From: Julian Squires julian@cipht.net
[ Upstream commit 4052d3d2e8f47a15053320bbcbe365d15610437d ]
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 --- net/wireless/nl80211.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c index 0048f90944ddf..e107754e29a77 100644 --- a/net/wireless/nl80211.c +++ b/net/wireless/nl80211.c @@ -11317,13 +11317,13 @@ static int nl80211_vendor_cmd(struct sk_buff *skb, struct genl_info *info) if (!wdev->netdev && !wdev->p2p_started) 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]);