Re: [PATCH] jfs: Fix array-index-out-of-bounds in diFree

Jeongjun Park
2024-04-26T01:42:47Z

Matthew Wilcox wrote:
> In your earlier mail, you said the large value was found in db_agl2size.
> If the problem is in agstart then diRead() is the right place to check it.

Oh, I was so distracted last time that I wrote the explanation
incorrectly. I'm sorry.

To explain it accurately, if you pass a very large value to agstart
and set the value passed to db_agl2size to be small, it can be
manipulated so that a value greater than MAXAG is output when the
"agstart >> db_agl2size" operation is performed.
This results in an out-of-bounds vulnerability.

And the final patch before is the one that fixes diRead().

Thanks.