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, 176 insertions, 0 deletions

diff --git a/drivers/leds/trigger/ledtrig-cpu.c b/drivers/leds/trigger/ledtrig-cpu.c
new file mode 100644
index 000000000..679323c2c
--- /dev/null
+++ b/drivers/leds/trigger/ledtrig-cpu.c
@@ -0,0 +1,176 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * ledtrig-cpu.c - LED trigger based on CPU activity
+ *
+ * This LED trigger will be registered for first 8 CPUs and named
+ * as cpu0..cpu7. There's additional trigger called cpu that
+ * is on when any CPU is active.
+ *
+ * If you want support for arbitrary number of CPUs, make it one trigger,
+ * with additional sysfs file selecting which CPU to watch.
+ *
+ * It can be bound to any LED just like other triggers using either a
+ * board file or via sysfs interface.
+ *
+ * An API named ledtrig_cpu is exported for any user, who want to add CPU
+ * activity indication in their code.
+ *
+ * Copyright 2011 Linus Walleij <linus.walleij@linaro.org>
+ * Copyright 2011 - 2012 Bryan Wu <bryan.wu@canonical.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/percpu.h>
+#include <linux/syscore_ops.h>
+#include <linux/rwsem.h>
+#include <linux/cpu.h>
+#include "../leds.h"
+
+#define MAX_NAME_LEN	8
+
+struct led_trigger_cpu {
+	bool is_active;
+	char name[MAX_NAME_LEN];
+	struct led_trigger *_trig;
+};
+
+static DEFINE_PER_CPU(struct led_trigger_cpu, cpu_trig);
+
+static struct led_trigger *trig_cpu_all;
+static atomic_t num_active_cpus = ATOMIC_INIT(0);
+
+/**
+ * ledtrig_cpu - emit a CPU event as a trigger
+ * @ledevt: CPU event to be emitted
+ *
+ * Emit a CPU event on a CPU core, which will trigger a
+ * bound LED to turn on or turn off.
+ */
+void ledtrig_cpu(enum cpu_led_event ledevt)
+{
+	struct led_trigger_cpu *trig = this_cpu_ptr(&cpu_trig);
+	bool is_active = trig->is_active;
+
+	/* Locate the correct CPU LED */
+	switch (ledevt) {
+	case CPU_LED_IDLE_END:
+	case CPU_LED_START:
+		/* Will turn the LED on, max brightness */
+		is_active = true;
+		break;
+
+	case CPU_LED_IDLE_START:
+	case CPU_LED_STOP:
+	case CPU_LED_HALTED:
+		/* Will turn the LED off */
+		is_active = false;
+		break;
+
+	default:
+		/* Will leave the LED as it is */
+		break;
+	}
+
+	if (is_active != trig->is_active) {
+		unsigned int active_cpus;
+		unsigned int total_cpus;
+
+		/* Update trigger state */
+		trig->is_active = is_active;
+		atomic_add(is_active ? 1 : -1, &num_active_cpus);
+		active_cpus = atomic_read(&num_active_cpus);
+		total_cpus = num_present_cpus();
+
+		led_trigger_event(trig->_trig,
+			is_active ? LED_FULL : LED_OFF);
+
+
+		led_trigger_event(trig_cpu_all,
+			DIV_ROUND_UP(LED_FULL * active_cpus, total_cpus));
+
+	}
+}
+EXPORT_SYMBOL(ledtrig_cpu);
+
+static int ledtrig_cpu_syscore_suspend(void *data)
+{
+	ledtrig_cpu(CPU_LED_STOP);
+	return 0;
+}
+
+static void ledtrig_cpu_syscore_resume(void *data)
+{
+	ledtrig_cpu(CPU_LED_START);
+}
+
+static void ledtrig_cpu_syscore_shutdown(void *data)
+{
+	ledtrig_cpu(CPU_LED_HALTED);
+}
+
+static const struct syscore_ops ledtrig_cpu_syscore_ops = {
+	.shutdown	= ledtrig_cpu_syscore_shutdown,
+	.suspend	= ledtrig_cpu_syscore_suspend,
+	.resume		= ledtrig_cpu_syscore_resume,
+};
+
+static struct syscore ledtrig_cpu_syscore = {
+	.ops = &ledtrig_cpu_syscore_ops,
+};
+
+static int ledtrig_online_cpu(unsigned int cpu)
+{
+	ledtrig_cpu(CPU_LED_START);
+	return 0;
+}
+
+static int ledtrig_prepare_down_cpu(unsigned int cpu)
+{
+	ledtrig_cpu(CPU_LED_STOP);
+	return 0;
+}
+
+static int __init ledtrig_cpu_init(void)
+{
+	unsigned int cpu;
+	int ret;
+
+	/* Supports up to 9999 cpu cores */
+	BUILD_BUG_ON(CONFIG_NR_CPUS > 9999);
+
+	/*
+	 * Registering a trigger for all CPUs.
+	 */
+	led_trigger_register_simple("cpu", &trig_cpu_all);
+
+	/*
+	 * Registering CPU led trigger for each CPU core here
+	 * ignores CPU hotplug, but after this CPU hotplug works
+	 * fine with this trigger.
+	 */
+	for_each_possible_cpu(cpu) {
+		struct led_trigger_cpu *trig = &per_cpu(cpu_trig, cpu);
+
+		if (cpu >= 8)
+			continue;
+
+		snprintf(trig->name, MAX_NAME_LEN, "cpu%u", cpu);
+
+		led_trigger_register_simple(trig->name, &trig->_trig);
+	}
+
+	register_syscore(&ledtrig_cpu_syscore);
+
+	ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "leds/trigger:starting",
+				ledtrig_online_cpu, ledtrig_prepare_down_cpu);
+	if (ret < 0)
+		pr_err("CPU hotplug notifier for ledtrig-cpu could not be registered: %d\n",
+		       ret);
+
+	pr_info("ledtrig-cpu: registered to indicate activity on CPUs\n");
+
+	return 0;
+}
+device_initcall(ledtrig_cpu_init);