From: Christoph Hellwig <hch@infradead.org>
To: Zhang Yi <yi.zhang@huawei.com>
Cc: linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org,
tytso@mit.edu, adilger.kernel@dilger.ca, jack@suse.cz,
yukuai3@huawei.com
Subject: Re: [RFC PATCH v2 7/7] ext4: fix race between blkdev_releasepage() and ext4_put_super()
Date: Thu, 15 Apr 2021 15:52:35 +0100 [thread overview]
Message-ID: <20210415145235.GD2069063@infradead.org> (raw)
In-Reply-To: <20210414134737.2366971-8-yi.zhang@huawei.com>
On Wed, Apr 14, 2021 at 09:47:37PM +0800, Zhang Yi wrote:
> There still exist a use after free issue when accessing the journal
> structure and ext4_sb_info structure on freeing bdev buffers in
> bdev_try_to_free_page(). The problem is bdev_try_to_free_page() could be
> raced by ext4_put_super(), it dose freeing sb->s_fs_info and
> sbi->s_journal while release page progress are still accessing them.
> So it could end up trigger use-after-free or NULL pointer dereference.
I think the right fix is to not even call into ->bdev_try_to_free_page
unless the superblock is active.
next prev parent reply other threads:[~2021-04-15 14:54 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-14 13:47 [RFC PATCH v2 0/7] ext4, jbd2: fix 3 issues about bdev_try_to_free_page() Zhang Yi
2021-04-14 13:47 ` [RFC PATCH v2 1/7] jbd2: remove the out label in __jbd2_journal_remove_checkpoint() Zhang Yi
2021-04-21 10:01 ` Jan Kara
2021-04-14 13:47 ` [RFC PATCH v2 2/7] jbd2: ensure abort the journal if detect IO error when writing original buffer back Zhang Yi
2021-04-21 13:20 ` Jan Kara
2021-04-14 13:47 ` [RFC PATCH v2 3/7] jbd2: don't abort the journal when freeing buffers Zhang Yi
2021-04-21 13:23 ` Jan Kara
2021-04-14 13:47 ` [RFC PATCH v2 4/7] jbd2: do not free buffers in jbd2_journal_try_to_free_buffers() Zhang Yi
2021-04-15 14:46 ` Christoph Hellwig
2021-04-14 13:47 ` [RFC PATCH v2 5/7] ext4: use RCU to protect accessing superblock in blkdev_releasepage() Zhang Yi
2021-04-15 14:48 ` Christoph Hellwig
2021-04-14 13:47 ` [RFC PATCH v2 6/7] fs: introduce a usage count into the superblock Zhang Yi
2021-04-15 14:40 ` Christoph Hellwig
2021-04-16 8:00 ` Zhang Yi
2021-04-14 13:47 ` [RFC PATCH v2 7/7] ext4: fix race between blkdev_releasepage() and ext4_put_super() Zhang Yi
2021-04-15 14:52 ` Christoph Hellwig [this message]
2021-04-16 8:00 ` Zhang Yi
2021-04-20 13:08 ` Christoph Hellwig
2021-04-21 13:46 ` Jan Kara
2021-04-21 16:57 ` Theodore Ts'o
2021-04-22 9:04 ` Jan Kara
2021-04-23 11:39 ` Zhang Yi
2021-04-23 16:06 ` Jan Kara
2021-04-23 14:40 ` Theodore Ts'o
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=20210415145235.GD2069063@infradead.org \
--to=hch@infradead.org \
--cc=adilger.kernel@dilger.ca \
--cc=jack@suse.cz \
--cc=linux-ext4@vger.kernel.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=tytso@mit.edu \
--cc=yi.zhang@huawei.com \
--cc=yukuai3@huawei.com \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.