staging: rtl8723bs: fix OOB read in rtw_action_frame_parse()grafted

rtw_action_frame_parse() takes a frame_len parameter but never
actually checks it before indexing into the frame body:

	const u8 *frame_body = frame + sizeof(struct ieee80211_hdr_3addr);
	...
	c = frame_body[0];
	...
	a = frame_body[1];

frame_body already points 24 bytes (sizeof(struct
ieee80211_hdr_3addr)) into frame, so reading frame_body[0] and
frame_body[1] requires frame_len >= 26. A management action frame
shorter than that (e.g. exactly 24 bytes, the minimum a malicious
peer can send) causes a 1-2 byte out-of-bounds read.

This is reachable from rtw_cfg80211_monitor_if_xmit_entry() and
cfg80211_rtw_mgmt_tx() in ioctl_cfg80211.c, both of which pass
attacker/user-influenced frame buffers and lengths straight through.

Add the missing length check before frame_body is dereferenced.

Fixes: 554c0a3abf216 ("staging: Add rtl8723bs sdio wifi driver")
Cc: stable@vger.kernel.org
Signed-off-by: Muhammad Bilal <meatuni001@gmail.com>
Link: https://patch.msgid.link/20260728125456.32359-3-meatuni001@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 94 insertions, 0 deletions

diff --git a/net/ethtool/phc_vclocks.c b/net/ethtool/phc_vclocks.c
new file mode 100644
index 000000000..15146e38a
--- /dev/null
+++ b/net/ethtool/phc_vclocks.c
@@ -0,0 +1,94 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright 2021 NXP
+ */
+#include "common.h"
+#include "netlink.h"
+
+struct phc_vclocks_req_info {
+	struct ethnl_req_info		base;
+};
+
+struct phc_vclocks_reply_data {
+	struct ethnl_reply_data		base;
+	int				num;
+	int				*index;
+};
+
+#define PHC_VCLOCKS_REPDATA(__reply_base) \
+	container_of(__reply_base, struct phc_vclocks_reply_data, base)
+
+const struct nla_policy ethnl_phc_vclocks_get_policy[] = {
+	[ETHTOOL_A_PHC_VCLOCKS_HEADER] = NLA_POLICY_NESTED(ethnl_header_policy),
+};
+
+static int phc_vclocks_prepare_data(const struct ethnl_req_info *req_base,
+				    struct ethnl_reply_data *reply_base,
+				    const struct genl_info *info)
+{
+	struct phc_vclocks_reply_data *data = PHC_VCLOCKS_REPDATA(reply_base);
+	struct net_device *dev = reply_base->dev;
+	int ret;
+
+	ret = ethnl_ops_begin(dev);
+	if (ret < 0)
+		return ret;
+	data->num = ethtool_get_phc_vclocks(dev, &data->index);
+	ethnl_ops_complete(dev);
+
+	return ret;
+}
+
+static int phc_vclocks_reply_size(const struct ethnl_req_info *req_base,
+				  const struct ethnl_reply_data *reply_base)
+{
+	const struct phc_vclocks_reply_data *data =
+		PHC_VCLOCKS_REPDATA(reply_base);
+	int len = 0;
+
+	if (data->num > 0) {
+		len += nla_total_size(sizeof(u32));
+		len += nla_total_size(sizeof(s32) * data->num);
+	}
+
+	return len;
+}
+
+static int phc_vclocks_fill_reply(struct sk_buff *skb,
+				  const struct ethnl_req_info *req_base,
+				  const struct ethnl_reply_data *reply_base)
+{
+	const struct phc_vclocks_reply_data *data =
+		PHC_VCLOCKS_REPDATA(reply_base);
+
+	if (data->num <= 0)
+		return 0;
+
+	if (nla_put_u32(skb, ETHTOOL_A_PHC_VCLOCKS_NUM, data->num) ||
+	    nla_put(skb, ETHTOOL_A_PHC_VCLOCKS_INDEX,
+		    sizeof(s32) * data->num, data->index))
+		return -EMSGSIZE;
+
+	return 0;
+}
+
+static void phc_vclocks_cleanup_data(struct ethnl_reply_data *reply_base)
+{
+	const struct phc_vclocks_reply_data *data =
+		PHC_VCLOCKS_REPDATA(reply_base);
+
+	kfree(data->index);
+}
+
+const struct ethnl_request_ops ethnl_phc_vclocks_request_ops = {
+	.request_cmd		= ETHTOOL_MSG_PHC_VCLOCKS_GET,
+	.reply_cmd		= ETHTOOL_MSG_PHC_VCLOCKS_GET_REPLY,
+	.hdr_attr		= ETHTOOL_A_PHC_VCLOCKS_HEADER,
+	.req_info_size		= sizeof(struct phc_vclocks_req_info),
+	.reply_data_size	= sizeof(struct phc_vclocks_reply_data),
+
+	.prepare_data		= phc_vclocks_prepare_data,
+	.reply_size		= phc_vclocks_reply_size,
+	.fill_reply		= phc_vclocks_fill_reply,
+	.cleanup_data		= phc_vclocks_cleanup_data,
+};