audit: type=1400 audit(1603218705.884:8): avc:  denied  { execmem } for  pid=6476 comm="syz-executor046" scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:system_r:kernel_t:s0 tclass=process permissive=1
ntfs: (device loop0): is_boot_sector_ntfs(): Invalid end of sector marker.
==================================================================
BUG: KASAN: use-after-free in ntfs_attr_find+0xa42/0xb70 fs/ntfs/attrib.c:613
Read of size 4 at addr ffff8880a459edbf by task syz-executor046/6476

CPU: 0 PID: 6476 Comm: syz-executor046 Not tainted 4.19.152-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x22c/0x33e lib/dump_stack.c:118
 print_address_description.cold+0x56/0x25c mm/kasan/report.c:256
 kasan_report_error.cold+0x66/0xb9 mm/kasan/report.c:354
 kasan_report mm/kasan/report.c:412 [inline]
 __asan_report_load_n_noabort+0x8b/0xa0 mm/kasan/report.c:443
 ntfs_attr_find+0xa42/0xb70 fs/ntfs/attrib.c:613
 ntfs_attr_lookup+0x1087/0x2060 fs/ntfs/attrib.c:1203
 ntfs_read_inode_mount+0x7e4/0x23b0 fs/ntfs/inode.c:1858
 ntfs_fill_super+0x1761/0x89d2 fs/ntfs/super.c:2871
 mount_bdev+0x2fc/0x3b0 fs/super.c:1158
 mount_fs+0xa3/0x318 fs/super.c:1261
 vfs_kern_mount.part.0+0x68/0x470 fs/namespace.c:961
 vfs_kern_mount fs/namespace.c:951 [inline]
 do_new_mount fs/namespace.c:2469 [inline]
 do_mount+0x51c/0x2f10 fs/namespace.c:2799
 ksys_mount+0xcf/0x130 fs/namespace.c:3015
 __do_sys_mount fs/namespace.c:3029 [inline]
 __se_sys_mount fs/namespace.c:3026 [inline]
 __x64_sys_mount+0xba/0x150 fs/namespace.c:3026
 do_syscall_64+0xf9/0x670 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x44995a
Code: b8 08 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 fd ad fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 da ad fb ff c3 66 0f 1f 84 00 00 00 00 00
RSP: 002b:00007fff9c966658 EFLAGS: 00000287 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fff9c9666b0 RCX: 000000000044995a
RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007fff9c966670
RBP: 00007fff9c966670 R08: 00007fff9c9666b0 R09: 00007fff00000015
R10: 0000000000000000 R11: 0000000000000287 R12: 000000000000013c
R13: 0000000000000004 R14: 0000000000000003 R15: 0000000000000003

Allocated by task 4725:
 kmem_cache_alloc+0x126/0x4a0 mm/slab.c:3559
 dup_mm kernel/fork.c:1279 [inline]
 copy_mm kernel/fork.c:1344 [inline]
 copy_process.part.0+0x2b24/0x7fb0 kernel/fork.c:1897
 copy_process kernel/fork.c:1694 [inline]
 _do_fork+0x22f/0x1020 kernel/fork.c:2207
 do_syscall_64+0xf9/0x670 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 6155:
 __cache_free mm/slab.c:3503 [inline]
 kmem_cache_free+0x7f/0x2b0 mm/slab.c:3765
 mmdrop include/linux/sched/mm.h:49 [inline]
 __mmput kernel/fork.c:1025 [inline]
 mmput+0x3b6/0x4a0 kernel/fork.c:1036
 exec_mmap fs/exec.c:1043 [inline]
 flush_old_exec fs/exec.c:1278 [inline]
 flush_old_exec+0x8ea/0x1c50 fs/exec.c:1253
 load_elf_binary+0x958/0x5010 fs/binfmt_elf.c:869
 search_binary_handler+0x177/0x570 fs/exec.c:1655
 exec_binprm fs/exec.c:1697 [inline]
 __do_execve_file+0x13a8/0x23c0 fs/exec.c:1819
 do_execveat_common fs/exec.c:1866 [inline]
 do_execve+0x35/0x50 fs/exec.c:1883
 __do_sys_execve fs/exec.c:1964 [inline]
 __se_sys_execve fs/exec.c:1959 [inline]
 __x64_sys_execve+0x7c/0xa0 fs/exec.c:1959
 do_syscall_64+0xf9/0x670 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff8880a459ec40
 which belongs to the cache mm_struct of size 1496
The buggy address is located 383 bytes inside of
 1496-byte region [ffff8880a459ec40, ffff8880a459f218)
The buggy address belongs to the page:
page:ffffea0002916780 count:1 mapcount:0 mapping:ffff88812c25a680 index:0xffff8880a459ec40 compound_mapcount: 0
flags: 0xfffe0000008100(slab|head)
raw: 00fffe0000008100 ffffea0002813788 ffffea000297c708 ffff88812c25a680
raw: ffff8880a459ec40 ffff8880a459e5c0 0000000100000001 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880a459ec80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880a459ed00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8880a459ed80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                        ^
 ffff8880a459ee00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880a459ee80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================