From cef33a86bcb04ecf4dc10c56f6c42ee9d1c54bac 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 [ Upstream commit 7632fedb266d93ed0ed9f487133e6c6314a9b2d1 ] 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 Signed-off-by: Sasha Levin --- 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 33cb0381b5749..b7d9a68a265d7 100644 --- a/net/ipv6/seg6_local.c +++ b/net/ipv6/seg6_local.c @@ -1250,10 +1250,8 @@ 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 }, -- 2.47.3