linux-kernel - ext4: avoid drop reference to iloc.bh twice

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-Id: <1555576278-3917-1-git-send-email-bianpan2016@163.com>
Date:   Thu, 18 Apr 2019 16:31:18 +0800
From:   Pan Bian <bianpan2016@....com>
To:     "Theodore Ts'o" <tytso@....edu>,
        Andreas Dilger <adilger.kernel@...ger.ca>
Cc:     linux-ext4@...r.kernel.org, linux-kernel@...r.kernel.org,
        Pan Bian <bianpan2016@....com>
Subject: ext4: avoid drop reference to iloc.bh twice

The reference to iloc.bh has been dropped in ext4_mark_iloc_dirty.
However, the reference is dropped again if error occurs during
ext4_handle_dirty_metadata, which may result in use-after-free bugs.

Fixes: fb265c9cb49e("ext4: add ext4_sb_bread() to disambiguate ENOMEM
cases")

Signed-off-by: Pan Bian <bianpan2016@....com>
---
 fs/ext4/resize.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c
index e7ae26e..4d5c0fc 100644
--- a/fs/ext4/resize.c
+++ b/fs/ext4/resize.c
@@ -874,6 +874,7 @@ static int add_new_gdb(handle_t *handle, struct inode *inode,
 	err = ext4_handle_dirty_metadata(handle, NULL, gdb_bh);
 	if (unlikely(err)) {
 		ext4_std_error(sb, err);
+		iloc.bh = NULL;
 		goto errout;
 	}
 	brelse(dind);
-- 
2.7.4