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, 73 insertions, 0 deletions

diff --git a/include/rv/kunit.h b/include/rv/kunit.h
new file mode 100644
index 000000000..31e0b93c4
--- /dev/null
+++ b/include/rv/kunit.h
@@ -0,0 +1,73 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2026-2029 Red Hat, Inc. Gabriele Monaco <gmonaco@redhat.com>
+ *
+ * Declaration of wrappers to allow mocking core functionality, like current,
+ * and other testing utilities.
+ * Necessary only when mocking may be needed. If the RV KUnit test is
+ * enabled, the wrappers incur an additional function call overhead.
+ */
+
+#ifndef _RV_KUNIT_H
+#define _RV_KUNIT_H
+
+#if IS_ENABLED(CONFIG_RV_MONITORS_KUNIT_TEST)
+
+#include <kunit/test.h>
+#include <kunit/test-bug.h>
+#include <linux/delay.h>
+
+int rv_set_testing(struct kunit_suite *suite);
+void rv_clear_testing(struct kunit_suite *suite);
+
+#define RV_KUNIT_MAX_MOCK_TASKS 8
+
+struct rv_kunit_ctx {
+	int reactions, expected;
+	int mock_task_count;
+	struct task_struct *mock_tasks[RV_KUNIT_MAX_MOCK_TASKS];
+};
+
+#define RV_KUNIT_EXPECT_REACTION(test, ctx)                             \
+	do {                                                            \
+		KUNIT_EXPECT_EQ(test, ctx->reactions, ++ctx->expected); \
+		if (ctx->reactions != ctx->expected)                    \
+			ctx->expected = ctx->reactions;                 \
+	} while (0)
+
+#define RV_KUNIT_EXPECT_NO_REACTION(test, ctx)                        \
+	do {                                                          \
+		KUNIT_EXPECT_EQ(test, ctx->reactions, ctx->expected); \
+		if (ctx->reactions != ctx->expected)                  \
+			ctx->expected = ctx->reactions;               \
+	} while (0)
+
+#define RV_KUNIT_EXPECT_REACTION_HERE(test, ctx)                             \
+	for (int __done = ({ RV_KUNIT_EXPECT_NO_REACTION(test, ctx); 0; });  \
+	     !__done;                                                        \
+	     __done = ({ RV_KUNIT_EXPECT_REACTION(test, ctx); 1; }))
+
+struct rv_kunit_mon {
+	struct rv_monitor *rv_this;
+	int (*monitor_init)(void);
+	void (*monitor_destroy)(void);
+	bool is_per_task;
+	int *task_slot;
+	void (*task_reset)(struct task_struct *task);
+};
+
+void prepare_test(struct kunit *test, const struct rv_kunit_mon *mon);
+void teardown_test(void *arg);
+struct task_struct *rv_kunit_alloc_mock_task(struct kunit *test);
+
+void rv_mock_current(struct task_struct *tsk);
+struct task_struct *rv_get_mock_current(void);
+
+#define rv_get_current() (unlikely(kunit_get_current_test()) ? rv_get_mock_current() : current)
+
+#else /* !CONFIG_RV_MONITORS_KUNIT_TEST */
+
+#define rv_get_current() current
+
+#endif /* CONFIG_RV_MONITORS_KUNIT_TEST */
+#endif /* _RV_KUNIT_H */