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FAILED: patch "[PATCH] ipv4: Check attribute length for RTA_FLOW in multipath route" failed to apply to 4.14-stable tree

PATCH [email protected] 1 participant 1 message Jan 7, 2022

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Networking Stable branch IPv4/IPv6
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The patch below does not apply to the 4.14-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 664b9c4b7392ce723b013201843264bf95481ce5 Mon Sep 17 00:00:00 2001
From: David Ahern <[email protected]>
Date: Thu, 30 Dec 2021 17:36:32 -0700
Subject: [PATCH] ipv4: Check attribute length for RTA_FLOW in multipath route

Make sure RTA_FLOW is at least 4B before using.

Fixes 4e902c57417c ("[IPv4]: FIB configuration using struct fib_config")
Signed-off-by David Ahern <[email protected]>
Signed-off-by David S. Miller <[email protected]>
net/ipv4/fib_semantics.c +14 -3
index f1caa2c1c041..36bc429f1635 100644
@@ -731,8 +731,13 @@ static int fib_get_nhs(struct fib_info *fi, struct rtnexthop *rtnh,
 			}
 
 			nla = nla_find(attrs, attrlen, RTA_FLOW);
-			if (nla)
+			if (nla) {
+				if (nla_len(nla) < sizeof(u32)) {
+					NL_SET_ERR_MSG(extack, "Invalid RTA_FLOW");
+					return -EINVAL;
+				}
 				fib_cfg.fc_flow = nla_get_u32(nla);
+			}
 
 			fib_cfg.fc_encap = nla_find(attrs, attrlen, RTA_ENCAP);
 			nla = nla_find(attrs, attrlen, RTA_ENCAP_TYPE);

@@ -963,8 +968,14 @@ int fib_nh_match(struct net *net, struct fib_config *cfg, struct fib_info *fi,
 
 #ifdef CONFIG_IP_ROUTE_CLASSID
 			nla = nla_find(attrs, attrlen, RTA_FLOW);
-			if (nla && nla_get_u32(nla) != nh->nh_tclassid)
-				return 1;
+			if (nla) {
+				if (nla_len(nla) < sizeof(u32)) {
+					NL_SET_ERR_MSG(extack, "Invalid RTA_FLOW");
+					return -EINVAL;
+				}
+				if (nla_get_u32(nla) != nh->nh_tclassid)
+					return 1;
+			}
 #endif
 		}