diff options
| author | Pablo Neira <pablo@netfilter.org> | 2013-07-29 12:30:04 +0200 |
|---|---|---|
| committer | Moyster <oysterized@gmail.com> | 2018-04-13 14:47:21 +0200 |
| commit | 9fb6012d26b2d4335a3a3d19ec73a8a1c5a09de6 (patch) | |
| tree | a3a30cefbef92ec1af1aa974f55a8273e090c525 | |
| parent | 552d7d58463e24a3eb4fefce58940891416492b7 (diff) | |
UPSTREAM: genetlink: fix usage of NLM_F_EXCL or NLM_F_REPLACE
Currently, it is not possible to use neither NLM_F_EXCL nor
NLM_F_REPLACE from genetlink. This is due to this checking in
genl_family_rcv_msg:
if (nlh->nlmsg_flags & NLM_F_DUMP)
NLM_F_DUMP is NLM_F_MATCH|NLM_F_ROOT. Thus, if NLM_F_EXCL or
NLM_F_REPLACE flag is set, genetlink believes that you're
requesting a dump and it calls the .dumpit callback.
The solution that I propose is to refine this checking to
make it stricter:
if ((nlh->nlmsg_flags & NLM_F_DUMP) == NLM_F_DUMP)
And given the combination NLM_F_REPLACE and NLM_F_EXCL does
not make sense to me, it removes the ambiguity.
There was a patch that tried to fix this some time ago (0ab03c2
netlink: test for all flags of the NLM_F_DUMP composite) but it
tried to resolve this ambiguity in *all* existing netlink subsystems,
not only genetlink. That patch was reverted since it broke iproute2,
which is using NLM_F_ROOT to request the dump of the routing cache.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit e1ee3673a83cc02b6b5e43c9e647d8dd5e1c4e26)
Change-Id: I1e7dfdfb1accfd22a171eb9a9a993e5b191dd27f
| -rw-r--r-- | net/netlink/genetlink.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/net/netlink/genetlink.c b/net/netlink/genetlink.c index ade434b8a..c7408dd8f 100644 --- a/net/netlink/genetlink.c +++ b/net/netlink/genetlink.c @@ -595,7 +595,7 @@ static int genl_family_rcv_msg(struct genl_family *family, !netlink_capable(skb, CAP_NET_ADMIN)) return -EPERM; - if (nlh->nlmsg_flags & NLM_F_DUMP) { + if ((nlh->nlmsg_flags & NLM_F_DUMP) == NLM_F_DUMP) { int rc; if (ops->dumpit == NULL) |