[PATCH AUTOSEL 6.9 02/20] wifi: cfg80211: wext: add extra SIOCSIWSCAN data check

[PATCH AUTOSEL 6.9 02/20] wifi: cfg80211: wext: add extra SIOCSIWSCAN data check

[Sasha Levin]

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 ecea8c08e2701..43eb77b4d2a67 100644
--- a/net/wireless/scan.c
+++ b/net/wireless/scan.c
@@ -3396,10 +3396,14 @@ 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

[PATCH AUTOSEL 6.9 07/20] wifi: mac80211: Avoid address calculations via out of bounds array indexing

[Sasha Levin]

From: Kenton Groombridge <concord@gentoo.org>

[ Upstream commit 2663d0462eb32ae7c9b035300ab6b1523886c718 ]

req->n_channels must be set before req->channels[] can be used.

This patch fixes one of the issues encountered in [1].

[   83.964255] UBSAN: array-index-out-of-bounds in net/mac80211/scan.c:364:4
[   83.964258] index 0 is out of range for type 'struct ieee80211_channel *[]'
[...]
[   83.964264] Call Trace:
[   83.964267]  <TASK>
[   83.964269]  dump_stack_lvl+0x3f/0xc0
[   83.964274]  __ubsan_handle_out_of_bounds+0xec/0x110
[   83.964278]  ieee80211_prep_hw_scan+0x2db/0x4b0
[   83.964281]  __ieee80211_start_scan+0x601/0x990
[   83.964291]  nl80211_trigger_scan+0x874/0x980
[   83.964295]  genl_family_rcv_msg_doit+0xe8/0x160
[   83.964298]  genl_rcv_msg+0x240/0x270
[...]

[1] https://bugzilla.kernel.org/show_bug.cgi?id=218810

Co-authored-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Kees Cook <kees@kernel.org>
Signed-off-by: Kenton Groombridge <concord@gentoo.org>
Link: https://msgid.link/20240605152218.236061-1-concord@gentoo.org
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/mac80211/scan.c | 17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/net/mac80211/scan.c b/net/mac80211/scan.c
index 3da1c5c450358..a142d18fb6824 100644
--- a/net/mac80211/scan.c
+++ b/net/mac80211/scan.c
@@ -358,7 +358,8 @@ static bool ieee80211_prep_hw_scan(struct ieee80211_sub_if_data *sdata)
 	struct cfg80211_scan_request *req;
 	struct cfg80211_chan_def chandef;
 	u8 bands_used = 0;
-	int i, ielen, n_chans;
+	int i, ielen;
+	u32 *n_chans;
 	u32 flags = 0;
 
 	req = rcu_dereference_protected(local->scan_req,
@@ -368,34 +369,34 @@ static bool ieee80211_prep_hw_scan(struct ieee80211_sub_if_data *sdata)
 		return false;
 
 	if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
+		local->hw_scan_req->req.n_channels = req->n_channels;
+
 		for (i = 0; i < req->n_channels; i++) {
 			local->hw_scan_req->req.channels[i] = req->channels[i];
 			bands_used |= BIT(req->channels[i]->band);
 		}
-
-		n_chans = req->n_channels;
 	} else {
 		do {
 			if (local->hw_scan_band == NUM_NL80211_BANDS)
 				return false;
 
-			n_chans = 0;
+			n_chans = &local->hw_scan_req->req.n_channels;
+			*n_chans = 0;
 
 			for (i = 0; i < req->n_channels; i++) {
 				if (req->channels[i]->band !=
 				    local->hw_scan_band)
 					continue;
-				local->hw_scan_req->req.channels[n_chans] =
+				local->hw_scan_req->req.channels[(*n_chans)++] =
 							req->channels[i];
-				n_chans++;
+
 				bands_used |= BIT(req->channels[i]->band);
 			}
 
 			local->hw_scan_band++;
-		} while (!n_chans);
+		} while (!*n_chans);
 	}
 
-	local->hw_scan_req->req.n_channels = n_chans;
 	ieee80211_prepare_scan_chandef(&chandef);
 
 	if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
-- 
2.43.0