [ 82.220808][ T9399] ? fbcon_get_font+0x2b2/0x5e0 [ 82.220823][ T9399] __kasan_report.cold+0x1b/0x41 [ 82.220840][ T9399] ? fbcon_get_font+0x2b2/0x5e0 [ 82.220858][ T9399] kasan_report+0x12/0x20 [ 82.220875][ T9399] check_memory_region+0x134/0x1a0 [ 82.220891][ T9399] memcpy+0x24/0x50 [ 82.220909][ T9399] fbcon_get_font+0x2b2/0x5e0 [ 82.220928][ T9399] ? display_to_var+0x7e0/0x7e0 [ 82.220945][ T9399] con_font_op+0x20b/0x1270 [ 82.220962][ T9399] ? lock_downgrade+0x920/0x920 [ 82.220978][ T9399] ? con_write+0xd0/0xd0 [ 82.221008][ T9399] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 82.221026][ T9399] ? _copy_from_user+0x12c/0x1a0 [ 82.221047][ T9399] vt_ioctl+0x1d29/0x26d0 [ 82.221066][ T9399] ? complete_change_console+0x3a0/0x3a0 [ 82.221089][ T9399] ? tomoyo_execute_permission+0x4a0/0x4a0 [ 82.221114][ T9399] ? __sanitizer_cov_trace_switch+0x49/0x80 [ 82.221133][ T9399] ? tty_jobctrl_ioctl+0x50/0xd40 [ 82.221149][ T9399] ? complete_change_console+0x3a0/0x3a0 [ 82.221165][ T9399] tty_ioctl+0xa37/0x14f0 [ 82.221182][ T9399] ? tty_vhangup+0x30/0x30 [ 82.221197][ T9399] ? __sanitizer_cov_trace_const_cmp2+0x18/0x20 [ 82.221211][ T9399] ? do_vfs_ioctl+0x11b/0x1340 [ 82.221229][ T9399] ? ioctl_file_clone+0x180/0x180 [ 82.221242][ T9399] ? file_open_root+0x5f0/0x5f0 [ 82.221257][ T9399] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 82.221276][ T9399] ? rcu_lockdep_current_cpu_online+0xe3/0x130 [ 82.221303][ T9399] ? tomoyo_file_ioctl+0x23/0x30 [ 82.221320][ T9399] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 82.221336][ T9399] ? security_file_ioctl+0x8d/0xc0 [ 82.221348][ T9399] ? tty_vhangup+0x30/0x30 [ 82.221365][ T9399] ksys_ioctl+0x123/0x180 [ 82.221383][ T9399] __x64_sys_ioctl+0x73/0xb0 [ 82.221402][ T9399] do_syscall_64+0xfa/0x790 [ 82.221420][ T9399] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 82.221429][ T9399] RIP: 0033:0x440299 [ 82.221444][ T9399] 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 [ 82.221452][ T9399] RSP: 002b:00007ffc79647818 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 82.221466][ T9399] RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440299 [ 82.221475][ T9399] RDX: 0000000020000040 RSI: 0000000000004b6b RDI: 0000000000000005 [ 82.221492][ T9399] RBP: 00000000006ca018 R08: 000000000000000d R09: 00000000004002c8 [ 82.221500][ T9399] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000401b80 [ 82.221508][ T9399] R13: 0000000000401c10 R14: 0000000000000000 R15: 0000000000000000 [ 82.221526][ T9399] [ 82.221533][ T9399] Allocated by task 9399: [ 82.221547][ T9399] save_stack+0x23/0x90 [ 82.221561][ T9399] __kasan_kmalloc.constprop.0+0xcf/0xe0 [ 82.221573][ T9399] kasan_kmalloc+0x9/0x10 [ 82.221585][ T9399] __kmalloc+0x163/0x770 [ 82.221599][ T9399] fbcon_set_font+0x32d/0x860 [ 82.221611][ T9399] con_font_op+0xe30/0x1270 [ 82.221622][ T9399] vt_ioctl+0xd2e/0x26d0 [ 