Instead of open-coding a check for invalid bits in NTF_EXT_MASK, we can just use the NLA_POLICY_MASK() helper instead, and simplify NDA_FLAGS_EXT sanity check this way. Suggested-by: Jakub Kicinski <kuba@xxxxxxxxxx> Signed-off-by: Daniel Borkmann <daniel@xxxxxxxxxxxxx> --- net/core/neighbour.c | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-) diff --git a/net/core/neighbour.c b/net/core/neighbour.c index 4fc601f9cd06..922b9ed0fe76 100644 --- a/net/core/neighbour.c +++ b/net/core/neighbour.c @@ -1834,7 +1834,7 @@ const struct nla_policy nda_policy[NDA_MAX+1] = { [NDA_MASTER] = { .type = NLA_U32 }, [NDA_PROTOCOL] = { .type = NLA_U8 }, [NDA_NH_ID] = { .type = NLA_U32 }, - [NDA_FLAGS_EXT] = { .type = NLA_U32 }, + [NDA_FLAGS_EXT] = NLA_POLICY_MASK(NLA_U32, NTF_EXT_MASK), [NDA_FDB_EXT_ATTRS] = { .type = NLA_NESTED }, }; @@ -1936,10 +1936,6 @@ static int neigh_add(struct sk_buff *skb, struct nlmsghdr *nlh, if (tb[NDA_FLAGS_EXT]) { u32 ext = nla_get_u32(tb[NDA_FLAGS_EXT]); - if (ext & ~NTF_EXT_MASK) { - NL_SET_ERR_MSG(extack, "Invalid extended flags"); - goto out; - } BUILD_BUG_ON(sizeof(neigh->flags) * BITS_PER_BYTE < (sizeof(ndm->ndm_flags) * BITS_PER_BYTE + hweight32(NTF_EXT_MASK))); -- 2.27.0