[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 59.310675][ T26] audit: type=1800 audit(1575630165.619:25): pid=8836 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 59.330690][ T26] audit: type=1800 audit(1575630165.619:26): pid=8836 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 59.351118][ T26] audit: type=1800 audit(1575630165.619:27): pid=8836 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 '10.128.15.214' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 71.143193][ T8989] ================================================================== [ 71.143235][ T8989] BUG: KASAN: use-after-free in soft_cursor+0x439/0xa30 [ 71.143242][ T8989] Read of size 9 at addr ffff8880a1b23851 by task syz-executor549/8989 [ 71.143245][ T8989] [ 71.143254][ T8989] CPU: 0 PID: 8989 Comm: syz-executor549 Not tainted 5.4.0-syzkaller #0 [ 71.143259][ T8989] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 71.143263][ T8989] Call Trace: [ 71.143274][ T8989] dump_stack+0x197/0x210 [ 71.143283][ T8989] ? soft_cursor+0x439/0xa30 [ 71.143295][ T8989] print_address_description.constprop.0.cold+0xd4/0x30b [ 71.143303][ T8989] ? soft_cursor+0x439/0xa30 [ 71.143312][ T8989] ? soft_cursor+0x439/0xa30 [ 71.143319][ T8989] __kasan_report.cold+0x1b/0x41 [ 71.143329][ T8989] ? soft_cursor+0x439/0xa30 [ 71.143338][ T8989] kasan_report+0x12/0x20 [ 71.143347][ T8989] check_memory_region+0x134/0x1a0 [ 71.143354][ T8989] memcpy+0x24/0x50 [ 71.143364][ T8989] soft_cursor+0x439/0xa30 [ 71.143373][ T8989] ? lockdep_hardirqs_on+0x421/0x5e0 [ 71.143387][ T8989] bit_cursor+0x12fc/0x1a60 [ 71.143400][ T8989] ? bit_clear+0x530/0x530 [ 71.143410][ T8989] ? find_held_lock+0x35/0x130 [ 71.143425][ T8989] ? __sanitizer_cov_trace_switch+0x49/0x80 [ 71.143434][ T8989] ? get_color+0x225/0x430 [ 71.143445][ T8989] fbcon_cursor+0x487/0x660 [ 71.143453][ T8989] ? bit_clear+0x530/0x530 [ 71.143464][ T8989] hide_cursor+0x9d/0x2b0 [ 71.143473][ T8989] redraw_screen+0x60b/0x7d0 [ 71.143483][ T8989] ? respond_string+0x2c0/0x2c0 [ 71.143496][ T8989] vc_do_resize+0x10c9/0x1460 [ 71.143503][ T8989] ? down+0x50/0x90 [ 71.143520][ T8989] ? vc_uniscr_alloc+0xd0/0xd0 [ 71.143528][ T8989] ? lock_acquire+0x190/0x410 [ 71.143538][ T8989] ? vt_ioctl+0x1f56/0x26d0 [ 71.143549][ T8989] vc_resize+0x4d/0x60 [ 71.143558][ T8989] vt_ioctl+0x2076/0x26d0 [ 71.143568][ T8989] ? complete_change_console+0x3a0/0x3a0 [ 71.143575][ T8989] ? lock_downgrade+0x920/0x920 [ 71.143583][ T8989] ? rwlock_bug.part.0+0x90/0x90 [ 71.143593][ T8989] ? tomoyo_path_number_perm+0x214/0x520 [ 71.143602][ T8989] ? find_held_lock+0x35/0x130 [ 71.143610][ T8989] ? tomoyo_path_number_perm+0x214/0x520 [ 71.143618][ T8989] ? __sanitizer_cov_trace_switch+0x49/0x80 [ 71.143630][ T8989] ? tty_jobctrl_ioctl+0x50/0xd40 [ 71.143638][ T8989] ? complete_change_console+0x3a0/0x3a0 [ 71.143646][ T8989] tty_ioctl+0xa37/0x14f0 [ 71.143655][ T8989] ? tty_vhangup+0x30/0x30 [ 71.143662][ T8989] ? tomoyo_path_number_perm+0x454/0x520 [ 71.143672][ T8989] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 71.143680][ T8989] ? tomoyo_path_number_perm+0x25e/0x520 [ 71.143689][ T8989] ? tomoyo_execute_permission+0x4a0/0x4a0 [ 71.143710][ T8989] ? tty_vhangup+0x30/0x30 [ 71.143720][ T8989] do_vfs_ioctl+0x977/0x14e0 [ 71.143730][ T8989] ? compat_ioctl_preallocate+0x220/0x220 [ 71.143739][ T8989] ? kmem_cache_free+0x26b/0x320 [ 71.143749][ T8989] ? putname+0xf4/0x130 [ 71.143758][ T8989] ? do_sys_open+0x31d/0x5d0 [ 71.143768][ T8989] ? tomoyo_file_ioctl+0x23/0x30 [ 71.143777][ T8989] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 71.143787][ T8989] ? security_file_ioctl+0x8d/0xc0 [ 71.143796][ T8989] ksys_ioctl+0xab/0xd0 [ 71.143805][ T8989] __x64_sys_ioctl+0x73/0xb0 [ 71.143816][ T8989] do_syscall_64+0xfa/0x790 [ 71.143829][ T8989] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 71.143836][ T8989] RIP: 0033:0x440219 [ 71.143845][ T8989] 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 [ 71.143850][ T8989] RSP: 002b:00007ffe3702aa48 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 71.143858][ T8989] RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440219 [ 71.143862][ T8989] RDX: 00000000200002c0 RSI: 000000000000560a RDI: 0000000000000004 [ 71.143867][ T8989] RBP: 00000000006ca018 R08: 0000000000000001 R09: 00000000004002c8 [ 71.143872][ T8989] R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000401b00 [ 71.143876][ T8989] R13: 0000000000401b90 R14: 0000000000000000 R15: 0000000000000000 [ 71.143887][ T8989] [ 71.143891][ T8989] Allocated by task 8975: [ 71.143898][ T8989] save_stack+0x23/0x90 [ 71.143905][ T8989] __kasan_kmalloc.constprop.0+0xcf/0xe0 [ 71.143911][ T8989] kasan_kmalloc+0x9/0x10 [ 71.143919][ T8989] __kmalloc+0x163/0x770 [ 71.143928][ T8989] tomoyo_init_log+0x141f/0x2070 [ 71.143935][ T8989] tomoyo_supervisor+0x33f/0xef0 [ 71.143941][ T8989] tomoyo_path_permission+0x263/0x360 [ 71.143948][ T8989] tomoyo_check_open_permission+0x3a6/0x3e0 [ 71.143954][ T8989] tomoyo_file_open+0xa9/0xd0 [ 71.143962][ T8989] security_file_open+0x71/0x300 [ 71.143970][ T8989] do_dentry_open+0x37a/0x1380 [ 71.143975][ T8989] vfs_open+0xa0/0xd0 [ 71.143982][ T8989] path_openat+0x10e4/0x4710 [ 71.143989][ T8989] do_filp_open+0x1a1/0x280 [ 71.143995][ T8989] do_sys_open+0x3fe/0x5d0 [ 71.144001][ T8989] __x64_sys_open+0x7e/0xc0 [ 71.144008][ T8989] do_syscall_64+0xfa/0x790 [ 71.144016][ T8989] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 71.144018][ T8989] [ 71.144022][ T8989] Freed by task 8975: [ 71.144028][ T8989] save_stack+0x23/0x90 [ 71.144034][ T8989] __kasan_slab_free+0x102/0x150 [ 71.144040][ T8989] kasan_slab_free+0xe/0x10 [ 71.144045][ T8989] kfree+0x10a/0x2c0 [ 71.144053][ T8989] tomoyo_supervisor+0x360/0xef0 [ 71.144059][ T8989] tomoyo_path_permission+0x263/0x360 [ 71.144065][ T8989] tomoyo_check_open_permission+0x3a6/0x3e0 [ 71.144072][ T8989] tomoyo_file_open+0xa9/0xd0 [ 71.144079][ T8989] security_file_open+0x71/0x300 [ 71.144086][ T8989] do_dentry_open+0x37a/0x1380 [ 71.144092][ T8989] vfs_open+0xa0/0xd0 [ 71.144099][ T8989] path_openat+0x10e4/0x4710 [ 71.144106][ T8989] do_filp_open+0x1a1/0x280 [ 71.144112][ T8989] do_sys_open+0x3fe/0x5d0 [ 71.144118][ T8989] __x64_sys_open+0x7e/0xc0 [ 71.144125][ T8989] do_syscall_64+0xfa/0x790 [ 71.144133][ T8989] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 71.144135][ T8989] [ 71.144141][ T8989] The buggy address belongs to the object at ffff8880a1b23800 [ 71.144141][ T8989] which belongs to the cache kmalloc-512 of size 512 [ 71.144148][ T8989] The buggy address is located 81 bytes inside of [ 71.144148][ T8989] 512-byte region [ffff8880a1b23800, ffff8880a1b23a00) [ 71.144151][ T8989] The buggy address belongs to the page: [ 71.144160][ T8989] page:ffffea000286c8c0 refcount:1 mapcount:0 mapping:ffff8880aa400a80 index:0xffff8880a1b23000 [ 71.144171][ T8989] raw: 00fffe0000000200 ffffea00028bd888 ffffea0002a4a388 ffff8880aa400a80 [ 71.144179][ T8989] raw: ffff8880a1b23000 ffff8880a1b23000 0000000100000003 0000000000000000 [ 71.144183][ T8989] page dumped because: kasan: bad access detected [ 71.144186][ T8989] [ 71.144188][ T8989] Memory state around the buggy address: [ 71.144194][ T8989] ffff8880a1b23700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 71.144200][ T8989] ffff8880a1b23780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 71.144206][ T8989] >ffff8880a1b23800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 71.144209][ T8989] ^ [ 71.144215][ T8989] ffff8880a1b23880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 71.144221][ T8989] ffff8880a1b23900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 71.144224][ T8989] ================================================================== [ 71.144226][ T8989] Disabling lock debugging due to kernel taint [ 71.144231][ T8989] Kernel panic - not syncing: panic_on_warn set ... [ 71.144238][ T8989] CPU: 0 PID: 8989 Comm: syz-executor549 Tainted: G B 5.4.0-syzkaller #0 [ 71.144242][ T8989] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 71.144244][ T8989] Call Trace: [ 71.144251][ T8989] dump_stack+0x197/0x210 [ 71.144259][ T8989] panic+0x2e3/0x75c [ 71.144266][ T8989] ? add_taint.cold+0x16/0x16 [ 71.144277][ T8989] ? trace_hardirqs_on+0x67/0x240 [ 71.144284][ T8989] ? trace_hardirqs_on+0x5e/0x240 [ 71.144292][ T8989] ? soft_cursor+0x439/0xa30 [ 71.144299][ T8989] end_report+0x47/0x4f [ 71.144306][ T8989] ? soft_cursor+0x439/0xa30 [ 71.144312][ T8989] __kasan_report.cold+0xe/0x41 [ 71.144321][ T8989] ? soft_cursor+0x439/0xa30 [ 71.144328][ T8989] kasan_report+0x12/0x20 [ 71.144335][ T8989] check_memory_region+0x134/0x1a0 [ 71.144341][ T8989] memcpy+0x24/0x50 [ 71.144349][ T8989] soft_cursor+0x439/0xa30 [ 71.144356][ T8989] ? lockdep_hardirqs_on+0x421/0x5e0 [ 71.144366][ T8989] bit_cursor+0x12fc/0x1a60 [ 71.144376][ T8989] ? bit_clear+0x530/0x530 [ 71.144384][ T8989] ? find_held_lock+0x35/0x130 [ 71.144394][ T8989] ? __sanitizer_cov_trace_switch+0x49/0x80 [ 71.144401][ T8989] ? get_color+0x225/0x430 [ 71.144409][ T8989] fbcon_cursor+0x487/0x660 [ 71.144416][ T8989] ? bit_clear+0x530/0x530 [ 71.144424][ T8989] hide_cursor+0x9d/0x2b0 [ 71.144431][ T8989] redraw_screen+0x60b/0x7d0 [ 71.144439][ T8989] ? respond_string+0x2c0/0x2c0 [ 71.144448][ T8989] vc_do_resize+0x10c9/0x1460 [ 71.144455][ T8989] ? down+0x50/0x90 [ 71.144466][ T8989] ? vc_uniscr_alloc+0xd0/0xd0 [ 71.144472][ T8989] ? lock_acquire+0x190/0x410 [ 71.144479][ T8989] ? vt_ioctl+0x1f56/0x26d0 [ 71.144487][ T8989] vc_resize+0x4d/0x60 [ 71.144495][ T8989] vt_ioctl+0x2076/0x26d0 [ 71.144503][ T8989] ? complete_change_console+0x3a0/0x3a0 [ 71.144509][ T8989] ? lock_downgrade+0x920/0x920 [ 71.144517][ T8989] ? rwlock_bug.part.0+0x90/0x90 [ 71.144523][ T8989] ? tomoyo_path_number_perm+0x214/0x520 [ 71.144533][ T8989] ? find_held_lock+0x35/0x130 [ 71.144540][ T8989] ? tomoyo_path_number_perm+0x214/0x520 [ 71.144548][ T8989] ? __sanitizer_cov_trace_switch+0x49/0x80 [ 71.144556][ T8989] ? tty_jobctrl_ioctl+0x50/0xd40 [ 71.144564][ T8989] ? complete_change_console+0x3a0/0x3a0 [ 71.144570][ T8989] tty_ioctl+0xa37/0x14f0 [ 71.144577][ T8989] ? tty_vhangup+0x30/0x30 [ 71.144584][ T8989] ? tomoyo_path_number_perm+0x454/0x520 [ 71.144592][ T8989] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 71.144599][ T8989] ? tomoyo_path_number_perm+0x25e/0x520 [ 71.144606][ T8989] ? tomoyo_execute_permission+0x4a0/0x4a0 [ 71.144617][ T8989] ? tty_vhangup+0x30/0x30 [ 71.144624][ T8989] do_vfs_ioctl+0x977/0x14e0 [ 71.144632][ T8989] ? compat_ioctl_preallocate+0x220/0x220 [ 71.144639][ T8989] ? kmem_cache_free+0x26b/0x320 [ 71.144647][ T8989] ? putname+0xf4/0x130 [ 71.144653][ T8989] ? do_sys_open+0x31d/0x5d0 [ 71.144661][ T8989] ? tomoyo_file_ioctl+0x23/0x30 [ 71.144668][ T8989] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 71.144676][ T8989] ? security_file_ioctl+0x8d/0xc0 [ 71.144683][ T8989] ksys_ioctl+0xab/0xd0 [ 71.144690][ T8989] __x64_sys_ioctl+0x73/0xb0 [ 71.144703][ T8989] do_syscall_64+0xfa/0x790 [ 71.144713][ T8989] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 71.144718][ T8989] RIP: 0033:0x440219 [ 71.144725][ T8989] 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 [ 71.144728][ T8989] RSP: 002b:00007ffe3702aa48 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 71.144735][ T8989] RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440219 [ 71.144739][ T8989] RDX: 00000000200002c0 RSI: 000000000000560a RDI: 0000000000000004 [ 71.144743][ T8989] RBP: 00000000006ca018 R08: 0000000000000001 R09: 00000000004002c8 [ 71.144747][ T8989] R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000401b00 [ 71.144751][ T8989] R13: 0000000000401b90 R14: 0000000000000000 R15: 0000000000000000 [ 71.146108][ T8989] Kernel Offset: disabled [ 72.253722][ T8989] Rebooting in 86400 seconds..