linux-ext4 - Re: [PATCH] ext4: do not use extent after put

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Message-ID: <20201029041451.GT5691@mit.edu>
Date:   Thu, 29 Oct 2020 00:14:51 -0400
From:   "Theodore Y. Ts'o" <tytso@....edu>
To:     yangerkun <yangerkun@...wei.com>
Cc:     jack@...e.com, adilger@...ger.ca, linux-ext4@...r.kernel.org
Subject: Re: [PATCH] ext4: do not use extent after put_bh

On Wed, Oct 28, 2020 at 01:56:17PM +0800, 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.
> 
> Signed-off-by: yangerkun <yangerkun@...wei.com>

Good catch!

Thanks, applied.

					- Ted