CVE-2022-49763: In the Linux kernel, the following vulnerability has been resolved:  ntfs: fix use-after-free in ntfs_attr_find()  Patch series "ntfs: fix bugs about Attribute", v2.  This patchset fixes three bugs relative to Attribute in record:  Patch 1 adds a sanity check to ensure that, attrs_offset field in first mft record loading from disk is within bounds.  Patch 2 moves the ATTR_RECORD's bounds checking earlier, to avoid dereferencing ATTR_RECORD before checking this ATTR_RECORD is within bounds.  Patch 3 adds an overflow checking to avoid possible forever loop in ntfs_attr_find().  Without patch 1 and patch 2, the kernel triggersa KASAN use-after-free detection as reported by Syzkaller.  Although one of patch 1 or patch 2 can fix this, we still need both of them.  Because patch 1 fixes the root cause, and patch 2 not only fixes the direct cause, but also fixes the potential out-of-bounds bug.   This patch (of 3):  Syzkaller reported use-after-free read as follows: ================================================================== BUG: KASAN: use-after-free in ntfs_attr_find+0xc02/0xce0 fs/ntfs/attrib.c:597 Read of size 2 at addr ffff88807e352009 by task syz-executor153/3607  [...] Call Trace:  <TASK>  __dump_stack lib/dump_stack.c:88 [inline]  dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106  print_address_description mm/kasan/report.c:317 [inline]  print_report.cold+0x2ba/0x719 mm/kasan/report.c:433  kasan_report+0xb1/0x1e0 mm/kasan/report.c:495  ntfs_attr_find+0xc02/0xce0 fs/ntfs/attrib.c:597  ntfs_attr_lookup+0x1056/0x2070 fs/ntfs/attrib.c:1193  ntfs_read_inode_mount+0x89a/0x2580 fs/ntfs/inode.c:1845  ntfs_fill_super+0x1799/0x9320 fs/ntfs/super.c:2854  mount_bdev+0x34d/0x410 fs/super.c:1400  legacy_get_tree+0x105/0x220 fs/fs_context.c:610  vfs_get_tree+0x89/0x2f0 fs/super.c:1530  do_new_mount fs/namespace.c:3040 [inline]  path_mount+0x1326/0x1e20 fs/namespace.c:3370  do_mount fs/namespace.c:3383 [inline]  __do_sys_mount fs/namespace.c:3591 [inline]  __se_sys_mount fs/namespace.c:3568 [inline]  __x64_sys_mount+0x27f/0x300 fs/namespace.c:3568  do_syscall_x64 arch/x86/entry/common.c:50 [inline]  do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80  entry_SYSCALL_64_after_hwframe+0x63/0xcd  [...]  </TASK>  The buggy address belongs to the physical page: page:ffffea0001f8d400 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7e350 head:ffffea0001f8d400 order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 0000000000000000 dead000000000122 ffff888011842140 raw: 0000000000000000 0000000000040004 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address:  ffff88807e351f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc  ffff88807e351f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88807e352000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb                       ^  ffff88807e352080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb  ffff88807e352100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================  Kernel will loads $MFT/$DATA's first mft record in ntfs_read_inode_mount().  Yet the problem is that after loading, kernel doesn't check whether attrs_offset field is a valid value.  To be more specific, if attrs_offset field is larger than bytes_allocated field, then it may trigger the out-of-bounds read bug(reported as use-after-free bug) in ntfs_attr_find(), when kernel tries to access the corresponding mft record's attribute.  This patch solves it by adding the sanity check between attrs_offset field and bytes_allocated field, after loading the first mft record.