[ 41.832554] audit: type=1800 audit(1579602251.228:30): pid=7969 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 periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. Starting mcstransd: [....] Starting file context maintaining daemon: restorecond[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 47.341257] kauditd_printk_skb: 4 callbacks suppressed [ 47.341272] audit: type=1400 audit(1579602256.758:35): avc: denied { map } for pid=8142 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 '10.128.0.126' (ECDSA) to the list of known hosts. executing program executing program executing program executing program executing program executing program executing program [ 54.162700] audit: type=1400 audit(1579602263.578:36): avc: denied { map } for pid=8154 comm="syz-executor105" path="/root/syz-executor105205136" dev="sda1" ino=16483 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1 [ 54.234397] ================================================================== [ 54.234434] BUG: KASAN: use-after-free in con_shutdown+0x85/0x90 [ 54.234446] Write of size 8 at addr ffff888094bc5848 by task syz-executor105/8165 [ 54.234450] [ 54.234464] CPU: 0 PID: 8165 Comm: syz-executor105 Not tainted 4.19.97-syzkaller #0 [ 54.234473] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 54.234477] Call Trace: [ 54.234495] dump_stack+0x197/0x210 [ 54.234514] ? con_shutdown+0x85/0x90 [ 54.234533] print_address_description.cold+0x7c/0x20d [ 54.234550] ? con_shutdown+0x85/0x90 [ 54.234565] kasan_report.cold+0x8c/0x2ba [ 54.234582] ? set_palette+0x1c0/0x1c0 [ 54.234601] __asan_report_store8_noabort+0x17/0x20 [ 54.234616] con_shutdown+0x85/0x90 [ 54.234631] release_tty+0xe4/0x4d0 [ 54.234649] tty_release_struct+0x3c/0x50 [ 54.234665] tty_release+0xbcb/0xe90 [ 54.234687] ? tty_release_struct+0x50/0x50 [ 54.234701] __fput+0x2dd/0x8b0 [ 54.234724] ____fput+0x16/0x20 [ 54.234745] task_work_run+0x145/0x1c0 [ 54.234765] do_exit+0xc1f/0x30d0 [ 54.234785] ? get_signal+0x384/0x1fc0 [ 54.234804] ? mm_update_next_owner+0x660/0x660 [ 54.234826] ? _raw_spin_unlock_irq+0x28/0x90 [ 54.234839] ? get_signal+0x384/0x1fc0 [ 54.234852] ? _raw_spin_unlock_irq+0x28/0x90 [ 54.234871] do_group_exit+0x135/0x370 [ 54.234888] get_signal+0x3ec/0x1fc0 [ 54.234915] ? __fget+0x340/0x540 [ 54.234942] do_signal+0x95/0x1960 [ 54.234955] ? tty_vhangup+0x30/0x30 [ 54.234972] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 54.234985] ? do_vfs_ioctl+0x120/0x1380 [ 54.234998] ? selinux_file_ioctl+0x46f/0x5e0 [ 54.235014] ? setup_sigcontext+0x7d0/0x7d0 [ 54.235027] ? ioctl_preallocate+0x210/0x210 [ 54.235037] ? selinux_file_mprotect+0x620/0x620 [ 54.235068] ? __x64_sys_futex+0x40d/0x590 [ 54.235083] ? exit_to_usermode_loop+0x43/0x2c0 [ 54.235094] ? do_syscall_64+0x53d/0x620 [ 54.235105] ? exit_to_usermode_loop+0x43/0x2c0 [ 54.235119] ? lockdep_hardirqs_on+0x415/0x5d0 [ 54.235131] ? trace_hardirqs_on+0x67/0x220 [ 54.235146] exit_to_usermode_loop+0x244/0x2c0 [ 54.235161] do_syscall_64+0x53d/0x620 [ 54.235174] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 