[PATCH 1/2] SUNRPC: prevent integer overflow in XDR_QUADLEN()

[Dan Carpenter]

The "l + 3" addition can have integer overflow on 32 bit systems
when it is used in __xdr_inline_decode().  The overflowed value
would be zero and the check "nwords > xdr->nwords" would not work
as intended.

Fixes: ba8e452a4fe6 ("SUNRPC: Add a helper function xdr_inline_peek")
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
---
 include/linux/sunrpc/xdr.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/include/linux/sunrpc/xdr.h b/include/linux/sunrpc/xdr.h
index 2f8dc47f1eb0..585059f2afca 100644
--- a/include/linux/sunrpc/xdr.h
+++ b/include/linux/sunrpc/xdr.h
@@ -14,6 +14,7 @@
 #include <linux/uio.h>
 #include <asm/byteorder.h>
 #include <asm/unaligned.h>
+#include <linux/overflow.h>
 #include <linux/scatterlist.h>
 
 struct bio_vec;
@@ -29,7 +30,7 @@ struct rpc_rqst;
 /*
  * Buffer adjustment
  */
-#define XDR_QUADLEN(l)		(((l) + 3) >> 2)
+#define XDR_QUADLEN(l)		(size_add(l, 3) >> 2)
 
 /*
  * Generic opaque `network object.'
-- 
2.43.0