linux-ext4 - [PATCH -next v2 5/6] ext4: avoid to double free s_mmp

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

Message-ID: <20210911090059.1876456-6-yebin10@huawei.com>
Date:   Sat, 11 Sep 2021 17:00:58 +0800
From:   Ye Bin <yebin10@...wei.com>
To:     <tytso@....edu>, <adilger.kernel@...ger.ca>,
        <linux-ext4@...r.kernel.org>
CC:     <linux-kernel@...r.kernel.org>, <jack@...e.cz>,
        Ye Bin <yebin10@...wei.com>
Subject: [PATCH -next v2 5/6] ext4: avoid to double free s_mmp_bh

If call read_mmp_block failed then s_mmp_bh will be freed in read_mmp_block.
Kmmpd wait to be killed, ext4_stop_mmpd stop kmmpd and also release s_mmp_bh.
To avoid double free, just set EXT4_SB(sb)->s_mmp_bh with NULL.

Signed-off-by: Ye Bin <yebin10@...wei.com>
---
 fs/ext4/mmp.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/fs/ext4/mmp.c b/fs/ext4/mmp.c
index 007bde3c12b8..a0d47a906faa 100644
--- a/fs/ext4/mmp.c
+++ b/fs/ext4/mmp.c
@@ -218,6 +218,7 @@ static int kmmpd(void *data)
 				ext4_error_err(sb, -retval,
 					       "error reading MMP data: %d",
 					       retval);
+				EXT4_SB(sb)->s_mmp_bh = NULL;
 				goto wait_to_exit;
 			}
 
-- 
2.31.1