From: Ido Schimmel idosch@nvidia.com
commit 7632fedb266d93ed0ed9f487133e6c6314a9b2d1 upstream.
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 petrm@nvidia.com Signed-off-by: Ido Schimmel idosch@nvidia.com Reviewed-by: David Ahern dsahern@kernel.org Link: https://patch.msgid.link/20250604113252.371528-1-idosch@nvidia.com Signed-off-by: Jakub Kicinski kuba@kernel.org [ kovalev: bp to fix CVE-2025-38310 ] Signed-off-by: Vasiliy Kovalev kovalev@altlinux.org --- 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 de0b20cd09f0..26e7498206d8 100644 --- a/net/ipv6/seg6_local.c +++ b/net/ipv6/seg6_local.c @@ -648,10 +648,8 @@ static const struct nla_policy seg6_local_policy[SEG6_LOCAL_MAX + 1] = { [SEG6_LOCAL_ACTION] = { .type = NLA_U32 }, [SEG6_LOCAL_SRH] = { .type = NLA_BINARY }, [SEG6_LOCAL_TABLE] = { .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 },