[ 43.423518] audit: type=1800 audit(1581840101.241:30): pid=8048 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:kernel_t:s0 op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 Starting mcstransd: [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting file context maintaining daemon: restorecond[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 49.168289] kauditd_printk_skb: 4 callbacks suppressed [ 49.168303] audit: type=1400 audit(1581840107.031:35): avc: denied { map } for pid=8222 comm="bash" path="/bin/bash" dev="sda1" ino=1457 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1 Warning: Permanently added '10.128.0.65' (ECDSA) to the list of known hosts. executing program executing program executing program executing program executing program executing program executing program executing program [ 72.112258] audit: type=1400 audit(1581840129.971:36): avc: denied { map } for pid=8234 comm="syz-executor381" path="/root/syz-executor381678275" dev="sda1" ino=1426 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1 [ 72.176662] ================================================================== [ 72.176694] BUG: KASAN: use-after-free in con_shutdown+0x85/0x90 [ 72.176705] Write of size 8 at addr ffff88809f678148 by task syz-executor381/8241 [ 72.176707] [ 72.176720] CPU: 0 PID: 8241 Comm: syz-executor381 Not tainted 4.19.104-syzkaller #0 [ 72.176726] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 72.176730] Call Trace: [ 72.176746] dump_stack+0x197/0x210 [ 72.176760] ? con_shutdown+0x85/0x90 [ 72.176778] print_address_description.cold+0x7c/0x20d [ 72.176794] ? con_shutdown+0x85/0x90 [ 72.176817] kasan_report.cold+0x8c/0x2ba [ 72.176833] ? set_palette+0x1c0/0x1c0 [ 72.176852] __asan_report_store8_noabort+0x17/0x20 [ 72.176866] con_shutdown+0x85/0x90 [ 72.176879] release_tty+0xe4/0x4d0 [ 72.176897] tty_release_struct+0x3c/0x50 [ 72.176912] tty_release+0xbcb/0xe90 [ 72.176934] ? tty_release_struct+0x50/0x50 [ 72.176950] __fput+0x2dd/0x8b0 [ 72.176972] ____fput+0x16/0x20 [ 72.176986] task_work_run+0x145/0x1c0 [ 72.177007] do_exit+0xc1f/0x30d0 [ 72.177030] ? mm_update_next_owner+0x660/0x660 [ 72.177046] ? up_read+0x1a/0x110 [ 72.177060] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 72.177074] ? __do_page_fault+0x484/0xe90 [ 72.177095] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 72.177110] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 72.177126] do_group_exit+0x135/0x370 [ 72.177142] __x64_sys_exit_group+0x44/0x50 [ 72.177159] do_syscall_64+0xfd/0x620 [ 72.177180] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 72.177192] RIP: 0033:0x43ff38 [ 72.177207] Code: 00 00 be 3c 00 00 00 eb 19 66 0f 1f 84 00 00 00 00 00 48 89 d7 89 f0 0f 05 48 3d 00 f0 ff ff 77 21 f4 48 89 d7 44 89 c0 0f 05 <48> 3d 00 f0 ff ff 76 e0 f7 d8 64 41 89 01 eb d8 0f 1f 84 00 00 00 [ 72.177215] RSP: 002b:00007ffffd39a5b8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 72.177229] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043ff38 [ 72.177237] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 72.177246] RBP: 00000000004bf950 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 72.177255] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 [ 72.177263] R13: 00000000006d2180 R14: 0000000000000000 R15: 0000000000000000 [ 72.177283] [ 72.177289] Allocated by task 8241: [ 72.177304] save_stack+0x45/0xd0 [ 72.177316] kasan_kmalloc+0xce/0xf0 [ 72.177328] kmem_cache_alloc_trace+0x152/0x760 [ 72.177340] vc_allocate+0x1f5/0x760 [ 72.177352] con_install+0x52/0x410 [ 72.177365] tty_init_dev+0xf7/0x460 [ 72.177376] tty_open+0x4bf/0xb70 [ 72.177386] chrdev_open+0x245/0x6b0 [ 72.177398] do_dentry_open+0x4c3/0x1210 [ 72.177409] vfs_open+0xa0/0xd0 [ 72.177420] path_openat+0x10d8/0x44a0 [ 72.177431] do_filp_open+0x1a1/0x280 [ 72.177442] do_sys_open+0x3fe/0x550 [ 72.177453] __x64_sys_open+0x7e/0xc0 [ 72.177466] do_syscall_64+0xfd/0x620 [ 72.177480] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 72.177483] [ 72.177489] Freed by task 8242: [ 72.177507] save_stack+0x45/0xd0 [ 72.177520] __kasan_slab_free+0x102/0x150 [ 72.177533] kasan_slab_free+0xe/0x10 [ 72.177544] kfree+0xcf/0x220 [ 72.177558] vt_disallocate_all+0x2bd/0x3e0 [ 72.177571] vt_ioctl+0xc38/0x2530 [ 72.177582] tty_ioctl+0x7f3/0x1510 [ 72.177595] do_vfs_ioctl+0xd5f/0x1380 [ 72.177606] ksys_ioctl+0xab/0xd0 [ 72.177617] __x64_sys_ioctl+0x73/0xb0 [ 72.177630] do_syscall_64+0xfd/0x620 [ 72.177643] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 72.177647] [ 72.177657] The buggy address belongs to the object at ffff88809f678040 [ 72.177657] which belongs to the cache kmalloc-2048 of size 2048 [ 72.177669] The buggy address is located 264 bytes inside of [ 72.177669] 2048-byte region [ffff88809f678040, ffff88809f678840) [ 72.177674] The buggy address belongs to the page: [ 72.177686] page:ffffea00027d9e00 count:1 mapcount:0 mapping:ffff88812c31cc40 index:0x0 compound_mapcount: 0 [ 72.177700] flags: 0xfffe0000008100(slab|head) [ 72.177719] raw: 00fffe0000008100 ffffea0002083d88 ffffea00027a1b88 ffff88812c31cc40 [ 72.177733] raw: 0000000000000000 ffff88809f678040 0000000100000003 0000000000000000 [ 72.177739] page dumped because: kasan: bad access detected [ 72.177742] [ 72.177747] Memory state around the buggy address: [ 72.177758] ffff88809f678000: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb [ 72.177769] ffff88809f678080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 72.177779] >ffff88809f678100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 72.177785] ^ [ 72.177796] ffff88809f678180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 72.177812] ffff88809f678200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 72.177817] ================================================================== [ 72.177822] Disabling lock debugging due to kernel taint [ 72.177853] Kernel panic - not syncing: panic_on_warn set ... [ 72.177853] [ 72.177866] CPU: 0 PID: 8241 Comm: syz-executor381 Tainted: G B 4.19.104-syzkaller #0 [ 72.177874] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 72.177878] Call Trace: [ 72.177892] dump_stack+0x197/0x210 [ 72.177906] ? con_shutdown+0x85/0x90 [ 72.177918] panic+0x26a/0x50e [ 72.177928] ? __warn_printk+0xf3/0xf3 [ 72.177939] ? con_shutdown+0x85/0x90 [ 72.177958] ? trace_hardirqs_on+0x5e/0x220 [ 72.177969] ? trace_hardirqs_on+0x5e/0x220 [ 72.177981] ? con_shutdown+0x85/0x90 [ 72.177994] kasan_end_report+0x47/0x4f [ 72.178008] kasan_report.cold+0xa9/0x2ba [ 72.178021] ? set_palette+0x1c0/0x1c0 [ 72.178035] __asan_report_store8_noabort+0x17/0x20 [ 72.178048] con_shutdown+0x85/0x90 [ 72.178061] release_tty+0xe4/0x4d0 [ 72.178074] tty_release_struct+0x3c/0x50 [ 72.178087] tty_release+0xbcb/0xe90 [ 72.178103] ? tty_release_struct+0x50/0x50 [ 72.178116] __fput+0x2dd/0x8b0 [ 72.178133] ____fput+0x16/0x20 [ 72.178144] task_work_run+0x145/0x1c0 [ 72.178158] do_exit+0xc1f/0x30d0 [ 72.178176] ? mm_update_next_owner+0x660/0x660 [ 72.178190] ? up_read+0x1a/0x110 [ 72.178203] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 72.178216] ? __do_page_fault+0x484/0xe90 [ 72.178234] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 72.178247] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 72.178260] do_group_exit+0x135/0x370 [ 72.178274] __x64_sys_exit_group+0x44/0x50 [ 72.178287] do_syscall_64+0xfd/0x620 [ 72.178304] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 72.178313] RIP: 0033:0x43ff38 [ 72.178326] Code: 00 00 be 3c 00 00 00 eb 19 66 0f 1f 84 00 00 00 00 00 48 89 d7 89 f0 0f 05 48 3d 00 f0 ff ff 77 21 f4 48 89 d7 44 89 c0 0f 05 <48> 3d 00 f0 ff ff 76 e0 f7 d8 64 41 89 01 eb d8 0f 1f 84 00 00 00 [ 72.178333] RSP: 002b:00007ffffd39a5b8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 72.178344] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043ff38 [ 72.178351] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 72.178357] RBP: 00000000004bf950 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 72.178363] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 [ 72.178369] R13: 00000000006d2180 R14: 0000000000000000 R15: 0000000000000000 [ 72.179800] Kernel Offset: disabled [ 72.869726] Rebooting in 86400 seconds..