netdev - [PATCH net 2/5] ipv4: Check attribute length for RTA

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20211231003635.91219-3-dsahern@kernel.org>
Date:   Thu, 30 Dec 2021 17:36:32 -0700
From:   David Ahern <dsahern@...nel.org>
To:     netdev@...r.kernel.org
Cc:     idosch@...sch.org, David Ahern <dsahern@...nel.org>
Subject: [PATCH net 2/5] 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 <dsahern@...nel.org>
---
 net/ipv4/fib_semantics.c | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
index f1caa2c1c041..36bc429f1635 100644
--- a/net/ipv4/fib_semantics.c
+++ b/net/ipv4/fib_semantics.c
@@ -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
 		}
 
-- 
2.24.3 (Apple Git-128)