commit 8f0750f19789cf352d7e24a6cc50f2ab1b4f1372
author Dan Carpenter <dan.carpenter@oracle.com> Sat Mar 24 10:52:50 2012 +0300
committer H. Peter Anvin <hpa@zytor.com> Wed Mar 28 09:39:35 2012 -0700
tree 45be3ac15f47a9330604d1b21378e8dfa90251b3
parent 136d249ef7dbf0fefa292082cc40be1ea864cbd6

x86, tls: Off by one limit check

These are used as offsets into an array of GDT_ENTRY_TLS_ENTRIES members
so GDT_ENTRY_TLS_ENTRIES is one past the end of the array.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: http://lkml.kernel.org/r/20120324075250.GA28258@elgon.mountain
Cc: <stable@vger.kernel.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

arch/x86/kernel/tls.c

diff --git a/arch/x86/kernel/tls.c b/arch/x86/kernel/tls.c
index 6bb7b85..bcfec2d 100644
--- a/arch/x86/kernel/tls.c
+++ b/arch/x86/kernel/tls.c
@@ -163,7 +163,7 @@
 {
 	const struct desc_struct *tls;
 
-	if (pos > GDT_ENTRY_TLS_ENTRIES * sizeof(struct user_desc) ||
+	if (pos >= GDT_ENTRY_TLS_ENTRIES * sizeof(struct user_desc) ||
 	    (pos % sizeof(struct user_desc)) != 0 ||
 	    (count % sizeof(struct user_desc)) != 0)
 		return -EINVAL;
@@ -198,7 +198,7 @@
 	struct user_desc infobuf[GDT_ENTRY_TLS_ENTRIES];
 	const struct user_desc *info;
 
-	if (pos > GDT_ENTRY_TLS_ENTRIES * sizeof(struct user_desc) ||
+	if (pos >= GDT_ENTRY_TLS_ENTRIES * sizeof(struct user_desc) ||
 	    (pos % sizeof(struct user_desc)) != 0 ||
 	    (count % sizeof(struct user_desc)) != 0)
 		return -EINVAL;