cfg80211: check vendor command doit pointer before use

[ Upstream commit 4052d3d2e8 ]

In the case where a vendor command does not implement doit, and has no
flags set, doit would not be validated and a NULL pointer dereference
would occur, for example when invoking the vendor command via iw.

I encountered this while developing new vendor commands.  Perhaps in
practice it is advisable to always implement doit along with dumpit,
but it seems reasonable to me to always check doit anyway, not just
when NEED_WDEV.

Signed-off-by: Julian Squires <julian@cipht.net>
Link: https://lore.kernel.org/r/20200706211353.2366470-1-julian@cipht.net
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Julian Squires 2020-07-06 17:13:53 -04:00 committed by Greg Kroah-Hartman
parent 83ea63708a
commit 7c8a863ba3
1 changed files with 3 additions and 3 deletions

View File

@ -12949,13 +12949,13 @@ static int nl80211_vendor_cmd(struct sk_buff *skb, struct genl_info *info)
if (!wdev_running(wdev))
return -ENETDOWN;
}
if (!vcmd->doit)
return -EOPNOTSUPP;
} else {
wdev = NULL;
}
if (!vcmd->doit)
return -EOPNOTSUPP;
if (info->attrs[NL80211_ATTR_VENDOR_DATA]) {
data = nla_data(info->attrs[NL80211_ATTR_VENDOR_DATA]);
len = nla_len(info->attrs[NL80211_ATTR_VENDOR_DATA]);