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/include/net/seg6.h b/include/net/seg6.h
new file mode 100644
index 000000000..82b3fbbcb
--- /dev/null
+++ b/include/net/seg6.h
@@ -0,0 +1,94 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ *  SR-IPv6 implementation
+ *
+ *  Author:
+ *  David Lebrun <david.lebrun@uclouvain.be>
+ */
+
+#ifndef _NET_SEG6_H
+#define _NET_SEG6_H
+
+#include <linux/net.h>
+#include <linux/ipv6.h>
+#include <linux/seg6.h>
+#include <linux/rhashtable-types.h>
+
+static inline void update_csum_diff4(struct sk_buff *skb, __be32 from,
+				     __be32 to)
+{
+	__be32 diff[] = { ~from, to };
+
+	skb->csum = ~csum_partial((char *)diff, sizeof(diff), ~skb->csum);
+}
+
+static inline void update_csum_diff16(struct sk_buff *skb, __be32 *from,
+				      __be32 *to)
+{
+	__be32 diff[] = {
+		~from[0], ~from[1], ~from[2], ~from[3],
+		to[0], to[1], to[2], to[3],
+	};
+
+	skb->csum = ~csum_partial((char *)diff, sizeof(diff), ~skb->csum);
+}
+
+struct seg6_pernet_data {
+	struct mutex lock;
+	struct in6_addr __rcu *tun_src;
+#ifdef CONFIG_IPV6_SEG6_HMAC
+	struct rhashtable hmac_infos;
+#endif
+};
+
+static inline struct seg6_pernet_data *seg6_pernet(struct net *net)
+{
+#if IS_ENABLED(CONFIG_IPV6)
+	return net->ipv6.seg6_data;
+#else
+	return NULL;
+#endif
+}
+
+extern int seg6_init(void);
+extern void seg6_exit(void);
+#ifdef CONFIG_IPV6_SEG6_LWTUNNEL
+extern int seg6_iptunnel_init(void);
+extern void seg6_iptunnel_exit(void);
+extern int seg6_local_init(void);
+extern void seg6_local_exit(void);
+#else
+static inline int seg6_iptunnel_init(void) { return 0; }
+static inline void seg6_iptunnel_exit(void) {}
+static inline int seg6_local_init(void) { return 0; }
+static inline void seg6_local_exit(void) {}
+#endif
+
+extern bool seg6_validate_srh(struct ipv6_sr_hdr *srh, int len, bool reduced);
+extern struct ipv6_sr_hdr *seg6_get_srh(struct sk_buff *skb, int flags);
+extern void seg6_icmp_srh(struct sk_buff *skb, struct inet6_skb_parm *opt);
+extern int seg6_do_srh_encap(struct sk_buff *skb, struct ipv6_sr_hdr *osrh,
+			     int proto);
+extern int seg6_do_srh_inline(struct sk_buff *skb, struct ipv6_sr_hdr *osrh);
+extern int seg6_lookup_nexthop(struct sk_buff *skb, struct in6_addr *nhaddr,
+			       u32 tbl_id);
+
+/* If the packet which invoked an ICMP error contains an SRH return
+ * the true destination address from within the SRH, otherwise use the
+ * destination address in the IP header.
+ */
+static inline const struct in6_addr *seg6_get_daddr(struct sk_buff *skb,
+						    struct inet6_skb_parm *opt)
+{
+	struct ipv6_sr_hdr *srh;
+
+	if (opt->flags & IP6SKB_SEG6) {
+		srh = (struct ipv6_sr_hdr *)(skb->data + opt->srhoff);
+		return  &srh->segments[0];
+	}
+
+	return NULL;
+}
+
+
+#endif