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, 362 insertions, 0 deletions

diff --git a/net/ethtool/linkmodes.c b/net/ethtool/linkmodes.c
new file mode 100644
index 000000000..a6d32f0d9
--- /dev/null
+++ b/net/ethtool/linkmodes.c
@@ -0,0 +1,362 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include "bitset.h"
+#include "common.h"
+#include "netlink.h"
+
+/* LINKMODES_GET */
+
+struct linkmodes_req_info {
+	struct ethnl_req_info		base;
+};
+
+struct linkmodes_reply_data {
+	struct ethnl_reply_data		base;
+	struct ethtool_link_ksettings	ksettings;
+	struct ethtool_link_settings	*lsettings;
+	bool				peer_empty;
+};
+
+#define LINKMODES_REPDATA(__reply_base) \
+	container_of(__reply_base, struct linkmodes_reply_data, base)
+
+const struct nla_policy ethnl_linkmodes_get_policy[] = {
+	[ETHTOOL_A_LINKMODES_HEADER]		=
+		NLA_POLICY_NESTED(ethnl_header_policy),
+};
+
+static int linkmodes_prepare_data(const struct ethnl_req_info *req_base,
+				  struct ethnl_reply_data *reply_base,
+				  const struct genl_info *info)
+{
+	struct linkmodes_reply_data *data = LINKMODES_REPDATA(reply_base);
+	struct net_device *dev = reply_base->dev;
+	int ret;
+
+	data->lsettings = &data->ksettings.base;
+
+	ret = ethnl_ops_begin(dev);
+	if (ret < 0)
+		return ret;
+
+	ret = netif_get_link_ksettings(dev, &data->ksettings);
+	if (ret < 0) {
+		GENL_SET_ERR_MSG(info, "failed to retrieve link settings");
+		goto out;
+	}
+
+	if (!dev->ethtool_ops->cap_link_lanes_supported)
+		data->ksettings.lanes = 0;
+
+	data->peer_empty =
+		bitmap_empty(data->ksettings.link_modes.lp_advertising,
+			     __ETHTOOL_LINK_MODE_MASK_NBITS);
+
+out:
+	ethnl_ops_complete(dev);
+	return ret;
+}
+
+static int linkmodes_reply_size(const struct ethnl_req_info *req_base,
+				const struct ethnl_reply_data *reply_base)
+{
+	const struct linkmodes_reply_data *data = LINKMODES_REPDATA(reply_base);
+	const struct ethtool_link_ksettings *ksettings = &data->ksettings;
+	const struct ethtool_link_settings *lsettings = &ksettings->base;
+	bool compact = req_base->flags & ETHTOOL_FLAG_COMPACT_BITSETS;
+	int len, ret;
+
+	len = nla_total_size(sizeof(u8)) /* LINKMODES_AUTONEG */
+		+ nla_total_size(sizeof(u32)) /* LINKMODES_SPEED */
+		+ nla_total_size(sizeof(u32)) /* LINKMODES_LANES */
+		+ nla_total_size(sizeof(u8)) /* LINKMODES_DUPLEX */
+		+ nla_total_size(sizeof(u8)) /* LINKMODES_RATE_MATCHING */
+		+ 0;
+	ret = ethnl_bitset_size(ksettings->link_modes.advertising,
+				ksettings->link_modes.supported,
+				__ETHTOOL_LINK_MODE_MASK_NBITS,
+				link_mode_names, compact);
+	if (ret < 0)
+		return ret;
+	len += ret;
+	if (!data->peer_empty) {
+		ret = ethnl_bitset_size(ksettings->link_modes.lp_advertising,
+					NULL, __ETHTOOL_LINK_MODE_MASK_NBITS,
+					link_mode_names, compact);
+		if (ret < 0)
+			return ret;
+		len += ret;
+	}
+
+	if (lsettings->master_slave_cfg != MASTER_SLAVE_CFG_UNSUPPORTED)
