Title: [6568] trunk/arch/blackfin/include/asm/uaccess.h: Fix [#5202].
- Revision
- 6568
- Author
- rgetz
- Date
- 2009-06-03 19:32:59 -0500 (Wed, 03 Jun 2009)
Log Message
Fix [#5202].
Make sure we check the userspace pointer before the kernel acts on it.
Modified Paths
Diff
Modified: trunk/arch/blackfin/include/asm/uaccess.h (6567 => 6568)
--- trunk/arch/blackfin/include/asm/uaccess.h 2009-06-04 00:08:05 UTC (rev 6567)
+++ trunk/arch/blackfin/include/asm/uaccess.h 2009-06-04 00:32:59 UTC (rev 6568)
@@ -233,17 +233,32 @@
}
/*
- * Return the size of a string (including the ending 0)
+ * Get the size of a string in user space.
+ * src: The string to measure
+ * n: The maximum valid length
*
- * Return 0 on exception, a value greater than N if too long
+ * Get the size of a NUL-terminated string in user space.
+ *
+ * Returns the size of the string INCLUDING the terminating NUL.
+ * On exception, returns 0.
+ * If the string is too long, returns a value greater than n.
*/
-static inline long strnlen_user(const char *src, long n)
+static inline long __must_check strnlen_user(const char *src, long n)
{
- return (strlen(src) + 1);
+ if (!access_ok(VERIFY_READ, src, n))
+ return 0;
+ return strnlen(src, n) + 1;
}
-#define strlen_user(str) strnlen_user(str, 32767)
+/* We don't know the length, so only check the start of the string */
+static inline long __must_check strlen_user(const char *src)
+{
+ if (!access_ok(VERIFY_READ, src, 1))
+ return 0;
+ return strlen(src) + 1;
+}
+
/*
* Zero Userspace
*/
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