54.235183] RIP: 0033:0x4467a9 [ 54.235194] Code: e8 0c e8 ff ff 48 83 c4 18 c3 0f 1f 80 00 00 00 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 07 fc ff c3 66 2e 0f 1f 84 00 00 00 00 [ 54.235200] RSP: 002b:00007fed7cda6db8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca [ 54.235211] RAX: fffffffffffffe00 RBX: 00000000006dbc28 RCX: 00000000004467a9 [ 54.235217] RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00000000006dbc28 [ 54.235223] RBP: 00000000006dbc20 R08: 0000000000000000 R09: 0000000000000000 [ 54.235229] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dbc2c [ 54.235235] R13: 00007fffb3fb91af R14: 00007fed7cda79c0 R15: 000000000000002d [ 54.235250] [ 54.235255] Allocated by task 8165: [ 54.235265] save_stack+0x45/0xd0 [ 54.235274] kasan_kmalloc+0xce/0xf0 [ 54.235283] kmem_cache_alloc_trace+0x152/0x760 [ 54.235299] vc_allocate+0x1f5/0x760 [ 54.235309] con_install+0x52/0x410 [ 54.235319] tty_init_dev+0xf7/0x460 [ 54.235329] tty_open+0x4bf/0xb70 [ 54.235337] chrdev_open+0x245/0x6b0 [ 54.235345] do_dentry_open+0x4c3/0x1210 [ 54.235353] vfs_open+0xa0/0xd0 [ 54.235361] path_openat+0x10d7/0x45e0 [ 54.235369] do_filp_open+0x1a1/0x280 [ 54.235377] do_sys_open+0x3fe/0x550 [ 54.235386] __x64_sys_open+0x7e/0xc0 [ 54.235402] do_syscall_64+0xfd/0x620 [ 54.235412] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 54.235415] [ 54.235419] Freed by task 8169: [ 54.235428] save_stack+0x45/0xd0 [ 54.235438] __kasan_slab_free+0x102/0x150 [ 54.235448] kasan_slab_free+0xe/0x10 [ 54.235456] kfree+0xcf/0x220 [ 54.235464] vt_disallocate_all+0x2bd/0x3e0 [ 54.235472] vt_ioctl+0xc38/0x2530 [ 54.235481] tty_ioctl+0x7f3/0x1510 [ 54.235490] do_vfs_ioctl+0xd5f/0x1380 [ 54.235498] ksys_ioctl+0xab/0xd0 [ 54.235507] __x64_sys_ioctl+0x73/0xb0 [ 54.235517] do_syscall_64+0xfd/0x620 [ 54.235527] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 54.235530] [ 54.235537] The buggy address belongs to the object at ffff888094bc5740 [ 54.235537] which belongs to the cache kmalloc-2048 of size 2048 [ 54.235546] The buggy address is located 264 bytes inside of [ 54.235546] 2048-byte region [ffff888094bc5740, ffff888094bc5f40) [ 54.235549] The buggy address belongs to the page: [ 54.235558] page:ffffea000252f100 count:1 mapcount:0 mapping:ffff88812c31cc40 index:0x0 compound_mapcount: 0 [ 54.235568] flags: 0xfffe0000008100(slab|head) [ 54.235583] raw: 00fffe0000008100 ffffea00023e9e88 ffffea000238e108 ffff88812c31cc40 [ 54.235595] raw: 0000000000000000 ffff888094bc4640 0000000100000003 0000000000000000 [ 54.235599] page dumped because: kasan: bad access detected [ 54.235601] [ 54.235604] Memory state around the buggy address: [ 54.235612] ffff888094bc5700: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb [ 54.235620] ffff888094bc5780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 54.235628] >ffff888094bc5800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 54.235632] ^ [ 54.235640] ffff888094bc5880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 54.235647] ffff888094bc5900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 