Messages in this thread Patch in this message | ![/](/images/icornerl.gif) | | From | Michal Kubecek <> | Subject | [PATCH net-next] genetlink: do not parse attributes for families with zero maxattr | Date | Wed, 9 Oct 2019 18:44:32 +0200 (CEST) |
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Commit c10e6cf85e7d ("net: genetlink: push attrbuf allocation and parsing to a separate function") moved attribute buffer allocation and attribute parsing from genl_family_rcv_msg_doit() into a separate function genl_family_rcv_msg_attrs_parse() which, unlike the previous code, calls __nlmsg_parse() even if family->maxattr is 0 (i.e. the family does its own parsing). The parser error is ignored and does not propagate out of genl_family_rcv_msg_attrs_parse() but an error message ("Unknown attribute type") is set in extack and if further processing generates no error or warning, it stays there and is interpreted as a warning by userspace.
Dumpit requests are not affected as genl_family_rcv_msg_dumpit() bypasses the call of genl_family_rcv_msg_doit() if family->maxattr is zero. Do the same also in genl_family_rcv_msg_doit().
Fixes: c10e6cf85e7d ("net: genetlink: push attrbuf allocation and parsing to a separate function") Signed-off-by: Michal Kubecek <mkubecek@suse.cz> --- net/netlink/genetlink.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/net/netlink/genetlink.c b/net/netlink/genetlink.c index ecc2bd3e73e4..c4bf8830eedf 100644 --- a/net/netlink/genetlink.c +++ b/net/netlink/genetlink.c @@ -639,21 +639,23 @@ static int genl_family_rcv_msg_doit(const struct genl_family *family, const struct genl_ops *ops, int hdrlen, struct net *net) { - struct nlattr **attrbuf; + struct nlattr **attrbuf = NULL; struct genl_info info; int err; if (!ops->doit) return -EOPNOTSUPP; + if (!family->maxattr) + goto no_attrs; attrbuf = genl_family_rcv_msg_attrs_parse(family, nlh, extack, ops, hdrlen, GENL_DONT_VALIDATE_STRICT, - family->maxattr && family->parallel_ops); if (IS_ERR(attrbuf)) return PTR_ERR(attrbuf); +no_attrs: info.snd_seq = nlh->nlmsg_seq; info.snd_portid = NETLINK_CB(skb).portid; info.nlhdr = nlh; -- 2.23.0
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