/fs/proc/: 'larger than buffer size' memory accesses by clear_user()

From: Adam B. Jerome <[email protected]>

This patch addresses potential 'larger than buffer size' memory accesses by clear_user(). Without this patch, this call to clear_user() can attempt to clear too many (tsz) bytes resulting in a wrong (-EFAULT) return code by read_kcore().

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I do not subscribe to the list. Please CC posted answers/comments CC me <[email protected]>. Thanks; -adam

diff -urpN linux-2.6-git/fs/proc/kcore.c linux-2.6-cur/fs/proc/kcore.c
@@ -384,7 +384,7 @@ read_kcore(struct file *file, char __use
 				 */
 				if (n) { 
 					if (clear_user(buffer + tsz - n,
-								tsz - n))
+								n))
 						return -EFAULT;
 				}
 			} else {