54.235651] ================================================================== [ 54.235654] Disabling lock debugging due to kernel taint [ 54.235691] Kernel panic - not syncing: panic_on_warn set ... [ 54.235691] [ 54.235702] CPU: 0 PID: 8165 Comm: syz-executor105 Tainted: G B 4.19.97-syzkaller #0 [ 54.235707] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 54.235710] Call Trace: [ 54.235721] dump_stack+0x197/0x210 [ 54.235732] ? con_shutdown+0x85/0x90 [ 54.235740] panic+0x26a/0x50e [ 54.235749] ? __warn_printk+0xf3/0xf3 [ 54.235759] ? con_shutdown+0x85/0x90 [ 54.235772] ? trace_hardirqs_on+0x5e/0x220 [ 54.235781] ? trace_hardirqs_on+0x5e/0x220 [ 54.235793] ? con_shutdown+0x85/0x90 [ 54.235804] kasan_end_report+0x47/0x4f [ 54.235815] kasan_report.cold+0xa9/0x2ba [ 54.235826] ? set_palette+0x1c0/0x1c0 [ 54.235838] __asan_report_store8_noabort+0x17/0x20 [ 54.235848] con_shutdown+0x85/0x90 [ 54.235858] release_tty+0xe4/0x4d0 [ 54.235870] tty_release_struct+0x3c/0x50 [ 54.235880] tty_release+0xbcb/0xe90 [ 54.235894] ? tty_release_struct+0x50/0x50 [ 54.235904] __fput+0x2dd/0x8b0 [ 54.235929] ____fput+0x16/0x20 [ 54.235941] task_work_run+0x145/0x1c0 [ 54.235954] do_exit+0xc1f/0x30d0 [ 54.235969] ? get_signal+0x384/0x1fc0 [ 54.235985] ? mm_update_next_owner+0x660/0x660 [ 54.236001] ? _raw_spin_unlock_irq+0x28/0x90 [ 54.236013] ? get_signal+0x384/0x1fc0 [ 54.236024] ? _raw_spin_unlock_irq+0x28/0x90 [ 54.236036] do_group_exit+0x135/0x370 [ 54.236047] get_signal+0x3ec/0x1fc0 [ 54.236059] ? __fget+0x340/0x540 [ 54.236073] do_signal+0x95/0x1960 [ 54.236082] ? tty_vhangup+0x30/0x30 [ 54.236093] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 54.236102] ? do_vfs_ioctl+0x120/0x1380 [ 54.236110] ? selinux_file_ioctl+0x46f/0x5e0 [ 54.236122] ? setup_sigcontext+0x7d0/0x7d0 [ 54.236131] ? ioctl_preallocate+0x210/0x210 [ 54.236140] ? selinux_file_mprotect+0x620/0x620 [ 54.236155] ? __x64_sys_futex+0x40d/0x590 [ 54.236167] ? exit_to_usermode_loop+0x43/0x2c0 [ 54.236177] ? do_syscall_64+0x53d/0x620 [ 54.236188] ? exit_to_usermode_loop+0x43/0x2c0 [ 54.236199] ? lockdep_hardirqs_on+0x415/0x5d0 [ 54.236209] ? trace_hardirqs_on+0x67/0x220 [ 54.236222] exit_to_usermode_loop+0x244/0x2c0 [ 54.236234] do_syscall_64+0x53d/0x620 [ 54.236246] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 54.236252] RIP: 0033:0x4467a9 [ 54.236262] Code: e8 0c e8 ff ff 48 83 c4 18 c3 0f 1f 80 00 00 00 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 07 fc ff c3 66 2e 0f 1f 84 00 00 00 00 [ 54.236267] RSP: 002b:00007fed7cda6db8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca [ 54.236276] RAX: fffffffffffffe00 RBX: 00000000006dbc28 RCX: 00000000004467a9 [ 54.236282] RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00000000006dbc28 [ 54.236288] RBP: 00000000006dbc20 R08: 0000000000000000 R09: 0000000000000000 [ 54.236293] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dbc2c [ 54.236299] R13: 00007fffb3fb91af R14: 00007fed7cda79c0 R15: 000000000000002d [ 54.238001] Kernel Offset: disabled