Re: [PATCH] ext4: do not use extent after put_bh

Ritesh Harjani
2020-10-29T16:09:04Z

On 10/28/20 11:26 AM, yangerkun wrote:
> ext4_ext_search_right will read more extent block and call put_bh after
> we get the information we need. However ret_ex will break this and may
> cause use-after-free once pagecache has been freed. Fix it by dup the
> extent we need.

It would be good if we have a test case to reproduce it. Do you?
Ideally it should go in fstests, if you have some way to forcefully
reproduce it/simulate it. Let me know, if needed, I can as well help to
get those into fstests.

-ritesh