From: Johannes Berg <johannes.berg@intel.com>
Date: Wed, 15 Aug 2018 16:17:03 +0000 (+0200)
Subject: mac80211_hwsim: require at least one channel
X-Git-Tag: v4.14.75~88
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=381538ae75cfdcbda1ea7e3735ddb0cd369be67f;p=thirdparty%2Fkernel%2Fstable.git

mac80211_hwsim: require at least one channel

[ Upstream commit 484004339d4514fde425f6e8a9f6a6cc979bb0c3 ]

Syzbot continues to try to create mac80211_hwsim radios, and
manages to pass parameters that are later checked with WARN_ON
in cfg80211 - catch another one in hwsim directly.

Reported-by: syzbot+2a12f11c306afe871c1f@syzkaller.appspotmail.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/net/wireless/mac80211_hwsim.c b/drivers/net/wireless/mac80211_hwsim.c
index d686ba10fecc1..62fcf57e22999 100644
--- a/drivers/net/wireless/mac80211_hwsim.c
+++ b/drivers/net/wireless/mac80211_hwsim.c
@@ -3124,6 +3124,11 @@ static int hwsim_new_radio_nl(struct sk_buff *msg, struct genl_info *info)
 	if (info->attrs[HWSIM_ATTR_CHANNELS])
 		param.channels = nla_get_u32(info->attrs[HWSIM_ATTR_CHANNELS]);
 
+	if (param.channels < 1) {
+		GENL_SET_ERR_MSG(info, "must have at least one channel");
+		return -EINVAL;
+	}
+
 	if (param.channels > CFG80211_MAX_NUM_DIFFERENT_CHANNELS) {
 		GENL_SET_ERR_MSG(info, "too many channels specified");
 		return -EINVAL;