diff options
| author | Daniel Borkmann | 2021-10-13 15:21:40 +0200 |
|---|---|---|
| committer | Jakub Kicinski | 2021-10-14 19:16:21 -0700 |
| commit | 30fc7efa38f21afa48b0be6bf2053e4c10ae2c78 (patch) | |
| tree | ecb461991215ba2658ce6d311ebb87da4a2a78aa /net/core/neighbour.c | |
| parent | c8e80c1169b2b3b91453f9ff3c34687c42233ef7 (diff) | |
net, neigh: Reject creating NUD_PERMANENT with NTF_MANAGED entries
The combination of NUD_PERMANENT + NTF_MANAGED is not supported and does
not make sense either given the former indicates a static/fixed neighbor
entry whereas the latter a dynamically resolved one. While it is possible
to transition from one over to the other, we should however reject such
creation attempts.
Fixes: 7482e3841d52 ("net, neigh: Add NTF_MANAGED flag for managed neighbor entries")
Suggested-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net/core/neighbour.c')
| -rw-r--r-- | net/core/neighbour.c | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/net/core/neighbour.c b/net/core/neighbour.c index 922b9ed0fe76..47931c8be04b 100644 --- a/net/core/neighbour.c +++ b/net/core/neighbour.c @@ -1999,15 +1999,20 @@ static int neigh_add(struct sk_buff *skb, struct nlmsghdr *nlh, neigh = neigh_lookup(tbl, dst, dev); if (neigh == NULL) { - bool exempt_from_gc; + bool ndm_permanent = ndm->ndm_state & NUD_PERMANENT; + bool exempt_from_gc = ndm_permanent || + ndm_flags & NTF_EXT_LEARNED; if (!(nlh->nlmsg_flags & NLM_F_CREATE)) { err = -ENOENT; goto out; } + if (ndm_permanent && (ndm_flags & NTF_MANAGED)) { + NL_SET_ERR_MSG(extack, "Invalid NTF_* flag for permanent entry"); + err = -EINVAL; + goto out; + } - exempt_from_gc = ndm->ndm_state & NUD_PERMANENT || - ndm_flags & NTF_EXT_LEARNED; neigh = ___neigh_create(tbl, dst, dev, ndm_flags & (NTF_EXT_LEARNED | NTF_MANAGED), |