fsck.f2fs: sanity check blk_off for summary block entries

crafted malicious f2fs partition can fill an out of bound blk_off,
which cause overflow when accessing summary block entries.

Bug: 36394556

Change-Id: Icf0dfa7803a377c140b7d30cd7037c6058a4f8ea
Signed-off-by: Jin Qian <jinqian@google.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
1 file changed