+		len += nla_total_size(sizeof(u8));
+
+	if (lsettings->master_slave_state != MASTER_SLAVE_STATE_UNSUPPORTED)
+		len += nla_total_size(sizeof(u8));
+
+	return len;
+}
+
+static int linkmodes_fill_reply(struct sk_buff *skb,
+				const struct ethnl_req_info *req_base,
+				const struct ethnl_reply_data *reply_base)
+{
+	const struct linkmodes_reply_data *data = LINKMODES_REPDATA(reply_base);
+	const struct ethtool_link_ksettings *ksettings = &data->ksettings;
+	const struct ethtool_link_settings *lsettings = &ksettings->base;
+	bool compact = req_base->flags & ETHTOOL_FLAG_COMPACT_BITSETS;
+	int ret;
+
+	if (nla_put_u8(skb, ETHTOOL_A_LINKMODES_AUTONEG, lsettings->autoneg))
+		return -EMSGSIZE;
+
+	ret = ethnl_put_bitset(skb, ETHTOOL_A_LINKMODES_OURS,
+			       ksettings->link_modes.advertising,
+			       ksettings->link_modes.supported,
+			       __ETHTOOL_LINK_MODE_MASK_NBITS, link_mode_names,
+			       compact);
+	if (ret < 0)
+		return -EMSGSIZE;
+	if (!data->peer_empty) {
+		ret = ethnl_put_bitset(skb, ETHTOOL_A_LINKMODES_PEER,
+				       ksettings->link_modes.lp_advertising,
+				       NULL, __ETHTOOL_LINK_MODE_MASK_NBITS,
+				       link_mode_names, compact);
+		if (ret < 0)
+			return -EMSGSIZE;
+	}
+
+	if (nla_put_u32(skb, ETHTOOL_A_LINKMODES_SPEED, lsettings->speed) ||
+	    nla_put_u8(skb, ETHTOOL_A_LINKMODES_DUPLEX, lsettings->duplex))
+		return -EMSGSIZE;
+
+	if (ksettings->lanes &&
+	    nla_put_u32(skb, ETHTOOL_A_LINKMODES_LANES, ksettings->lanes))
+		return -EMSGSIZE;
+
+	if (lsettings->master_slave_cfg != MASTER_SLAVE_CFG_UNSUPPORTED &&
+	    nla_put_u8(skb, ETHTOOL_A_LINKMODES_MASTER_SLAVE_CFG,
+		       lsettings->master_slave_cfg))
+		return -EMSGSIZE;
+
+	if (lsettings->master_slave_state != MASTER_SLAVE_STATE_UNSUPPORTED &&
+	    nla_put_u8(skb, ETHTOOL_A_LINKMODES_MASTER_SLAVE_STATE,
+		       lsettings->master_slave_state))
+		return -EMSGSIZE;
+
+	if (nla_put_u8(skb, ETHTOOL_A_LINKMODES_RATE_MATCHING,
+		       lsettings->rate_matching))
+		return -EMSGSIZE;
+
+	return 0;
+}
+
+/* LINKMODES_SET */
+
+const struct nla_policy ethnl_linkmodes_set_policy[] = {
+	[ETHTOOL_A_LINKMODES_HEADER]		=
+		NLA_POLICY_NESTED(ethnl_header_policy),
+	[ETHTOOL_A_LINKMODES_AUTONEG]		= { .type = NLA_U8 },
+	[ETHTOOL_A_LINKMODES_OURS]		= { .type = NLA_NESTED },
+	[ETHTOOL_A_LINKMODES_SPEED]		= { .type = NLA_U32 },
+	[ETHTOOL_A_LINKMODES_DUPLEX]		= { .type = NLA_U8 },
+	[ETHTOOL_A_LINKMODES_MASTER_SLAVE_CFG]	= { .type = NLA_U8 },
+	[ETHTOOL_A_LINKMODES_LANES]		= NLA_POLICY_RANGE(NLA_U32, 1, 8),
+};
+
+/* Set advertised link modes to all supported modes matching requested speed,
+ * lanes and duplex values. Called when autonegotiation is on, speed, lanes or
+ * duplex is requested but no link mode change. This is done in userspace with
+ * ioctl() interface, move it into kernel for netlink.
+ * Returns true if advertised modes bitmap was modified.