82.221633][ T9399] tty_ioctl+0xa37/0x14f0 [ 82.221645][ T9399] ksys_ioctl+0x123/0x180 [ 82.221657][ T9399] __x64_sys_ioctl+0x73/0xb0 [ 82.221671][ T9399] do_syscall_64+0xfa/0x790 [ 82.221683][ T9399] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 82.221687][ T9399] [ 82.221694][ T9399] Freed by task 9137: [ 82.221706][ T9399] save_stack+0x23/0x90 [ 82.221717][ T9399] __kasan_slab_free+0x102/0x150 [ 82.221728][ T9399] kasan_slab_free+0xe/0x10 [ 82.221739][ T9399] kfree+0x10a/0x2c0 [ 82.221753][ T9399] skb_free_head+0x93/0xb0 [ 82.221766][ T9399] skb_release_data+0x613/0x8c0 [ 82.221778][ T9399] skb_release_all+0x4d/0x60 [ 82.221789][ T9399] consume_skb+0xfb/0x410 [ 82.221802][ T9399] netlink_unicast+0x594/0x7d0 [ 82.221814][ T9399] netlink_sendmsg+0x91c/0xea0 [ 82.221826][ T9399] sock_sendmsg+0xd7/0x130 [ 82.221838][ T9399] ____sys_sendmsg+0x753/0x880 [ 82.221851][ T9399] ___sys_sendmsg+0x100/0x170 [ 82.221863][ T9399] __sys_sendmsg+0x105/0x1d0 [ 82.221876][ T9399] __x64_sys_sendmsg+0x78/0xb0 [ 82.221891][ T9399] do_syscall_64+0xfa/0x790 [ 82.221905][ T9399] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 82.221909][ T9399] [ 82.221920][ T9399] The buggy address belongs to the object at ffff8880a44f8c00 [ 82.221920][ T9399] which belongs to the cache kmalloc-512 of size 512 [ 82.221933][ T9399] The buggy address is located 272 bytes inside of [ 82.221933][ T9399] 512-byte region [ffff8880a44f8c00, ffff8880a44f8e00) [ 82.221938][ T9399] The buggy address belongs to the page: [ 82.221953][ T9399] page:ffffea0002913e00 refcount:1 mapcount:0 mapping:ffff8880aa400a80 index:0xffff8880a44f8800 [ 82.221973][ T9399] raw: 00fffe0000000200 ffffea0002827c08 ffffea00029f0588 ffff8880aa400a80 [ 82.221990][ T9399] raw: ffff8880a44f8800 ffff8880a44f8000 0000000100000003 0000000000000000 [ 82.221997][ T9399] page dumped because: kasan: bad access detected [ 82.222001][ T9399] [ 82.222006][ T9399] Memory state around the buggy address: [ 82.222018][ T9399] ffff8880a44f8c00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 82.222030][ T9399] ffff8880a44f8c80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 82.222042][ T9399] >ffff8880a44f8d00: 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 82.222047][ T9399] ^ [ 82.222059][ T9399] ffff8880a44f8d80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 82.222071][ T9399] ffff8880a44f8e00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 82.222076][ T9399] ================================================================== [ 82.222081][ T9399] Disabling lock debugging due to kernel taint [ 82.222089][ T9399] Kernel panic - not syncing: panic_on_warn set ... [ 82.222105][ T9399] CPU: 0 PID: 9399 Comm: syz-executor248 Tainted: G B 5.5.0-rc2-next-20191220-syzkaller #0 [ 82.222113][ T9399] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 82.222117][ T9399] Call Trace: [ 82.222130][ T9399] dump_stack+0x197/0x210 [ 82.222148][ T9399] panic+0x2e3/0x75c [ 82.222162][ T9399] ? add_taint.cold+0x16/0x16 [ 82.222183][ T9399] ? trace_hardirqs_on+0x67/0x240 [ 82.222198][ T9399] ? trace_hardirqs_on+0x5e/0x240 [ 82.222212][ T9399] ? fbcon_get_font+0x2b2/0x5e0 [ 82.222225][ T9399] end_report+0x47/0x4f [ 82.222237][ T9399] ? fbcon_get_font+0x2b2/0x5e0 [ 82.222250][ T9399] __kasan_report.cold+0xe/0x41 [ 82.222264][ T9399] ? fbcon_get_font+0x2b2/0x5e0 [ 82.222279][ T9399] kasan_report+0x12/0x20 [ 82.222294][ T9399] check_memory_region+0x134/0x1a0 [ 82.222307][ T9399] memcpy+0x24/0x50 [ 82.222322][ T9399] fbcon_get_font+0x2b2/0x5e0 [ 82.222337][ T9399] ? display_to_var+0x7e0/0x7e0 [ 82.222350][ T9399] con_font_op+0x20b/0x1270 [ 82.222364][ T9399] ? lock_downgrade+0x920/0x920 [ 82.222377][ T9399] ? con_write+0xd0/0xd0 [ 82.222399][ T9399] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 82.222416][ T9399] ? _copy_from_user+0x12c/0x1a0 [ 82.222432][ T9399] vt_ioctl+0x1d29/0x26d0 [ 82.222447][ T9399] ? complete_change_console+0x3a0/0x3a0 [ 82.222466][ T9399] ? tomoyo_execute_permission+0x4a0/0x4a0 [ 82.222492][ T9399] ? __sanitizer_cov_trace_switch+0x49/0x80 [ 82.222509][ T9399] ? tty_jobctrl_ioctl+0x50/0xd40 [ 82.222524][ T9399] ? complete_change_console+0x3a0/0x3a0 [ 82.222537][ T9399] tty_ioctl+0xa37/0x14f0 [ 82.222550][ T9399] ? tty_vhangup+0x30/0x30 [ 82.222566][ T9399] ? __sanitizer_cov_trace_const_cmp2+0x18/0x20 [ 82.222579][ T9399] ? do_vfs_ioctl+0x11b/0x1340 [ 82.222596][ T9399] ? ioctl_file_clone+0x180/0x180 [ 82.222609][ T9399] ? file_open_root+0x5f0/0x5f0 [ 82.222624][ T9399] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 82.222642][ T9399] ? rcu_lockdep_current_cpu_online+0xe3/0x130 [ 82.222661][ T9399] ? tomoyo_file_ioctl+0x23/0x30 [ 82.222677][ T9399] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 82.222692][ T9399] ? security_file_ioctl+0x8d/0xc0 [ 82.222703][ T9399] ? tty_vhangup+0x30/0x30 [ 82.222718][ T9399] ksys_ioctl+0x123/0x180 [ 82.222733][ T9399] __x64_sys_ioctl+0x73/0xb0 [ 82.222750][ T9399] do_syscall_64+0xfa/0x790 [ 82.222765][ T9399] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 82.222774][ T9399] RIP: 0033:0x440299 [ 82.222788][ T9399] 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 [ 82.222795][ T9399] RSP: 002b:00007ffc79647818 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 82.222807][ T9399] RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440299 [ 82.222814][ T9399] RDX: 0000000020000040 RSI: 0000000000004b6b RDI: 0000000000000005 [ 82.222821][ T9399] RBP: 00000000006ca018 R08: 000000000000000d R09: 00000000004002c8 [ 82.222829][ T9399] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000401b80 [ 82.222836][ T9399] R13: 0000000000401c10 R14: 0000000000000000 R15: 0000000000000000 [ 82.223715][ T9399] Kernel Offset: disabled [ 83.155596][ T9399] Rebooting in 86400 seconds..