From: Rasmus Villemoes <rasmus.villemoes@prevas.dk>
Date: Fri, 14 Oct 2022 17:43:37 +0000 (+0200)
Subject: net: improve check for no IP options
X-Git-Url: http://git.dujemihanovic.xyz/html/index.html?a=commitdiff_plain;h=b0fcc48cb37057ccbe29481d3297f7b9243a4b92;p=u-boot.git

net: improve check for no IP options

There's no reason we should accept an IP packet with a malformed IHL
field. So ensure that it is exactly 5, not just <= 5.

Signed-off-by: Rasmus Villemoes <rasmus.villemoes@prevas.dk>
Reviewed-by: Ramon Fried <rfried.dev@gmail.com>
---

diff --git a/net/net.c b/net/net.c
index b27b021d07..be4374ffc4 100644
--- a/net/net.c
+++ b/net/net.c
@@ -1226,7 +1226,7 @@ void net_process_received_packet(uchar *in_packet, int len)
 		if ((ip->ip_hl_v & 0xf0) != 0x40)
 			return;
 		/* Can't deal with IP options (headers != 20 bytes) */
-		if ((ip->ip_hl_v & 0x0f) > 0x05)
+		if ((ip->ip_hl_v & 0x0f) != 0x05)
 			return;
 		/* Check the Checksum of the header */
 		if (!ip_checksum_ok((uchar *)ip, IP_HDR_SIZE)) {