From 4b259fc4a8a12dcd0ffd670877a7a1ca2ab0f3e3 Mon Sep 17 00:00:00 2001
From: Ma Shimiao <mashimiao.fnst@cn.fujitsu.com>
Date: Tue, 12 Dec 2017 17:39:10 +0800
Subject: [PATCH] dm log writes: fix max length used for kstrndup
Git-commit: 4b259fc4a8a12dcd0ffd670877a7a1ca2ab0f3e3
Patch-mainline: v4.16-rc1
References: bsc#1093023
If source string is longer than max, kstrndup will allocate max+1
space. So make sure the result will not exceed max.
Signed-off-by: Ma Shimiao <mashimiao.fnst@cn.fujitsu.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Coly Li <colyli@suse.de>
---
drivers/md/dm-log-writes.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/md/dm-log-writes.c b/drivers/md/dm-log-writes.c
index 189badbeddaf..3362d866793b 100644
--- a/drivers/md/dm-log-writes.c
+++ b/drivers/md/dm-log-writes.c
@@ -594,7 +594,7 @@ static int log_mark(struct log_writes_c *lc, char *data)
return -ENOMEM;
}
- block->data = kstrndup(data, maxsize, GFP_KERNEL);
+ block->data = kstrndup(data, maxsize - 1, GFP_KERNEL);
if (!block->data) {
DMERR("Error copying mark data");
kfree(block);
--
2.16.3