From 7c8a863ba3cbbfdd5358c63c51f07681973babde Mon Sep 17 00:00:00 2001 From: Julian Squires Date: Mon, 6 Jul 2020 17:13:53 -0400 Subject: [PATCH] cfg80211: check vendor command doit pointer before use [ 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 Link: https://lore.kernel.org/r/20200706211353.2366470-1-julian@cipht.net Signed-off-by: Johannes Berg Signed-off-by: Sasha Levin --- 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 a34bbca80f49..ec559dbad56e 100644 --- a/net/wireless/nl80211.c +++ b/net/wireless/nl80211.c @@ -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]);