Merge: srv6: stable backport for 10.2 phase 1

MR: https://gitlab.com/redhat/centos-stream/src/kernel/centos-stream-10/-/merge_requests/1450

JIRA: https://issues.redhat.com/browse/RHEL-115599

 * 7632fed seg6: Fix validation of nexthop addresses
 * 84967de ipv6: sr: validate HMAC algorithm ID in seg6_hmac_info_add
 * a458b29 ipv6: sr: Fix MAC comparison to be constant-time

Signed-off-by: CKI Backport Bot <cki-ci-bot+cki-gitlab-backport-bot@redhat.com>

---

<small>Created 2025-09-18 05:44 UTC by backporter - [KWF FAQ](https://red.ht/kernel_workflow_doc) - [Slack #team-kernel-workflow](https://redhat-internal.slack.com/archives/C04LRUPMJQ5) - [Source](https://gitlab.com/cki-project/kernel-workflow/-/blob/main/webhook/utils/backporter.py) - [Documentation](https://gitlab.com/cki-project/kernel-workflow/-/blob/main/docs/README.backporter.md) - [Report an issue](https://issues.redhat.com/secure/CreateIssueDetails!init.jspa?pid=12334433&issuetype=1&priority=4&summary=backporter+webhook+issue&components=kernel-workflow+/+backporter)</small>

Approved-by: Sabrina Dubroca <sdubroca@redhat.com>
Approved-by: Antoine Tenart <atenart@redhat.com>
Approved-by: CKI KWF Bot <cki-ci-bot+kwf-gitlab-com@redhat.com>

Merged-by: Scott Weaver <scweaver@redhat.com>

Author: swvrrh

net/ipv6/seg6_hmac.c

@@ -35,6 +35,7 @@
 #include <net/xfrm.h>
 
 #include <crypto/hash.h>
+#include <crypto/utils.h>
 #include <net/seg6.h>
 #include <net/genetlink.h>
 #include <net/seg6_hmac.h>
@@ -271,7 +272,7 @@ bool seg6_hmac_validate_skb(struct sk_buff *skb)
 	if (seg6_hmac_compute(hinfo, srh, &ipv6_hdr(skb)->saddr, hmac_output))
 		return false;
 
-	if (memcmp(hmac_output, tlv->hmac, SEG6_HMAC_FIELD_LEN) != 0)
+	if (crypto_memneq(hmac_output, tlv->hmac, SEG6_HMAC_FIELD_LEN))
 		return false;
 
 	return true;
@@ -295,6 +296,9 @@ int seg6_hmac_info_add(struct net *net, u32 key, struct seg6_hmac_info *hinfo)
 	struct seg6_pernet_data *sdata = seg6_pernet(net);
 	int err;
 
+	if (!__hmac_get_algo(hinfo->alg_id))
+		return -EINVAL;
+
 	err = rhashtable_lookup_insert_fast(&sdata->hmac_infos, &hinfo->node,
 					    rht_params);
 

net/ipv6/seg6_local.c

@@ -1644,10 +1644,8 @@ static const struct nla_policy seg6_local_policy[SEG6_LOCAL_MAX + 1] = {
 	[SEG6_LOCAL_SRH]	= { .type = NLA_BINARY },
 	[SEG6_LOCAL_TABLE]	= { .type = NLA_U32 },
 	[SEG6_LOCAL_VRFTABLE]	= { .type = NLA_U32 },
-	[SEG6_LOCAL_NH4]	= { .type = NLA_BINARY,
-				    .len = sizeof(struct in_addr) },
-	[SEG6_LOCAL_NH6]	= { .type = NLA_BINARY,
-				    .len = sizeof(struct in6_addr) },
+	[SEG6_LOCAL_NH4]	= NLA_POLICY_EXACT_LEN(sizeof(struct in_addr)),
+	[SEG6_LOCAL_NH6]	= NLA_POLICY_EXACT_LEN(sizeof(struct in6_addr)),
 	[SEG6_LOCAL_IIF]	= { .type = NLA_U32 },
 	[SEG6_LOCAL_OIF]	= { .type = NLA_U32 },
 	[SEG6_LOCAL_BPF]	= { .type = NLA_NESTED },