staging: vt6655: integer overflows in private_ioctl()

There are two potential integer overflows in private_ioctl() if userspace passes in a large sList.uItem / sNodeList.uItem. The subsequent call to kmalloc() would allocate a small buffer, leading to a memory corruption. Reported-by: Dan Rosenberg <[email protected]> Signed-off-by: Xi Wang <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
powerwareeasyman · Nov 30, 2011 · 2a58b19 · 2a58b19
1 parent fee6433
commit 2a58b19
Showing 1 changed file with 8 additions and 0 deletions.
diff --git a/drivers/staging/vt6655/ioctl.c b/drivers/staging/vt6655/ioctl.c
@@ -300,6 +300,10 @@ int private_ioctl(PSDevice pDevice, struct ifreq *rq)
 			result = -EFAULT;
 			break;
 		}
+		if (sList.uItem > (ULONG_MAX - sizeof(SBSSIDList)) / sizeof(SBSSIDItem)) {
+			result = -EINVAL;
+			break;
+		}
 		pList = (PSBSSIDList)kmalloc(sizeof(SBSSIDList) + (sList.uItem * sizeof(SBSSIDItem)), (int)GFP_ATOMIC);
 		if (pList == NULL) {
 			result = -ENOMEM;
@@ -571,6 +575,10 @@ int private_ioctl(PSDevice pDevice, struct ifreq *rq)
 			result = -EFAULT;
 			break;
 		}
+		if (sNodeList.uItem > (ULONG_MAX - sizeof(SNodeList)) / sizeof(SNodeItem)) {
+			result = -EINVAL;
+			break;
+		}
 		pNodeList = (PSNodeList)kmalloc(sizeof(SNodeList) + (sNodeList.uItem * sizeof(SNodeItem)), (int)GFP_ATOMIC);
 		if (pNodeList == NULL) {
 			result = -ENOMEM;