[PATCH AUTOSEL 6.6 02/12] wifi: cfg80211: wext: add extra SIOCSIWSCAN data check

Sasha Levin
2024-07-01T00:13:47Z

From: Dmitry Antipov <dmantipov@yandex.ru>

[ Upstream commit 6ef09cdc5ba0f93826c09d810c141a8d103a80fc ]

In 'cfg80211_wext_siwscan()', add extra check whether number of
channels passed via 'ioctl(sock, SIOCSIWSCAN, ...)' doesn't exceed
IW_MAX_FREQUENCIES and reject invalid request with -EINVAL otherwise.

Reported-by: syzbot+253cd2d2491df77c93ac@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=253cd2d2491df77c93ac
Signed-off-by: Dmitry Antipov <dmantipov@yandex.ru>
Link: https://msgid.link/20240531032010.451295-1-dmantipov@yandex.ru
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/wireless/scan.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/net/wireless/scan.c b/net/wireless/scan.c
index c646094a5fc47..af81cf81f68ff 100644
--- a/net/wireless/scan.c
+++ b/net/wireless/scan.c
@@ -3163,10 +3163,14 @@ int cfg80211_wext_siwscan(struct net_device *dev,
wiphy = &rdev->wiphy;

/* Determine number of channels, needed to allocate creq */
- if (wreq && wreq->num_channels)
+ if (wreq && wreq->num_channels) {
+ /* Passed from userspace so should be checked */
+ if (unlikely(wreq->num_channels > IW_MAX_FREQUENCIES))
+ return -EINVAL;
n_channels = wreq->num_channels;
- else
+ } else {
n_channels = ieee80211_get_num_supported_channels(wiphy);
+ }

creq = kzalloc(sizeof(*creq) + sizeof(struct cfg80211_ssid) +
n_channels * sizeof(void *),
--
2.43.0