linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Chao Yu <yuchao0@huawei.com>
To: <jaegeuk@kernel.org>
Cc: <linux-f2fs-devel@lists.sourceforge.net>,
	<linux-kernel@vger.kernel.org>, <chao@kernel.org>,
	Chao Yu <yuchao0@huawei.com>
Subject: [PATCH] f2fs: fix potential use-after-free issue
Date: Thu, 23 Apr 2020 17:57:33 +0800	[thread overview]
Message-ID: <20200423095733.7733-1-yuchao0@huawei.com> (raw)

In error path of f2fs_read_multi_pages(), it should let last referrer
release decompress io context memory, otherwise, other referrer will
cause use-after-free issue.

Fixes: 4c8ff7095bef ("f2fs: support data compression")
Signed-off-by: Chao Yu <yuchao0@huawei.com>
---
 fs/f2fs/data.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 4adf28bdd022..48a622b95b76 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -2208,16 +2208,16 @@ int f2fs_read_multi_pages(struct compress_ctx *cc, struct bio **bio_ret,
 					page->index, for_write);
 			if (IS_ERR(bio)) {
 				ret = PTR_ERR(bio);
-				bio = NULL;
 				dic->failed = true;
 				if (refcount_sub_and_test(dic->nr_cpages - i,
-							&dic->ref))
+							&dic->ref)) {
 					f2fs_decompress_end_io(dic->rpages,
 							cc->cluster_size, true,
 							false);
-				f2fs_free_dic(dic);
+					f2fs_free_dic(dic);
+				}
 				f2fs_put_dnode(&dn);
-				*bio_ret = bio;
+				*bio_ret = NULL;
 				return ret;
 			}
 		}
-- 
2.18.0.rc1


                 reply	other threads:[~2020-04-23  9:57 UTC|newest]

Thread overview: [no followups] expand[flat|nested]  mbox.gz  Atom feed

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=20200423095733.7733-1-yuchao0@huawei.com \
    --to=yuchao0@huawei.com \
    --cc=chao@kernel.org \
    --cc=jaegeuk@kernel.org \
    --cc=linux-f2fs-devel@lists.sourceforge.net \
    --cc=linux-kernel@vger.kernel.org \
    /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 NNTP newsgroup(s).