Commit 4052d3d2 authored Jul 06, 2020 by Julian Squires Committed by Johannes Berg Jul 30, 2020

cfg80211: check vendor command doit pointer before use



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>

parent 5e43540c

net/wireless/nl80211.c

+3 −3

Original line number	Diff line number	Diff line
		@@ -13266,13 +13266,13 @@ 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]);

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