ntfs: check overflow when iterating ATTR_RECORDs

Kernel iterates over ATTR_RECORDs in mft record in ntfs_attr_find(). 
Because the ATTR_RECORDs are next to each other, kernel can get the next
ATTR_RECORD from end address of current ATTR_RECORD, through current
ATTR_RECORD length field.

The problem is that during iteration, when kernel calculates the end
address of current ATTR_RECORD, kernel may trigger an integer overflow bug
in executing `a = (ATTR_RECORD*)((u8*)a + le32_to_cpu(a->length))`.  This
may wrap, leading to a forever iteration on 32bit systems.

This patch solves it by adding some checks on calculating end address
of current ATTR_RECORD during iteration.

Link: https://lkml.kernel.org/r/[email protected]
Link: https://lore.kernel.org/all/20220827105842.GM2030@kadam/
Signed-off-by: Hawkins Jiawei <[email protected]>
Suggested-by: Dan Carpenter <[email protected]>
Cc: Anton Altaparmakov <[email protected]>
Cc: chenxiaosong (A) <[email protected]>
Cc: syzkaller-bugs <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

0 files changed, 0 insertions, 0 deletions