+ */
+static bool ethnl_auto_linkmodes(struct ethtool_link_ksettings *ksettings,
+				 bool req_speed, bool req_lanes, bool req_duplex)
+{
+	unsigned long *advertising = ksettings->link_modes.advertising;
+	unsigned long *supported = ksettings->link_modes.supported;
+	DECLARE_BITMAP(old_adv, __ETHTOOL_LINK_MODE_MASK_NBITS);
+	unsigned int i;
+
+	bitmap_copy(old_adv, advertising, __ETHTOOL_LINK_MODE_MASK_NBITS);
+
+	for (i = 0; i < __ETHTOOL_LINK_MODE_MASK_NBITS; i++) {
+		const struct link_mode_info *info = &link_mode_params[i];
+
+		if (info->speed == SPEED_UNKNOWN)
+			continue;
+		if (test_bit(i, supported) &&
+		    (!req_speed || info->speed == ksettings->base.speed) &&
+		    (!req_lanes || info->lanes == ksettings->lanes) &&
+		    (!req_duplex || info->duplex == ksettings->base.duplex))
+			set_bit(i, advertising);
+		else
+			clear_bit(i, advertising);
+	}
+
+	return !bitmap_equal(old_adv, advertising,
+			     __ETHTOOL_LINK_MODE_MASK_NBITS);
+}
+
+static bool ethnl_validate_master_slave_cfg(u8 cfg)
+{
+	switch (cfg) {
+	case MASTER_SLAVE_CFG_MASTER_PREFERRED:
+	case MASTER_SLAVE_CFG_SLAVE_PREFERRED:
+	case MASTER_SLAVE_CFG_MASTER_FORCE:
+	case MASTER_SLAVE_CFG_SLAVE_FORCE:
+		return true;
+	}
+
+	return false;
+}
+
+static int ethnl_check_linkmodes(struct genl_info *info, struct nlattr **tb)
+{
+	const struct nlattr *master_slave_cfg, *lanes_cfg;
+
+	master_slave_cfg = tb[ETHTOOL_A_LINKMODES_MASTER_SLAVE_CFG];
+	if (master_slave_cfg &&
+	    !ethnl_validate_master_slave_cfg(nla_get_u8(master_slave_cfg))) {
+		NL_SET_ERR_MSG_ATTR(info->extack, master_slave_cfg,
+				    "master/slave value is invalid");
+		return -EOPNOTSUPP;
+	}
+
+	lanes_cfg = tb[ETHTOOL_A_LINKMODES_LANES];
+	if (lanes_cfg && !is_power_of_2(nla_get_u32(lanes_cfg))) {
+		NL_SET_ERR_MSG_ATTR(info->extack, lanes_cfg,
+				    "lanes value is invalid");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int ethnl_update_linkmodes(struct genl_info *info, struct nlattr **tb,
+				  struct ethtool_link_ksettings *ksettings,
+				  bool *mod, const struct net_device *dev)
+{
+	struct ethtool_link_settings *lsettings = &ksettings->base;
+	bool req_speed, req_lanes, req_duplex;
+	const struct nlattr *master_slave_cfg, *lanes_cfg;
+	int ret;
+
+	master_slave_cfg = tb[ETHTOOL_A_LINKMODES_MASTER_SLAVE_CFG];
+	if (master_slave_cfg) {
+		if (lsettings->master_slave_cfg == MASTER_SLAVE_CFG_UNSUPPORTED) {
+			NL_SET_ERR_MSG_ATTR(info->extack, master_slave_cfg,
+					    "master/slave configuration not supported by device");
+			return -EOPNOTSUPP;
+		}
+	}
+
+	*mod = false;
+	req_speed = tb[ETHTOOL_A_LINKMODES_SPEED];
+	req_lanes = tb[ETHTOOL_A_LINKMODES_LANES];
+	req_duplex = tb[ETHTOOL_A_LINKMODES_DUPLEX];
+
+	ethnl_update_u8(&lsettings->autoneg, tb[ETHTOOL_A_LINKMODES_AUTONEG],
+			mod);
+
+	lanes_cfg = tb[ETHTOOL_A_LINKMODES_LANES];
+	if (lanes_cfg) {
+		/* If autoneg is off and lanes parameter is not supported by the
+		 * driver, return an error.
