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From: Colin King <colin.king@canonical.com>
To: Masahiro Yamada <yamada.masahiro@socionext.com>,
	Michal Marek <michal.lkml@markovi.net>,
	linux-kbuild@vger.kernel.org
Cc: kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH][next] unicode: fix dereference of a potentially null pointer
Date: Fri, 26 Apr 2019 23:22:37 +0100	[thread overview]
Message-ID: <20190426222237.13209-1-colin.king@canonical.com> (raw)

From: Colin Ian King <colin.king@canonical.com>

The pointer 'tree' is deferenced when assigning pointer 'trie', however
trie is being null checked a few lines later, so it could potentially
be null. Fix the potential null pointer dereference by only dereferencing
it after it has been null checked.

Addresses-Coverity: ("Dereference before null check")
Fixes: b08fcacaaaf4 ("unicode: introduce UTF-8 character database")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
---
 scripts/mkutf8data.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/scripts/mkutf8data.c b/scripts/mkutf8data.c
index 12ce94b43be6..0563ba679bbb 100644
--- a/scripts/mkutf8data.c
+++ b/scripts/mkutf8data.c
@@ -2706,7 +2706,7 @@ static utf8leaf_t *utf8hangul(const char *str, unsigned char *hangul)
 static utf8leaf_t *utf8nlookup(struct tree *tree, unsigned char *hangul,
 			       const char *s, size_t len)
 {
-	utf8trie_t	*trie = utf8data + tree->index;
+	utf8trie_t	*trie;
 	int		offlen;
 	int		offset;
 	int		mask;
@@ -2716,6 +2716,7 @@ static utf8leaf_t *utf8nlookup(struct tree *tree, unsigned char *hangul,
 		return NULL;
 	if (len == 0)
 		return NULL;
+	trie = utf8data + tree->index;
 	node = 1;
 	while (node) {
 		offlen = (*trie & OFFLEN) >> OFFLEN_SHIFT;
-- 
2.20.1


WARNING: multiple messages have this Message-ID (diff)
From: Colin King <colin.king@canonical.com>
To: Masahiro Yamada <yamada.masahiro@socionext.com>,
	Michal Marek <michal.lkml@markovi.net>,
	linux-kbuild@vger.kernel.org
Cc: kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH][next] unicode: fix dereference of a potentially null pointer
Date: Fri, 26 Apr 2019 22:22:37 +0000	[thread overview]
Message-ID: <20190426222237.13209-1-colin.king@canonical.com> (raw)

From: Colin Ian King <colin.king@canonical.com>

The pointer 'tree' is deferenced when assigning pointer 'trie', however
trie is being null checked a few lines later, so it could potentially
be null. Fix the potential null pointer dereference by only dereferencing
it after it has been null checked.

Addresses-Coverity: ("Dereference before null check")
Fixes: b08fcacaaaf4 ("unicode: introduce UTF-8 character database")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
---
 scripts/mkutf8data.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/scripts/mkutf8data.c b/scripts/mkutf8data.c
index 12ce94b43be6..0563ba679bbb 100644
--- a/scripts/mkutf8data.c
+++ b/scripts/mkutf8data.c
@@ -2706,7 +2706,7 @@ static utf8leaf_t *utf8hangul(const char *str, unsigned char *hangul)
 static utf8leaf_t *utf8nlookup(struct tree *tree, unsigned char *hangul,
 			       const char *s, size_t len)
 {
-	utf8trie_t	*trie = utf8data + tree->index;
+	utf8trie_t	*trie;
 	int		offlen;
 	int		offset;
 	int		mask;
@@ -2716,6 +2716,7 @@ static utf8leaf_t *utf8nlookup(struct tree *tree, unsigned char *hangul,
 		return NULL;
 	if (len = 0)
 		return NULL;
+	trie = utf8data + tree->index;
 	node = 1;
 	while (node) {
 		offlen = (*trie & OFFLEN) >> OFFLEN_SHIFT;
-- 
2.20.1

             reply	other threads:[~2019-04-26 22:22 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-04-26 22:22 Colin King [this message]
2019-04-26 22:22 ` [PATCH][next] unicode: fix dereference of a potentially null pointer Colin King
2019-04-27  6:29 ` Masahiro Yamada
2019-04-27  6:29   ` Masahiro Yamada
2019-04-28 11:02   ` Gabriel Krisman Bertazi
2019-04-28 11:02     ` Gabriel Krisman Bertazi
2019-04-28 13:21     ` Theodore Ts'o
2019-04-28 13:21       ` Theodore Ts'o

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