From 7632fedb266d93ed0ed9f487133e6c6314a9b2d1 Mon Sep 17 00:00:00 2001 From: Ido Schimmel Date: Wed, 4 Jun 2025 14:32:52 +0300 Subject: [PATCH] seg6: Fix validation of nexthop addresses The kernel currently validates that the length of the provided nexthop address does not exceed the specified length. This can lead to the kernel reading uninitialized memory if user space provided a shorter length than the specified one. Fix by validating that the provided length exactly matches the specified one. Fixes: d1df6fd8a1d2 ("ipv6: sr: define core operations for seg6local lightweight tunnel") Reviewed-by: Petr Machata Signed-off-by: Ido Schimmel Reviewed-by: David Ahern Link: https://patch.msgid.link/20250604113252.371528-1-idosch@nvidia.com Signed-off-by: Jakub Kicinski --- net/ipv6/seg6_local.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/net/ipv6/seg6_local.c b/net/ipv6/seg6_local.c index ac1dbd492c22..a11a02b4ba95 100644 --- a/net/ipv6/seg6_local.c +++ b/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 }, -- 2.25.1