+		 */
+		if (!lsettings->autoneg &&
+		    !dev->ethtool_ops->cap_link_lanes_supported) {
+			NL_SET_ERR_MSG_ATTR(info->extack, lanes_cfg,
+					    "lanes configuration not supported by device");
+			return -EOPNOTSUPP;
+		}
+	} else if (!lsettings->autoneg && ksettings->lanes) {
+		/* If autoneg is off and lanes parameter is not passed from user but
+		 * it was defined previously then set the lanes parameter to 0.
+		 */
+		ksettings->lanes = 0;
+		*mod = true;
+	}
+
+	ret = ethnl_update_bitset(ksettings->link_modes.advertising,
+				  __ETHTOOL_LINK_MODE_MASK_NBITS,
+				  tb[ETHTOOL_A_LINKMODES_OURS], link_mode_names,
+				  info->extack, mod);
+	if (ret < 0)
+		return ret;
+	ethnl_update_u32(&lsettings->speed, tb[ETHTOOL_A_LINKMODES_SPEED],
+			 mod);
+	ethnl_update_u32(&ksettings->lanes, lanes_cfg, mod);
+	ethnl_update_u8(&lsettings->duplex, tb[ETHTOOL_A_LINKMODES_DUPLEX],
+			mod);
+	ethnl_update_u8(&lsettings->master_slave_cfg, master_slave_cfg, mod);
+
+	if (!tb[ETHTOOL_A_LINKMODES_OURS] && lsettings->autoneg &&
+	    (req_speed || req_lanes || req_duplex) &&
+	    ethnl_auto_linkmodes(ksettings, req_speed, req_lanes, req_duplex))
+		*mod = true;
+
+	return 0;
+}
+
+static int
+ethnl_set_linkmodes_validate(struct ethnl_req_info *req_info,
+			     struct genl_info *info)
+{
+	const struct ethtool_ops *ops = req_info->dev->ethtool_ops;
+	int ret;
+
+	ret = ethnl_check_linkmodes(info, info->attrs);
+	if (ret < 0)
+		return ret;
+
+	if (!ops->get_link_ksettings || !ops->set_link_ksettings)
+		return -EOPNOTSUPP;
+	return 1;
+}
+
+static int
+ethnl_set_linkmodes(struct ethnl_req_info *req_info, struct genl_info *info)
+{
+	struct ethtool_link_ksettings ksettings = {};
+	struct net_device *dev = req_info->dev;
+	struct nlattr **tb = info->attrs;
+	bool mod = false;
+	int ret;
+
+	ret = netif_get_link_ksettings(dev, &ksettings);
+	if (ret < 0) {
+		GENL_SET_ERR_MSG(info, "failed to retrieve link settings");
+		return ret;
+	}
+
+	ret = ethnl_update_linkmodes(info, tb, &ksettings, &mod, dev);
+	if (ret < 0)
+		return ret;
+	if (!mod)
+		return 0;
+
+	ret = dev->ethtool_ops->set_link_ksettings(dev, &ksettings);
+	if (ret < 0) {
+		GENL_SET_ERR_MSG(info, "link settings update failed");
+		return ret;
+	}
+
+	return 1;
+}
+
+const struct ethnl_request_ops ethnl_linkmodes_request_ops = {
+	.request_cmd		= ETHTOOL_MSG_LINKMODES_GET,
+	.reply_cmd		= ETHTOOL_MSG_LINKMODES_GET_REPLY,
+	.hdr_attr		= ETHTOOL_A_LINKMODES_HEADER,
+	.req_info_size		= sizeof(struct linkmodes_req_info),
+	.reply_data_size	= sizeof(struct linkmodes_reply_data),
+
+	.prepare_data		= linkmodes_prepare_data,
+	.reply_size		= linkmodes_reply_size,
+	.fill_reply		= linkmodes_fill_reply,
+
+	.set_validate		= ethnl_set_linkmodes_validate,
+	.set			= ethnl_set_linkmodes,
+	.set_ntf_cmd		= ETHTOOL_MSG_LINKMODES_NTF,
+};