[PATCH] cxgb4: prevent potential integer overflow on 32bit

[Dan Carpenter]

The "gl->tot_len" variable is controlled by the user.  It comes from
process_responses().  On 32bit systems, the "gl->tot_len +
sizeof(struct cpl_pass_accept_req) + sizeof(struct rss_header)" addition
could have an integer wrapping bug.  Use size_add() to prevent this.

Fixes: a08943947873 ("crypto: chtls - Register chtls with net tls")
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
---
This is from static analysis.  I've spent some time reviewing this code
but I might be wrong.

 drivers/infiniband/hw/cxgb4/device.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/infiniband/hw/cxgb4/device.c b/drivers/infiniband/hw/cxgb4/device.c
index 80970a1738f8..034b85c42255 100644
--- a/drivers/infiniband/hw/cxgb4/device.c
+++ b/drivers/infiniband/hw/cxgb4/device.c
@@ -1114,8 +1114,10 @@ static inline struct sk_buff *copy_gl_to_skb_pkt(const struct pkt_gl *gl,
 	 * The math here assumes sizeof cpl_pass_accept_req >= sizeof
 	 * cpl_rx_pkt.
 	 */
-	skb = alloc_skb(gl->tot_len + sizeof(struct cpl_pass_accept_req) +
-			sizeof(struct rss_header) - pktshift, GFP_ATOMIC);
+	skb = alloc_skb(size_add(gl->tot_len,
+				 sizeof(struct cpl_pass_accept_req) +
+				 sizeof(struct rss_header)) - pktshift,
+			GFP_ATOMIC);
 	if (unlikely(!skb))
 		return NULL;
 
-- 
2.45.2