From: Ye Bin <yebin10@huawei.com>
Date: Tue, 13 Jul 2021 02:27:28 +0000 (+0800)
Subject: ext4: fix potential uninitialized access to retval in kmmpd
X-Git-Tag: v5.14-rc5~13^2~2
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b66541422824cf6cf20e9a35112e9cb5d82cdf62;p=thirdparty%2Fkernel%2Flinux.git

ext4: fix potential uninitialized access to retval in kmmpd

if (!ext4_has_feature_mmp(sb)) then retval can be unitialized before
we jump to the wait_to_exit label.

Fixes: 61bb4a1c417e ("ext4: fix possible UAF when remounting r/o a mmp-protected file system")
Signed-off-by: Ye Bin <yebin10@huawei.com>
Link: https://lore.kernel.org/r/20210713022728.2533770-1-yebin10@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
---

diff --git a/fs/ext4/mmp.c b/fs/ext4/mmp.c
index bc364c119af6a..cebea4270817e 100644
--- a/fs/ext4/mmp.c
+++ b/fs/ext4/mmp.c
@@ -138,7 +138,7 @@ static int kmmpd(void *data)
 	unsigned mmp_check_interval;
 	unsigned long last_update_time;
 	unsigned long diff;
-	int retval;
+	int retval = 0;
 
 	mmp_block = le64_to_cpu(es->s_mmp_block);
 	mmp = (struct mmp_struct *)(bh->b_data);