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, 32 insertions, 0 deletions

diff --git a/tools/perf/util/spark.c b/tools/perf/util/spark.c
new file mode 100644
index 000000000..65ca253cc
--- /dev/null
+++ b/tools/perf/util/spark.c
@@ -0,0 +1,32 @@
+// SPDX-License-Identifier: GPL-2.0
+#include "spark.h"
+#include <limits.h>
+#include <linux/kernel.h>
+
+#define SPARK_SHIFT 8
+
+/* Print spark lines on outf for numval values in val. */
+int print_spark(char *bf, int size, unsigned long *val, int numval)
+{
+	static const char *ticks[NUM_SPARKS] = {
+		"▁",  "▂", "▃", "▄", "▅", "▆", "▇", "█"
+	};
+	int i, printed = 0;
+	unsigned long min = ULONG_MAX, max = 0, f;
+
+	for (i = 0; i < numval; i++) {
+		if (val[i] < min)
+			min = val[i];
+		if (val[i] > max)
+			max = val[i];
+	}
+	f = ((max - min) << SPARK_SHIFT) / (NUM_SPARKS - 1);
+	if (f < 1)
+		f = 1;
+	for (i = 0; i < numval; i++) {
+		printed += scnprintf(bf + printed, size - printed, "%s",
+				     ticks[((val[i] - min) << SPARK_SHIFT) / f]);
+	}
+
+	return printed;
+}