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, 95 insertions, 0 deletions

diff --git a/tools/perf/util/trigger.h b/tools/perf/util/trigger.h
new file mode 100644
index 000000000..33e997f9c
--- /dev/null
+++ b/tools/perf/util/trigger.h
@@ -0,0 +1,95 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __TRIGGER_H_
+#define __TRIGGER_H_ 1
+
+#include "asm/bug.h"
+
+/*
+ * Use trigger to model operations which need to be executed when
+ * an event (a signal, for example) is observed.
+ *
+ * States and transits:
+ *
+ *
+ *  OFF--> ON --> READY --(hit)--> HIT
+ *                 ^               |
+ *                 |            (ready)
+ *                 |               |
+ *                  \_____________/
+ *
+ * is_hit and is_ready are two key functions to query the state of
+ * a trigger. is_hit means the event already happen; is_ready means the
+ * trigger is waiting for the event.
+ */
+
+struct trigger {
+	volatile enum {
+		TRIGGER_ERROR		= -2,
+		TRIGGER_OFF		= -1,
+		TRIGGER_ON		= 0,
+		TRIGGER_READY		= 1,
+		TRIGGER_HIT		= 2,
+	} state;
+	const char *name;
+};
+
+#define TRIGGER_WARN_ONCE(t, exp) \
+	WARN_ONCE(t->state != exp, "trigger '%s' state transist error: %d in %s()\n", \
+		  t->name, t->state, __func__)
+
+static inline bool trigger_is_available(struct trigger *t)
+{
+	return t->state >= 0;
+}
+
+static inline bool trigger_is_error(struct trigger *t)
+{
+	return t->state <= TRIGGER_ERROR;
+}
+
+static inline void trigger_on(struct trigger *t)
+{
+	TRIGGER_WARN_ONCE(t, TRIGGER_OFF);
+	t->state = TRIGGER_ON;
+}
+
+static inline void trigger_ready(struct trigger *t)
+{
+	if (!trigger_is_available(t))
+		return;
+	t->state = TRIGGER_READY;
+}
+
+static inline void trigger_hit(struct trigger *t)
+{
+	if (!trigger_is_available(t))
+		return;
+	TRIGGER_WARN_ONCE(t, TRIGGER_READY);
+	t->state = TRIGGER_HIT;
+}
+
+static inline void trigger_off(struct trigger *t)
+{
+	if (!trigger_is_available(t))
+		return;
+	t->state = TRIGGER_OFF;
+}
+
+static inline void trigger_error(struct trigger *t)
+{
+	t->state = TRIGGER_ERROR;
+}
+
+static inline bool trigger_is_ready(struct trigger *t)
+{
+	return t->state == TRIGGER_READY;
+}
+
+static inline bool trigger_is_hit(struct trigger *t)
+{
+	return t->state == TRIGGER_HIT;
+}
+
+#define DEFINE_TRIGGER(n) \
+struct trigger n = {.state = TRIGGER_OFF, .name = #n}
+#endif