[PATCH 5.13 020/175] ext4: fix potential uninitialized access to retval in kmmpd

[Greg Kroah-Hartman]

From: Ye Bin <yebin10@xxxxxxxxxx>

[ Upstream commit b66541422824cf6cf20e9a35112e9cb5d82cdf62 ]

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@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20210713022728.2533770-1-yebin10@xxxxxxxxxx
Signed-off-by: Theodore Ts'o <tytso@xxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 fs/ext4/mmp.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/ext4/mmp.c b/fs/ext4/mmp.c
index bc364c119af6..cebea4270817 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);
-- 
2.30.2