From: Xi Wang <xi.wang@gmail.com>
Date: Fri, 4 Jan 2013 08:22:57 +0000 (-0500)
Subject: nfs: fix null checking in nfs_get_option_str()
X-Git-Tag: v3.2.37~25
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=66ebe467a6dbbd0b3917ef6ad1bd4930f9b8185d;p=thirdparty%2Fkernel%2Fstable.git

nfs: fix null checking in nfs_get_option_str()

commit e25fbe380c4e3c09afa98bcdcd9d3921443adab8 upstream.

The following null pointer check is broken.

	*option = match_strdup(args);
	return !option;

The pointer `option' must be non-null, and thus `!option' is always false.
Use `!*option' instead.

The bug was introduced in commit c5cb09b6f8 ("Cleanup: Factor out some
cut-and-paste code.").

Signed-off-by: Xi Wang <xi.wang@gmail.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---

diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index 81503449f78d8..19438987bbe41 100644
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -1057,7 +1057,7 @@ static int nfs_get_option_str(substring_t args[], char **option)
 {
 	kfree(*option);
 	*option = match_strdup(args);
-	return !option;
+	return !*option;
 }
 
 static int nfs_get_option_ul(substring_t args[], unsigned long *option)