leandrof/linux
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Merge branch 'minor-managed-neighbor-follow-ups'

Browse Source 
Daniel Borkmann says:

====================
Minor managed neighbor follow-ups

Minor follow-up series to address prior feedback from David and Jakub.
Patch 1 adds a build time assertion to prevent overflows when shifting
in extended flags, patch 2 is a cleanup to use NLA_POLICY_MASK instead
of open-coding invalid flags rejection and patch 3 rejects creating new
neighbors with NUD_PERMANENT & NTF_MANAGED. For details, see individual
patches.
====================

Link: https://lore.kernel.org/r/20211013132140.11143-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Jakub Kicinski 2021-10-14 19:16:24 -07:00
commit c47fedba94
1 changed files with 12 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

20
net/core/neighbour.c
View File

@ -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 +1936,9 @@ 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)));
ndm_flags |= (ext << NTF_EXT_SHIFT);
}
if (ndm->ndm_ifindex) {
@ -2000,15 +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),