diff mbox series

[5.7,48/79] cfg80211: check vendor command doit pointer before use

Message ID 20200810151814.637692808@linuxfoundation.org
State New
Headers show
Series None | expand

Commit Message

Greg KH Aug. 10, 2020, 3:21 p.m. UTC 
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 mbox series

Patch

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 7ae6b90e0d264..970f05c4150ea 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -13190,13 +13190,13 @@  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]);