From: Zhang Yi <yi.zhang@huaweicloud.com>
To: "Luis Henriques (SUSE)" <luis.henriques@linux.dev>
Cc: linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org,
Theodore Ts'o <tytso@mit.edu>, Andreas Dilger <adilger@dilger.ca>,
Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Subject: Re: [PATCH v2] ext4: fix infinite loop when replaying fast_commit
Date: Wed, 15 May 2024 20:27:54 +0800 [thread overview]
Message-ID: <1761896f-ce12-9aeb-616d-8451b1436943@huaweicloud.com> (raw)
In-Reply-To: <20240515082857.32730-1-luis.henriques@linux.dev>
On 2024/5/15 16:28, Luis Henriques (SUSE) wrote:
> When doing fast_commit replay an infinite loop may occur due to an
> uninitialized extent_status struct. ext4_ext_determine_insert_hole() does
> not detect the replay and calls ext4_es_find_extent_range(), which will
> return immediately without initializing the 'es' variable.
>
> Because 'es' contains garbage, an integer overflow may happen causing an
> infinite loop in this function, easily reproducible using fstest generic/039.
>
> This commit fixes this issue by unconditionally initializing the structure
> in function ext4_es_find_extent_range().
>
> Thanks to Zhang Yi, for figuring out the real problem!
>
> Fixes: 8016e29f4362 ("ext4: fast commit recovery path")
> Signed-off-by: Luis Henriques (SUSE) <luis.henriques@linux.dev>
Thanks for fixing this issue，looks good to me.
Reviewed-by: Zhang Yi <yi.zhang@huawei.com>
> ---
> fs/ext4/extents_status.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/fs/ext4/extents_status.c b/fs/ext4/extents_status.c
> index 4a00e2f019d9..3a53dbb85e15 100644
> --- a/fs/ext4/extents_status.c
> +++ b/fs/ext4/extents_status.c
> @@ -310,6 +310,8 @@ void ext4_es_find_extent_range(struct inode *inode,
> ext4_lblk_t lblk, ext4_lblk_t end,
> struct extent_status *es)
> {
> + es->es_lblk = es->es_len = es->es_pblk = 0;
> +
> if (EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY)
> return;
>
>
prev parent reply other threads:[~2024-05-15 12:27 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-05-15 8:28 [PATCH v2] ext4: fix infinite loop when replaying fast_commit Luis Henriques (SUSE)
2024-05-15 12:27 ` Zhang Yi [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1761896f-ce12-9aeb-616d-8451b1436943@huaweicloud.com \
--to=yi.zhang@huaweicloud.com \
--cc=adilger@dilger.ca \
--cc=harshadshirwadkar@gmail.com \
--cc=linux-ext4@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=luis.henriques@linux.dev \
--cc=tytso@mit.edu \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).