Wed, Oct 09, 2019 at 06:44:32PM CEST, [email protected] wrote: >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 <[email protected]> >--- > 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);
Please also adjust genl_family_rcv_msg_attrs_free() call arg below in this function in the similar way. > 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 >
