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, 71 insertions, 0 deletions

diff --git a/tools/perf/util/rwsem.c b/tools/perf/util/rwsem.c
new file mode 100644
index 000000000..9d2683239
--- /dev/null
+++ b/tools/perf/util/rwsem.c
@@ -0,0 +1,71 @@
+// SPDX-License-Identifier: GPL-2.0
+#include "util.h"
+#include "rwsem.h"
+
+#if RWS_ERRORCHECK
+#include "mutex.h"
+#endif
+
+int init_rwsem(struct rw_semaphore *sem)
+{
+#if RWS_ERRORCHECK
+	mutex_init(&sem->mtx);
+	return 0;
+#else
+	return pthread_rwlock_init(&sem->lock, NULL);
+#endif
+}
+
+int exit_rwsem(struct rw_semaphore *sem)
+{
+#if RWS_ERRORCHECK
+	mutex_destroy(&sem->mtx);
+	return 0;
+#else
+	return pthread_rwlock_destroy(&sem->lock);
+#endif
+}
+
+int down_read(struct rw_semaphore *sem)
+	NO_THREAD_SAFETY_ANALYSIS
+{
+#if RWS_ERRORCHECK
+	mutex_lock(&sem->mtx);
+	return 0;
+#else
+	return perf_singlethreaded ? 0 : pthread_rwlock_rdlock(&sem->lock);
+#endif
+}
+
+int up_read(struct rw_semaphore *sem)
+	NO_THREAD_SAFETY_ANALYSIS
+{
+#if RWS_ERRORCHECK
+	mutex_unlock(&sem->mtx);
+	return 0;
+#else
+	return perf_singlethreaded ? 0 : pthread_rwlock_unlock(&sem->lock);
+#endif
+}
+
+int down_write(struct rw_semaphore *sem)
+	NO_THREAD_SAFETY_ANALYSIS
+{
+#if RWS_ERRORCHECK
+	mutex_lock(&sem->mtx);
+	return 0;
+#else
+	return perf_singlethreaded ? 0 : pthread_rwlock_wrlock(&sem->lock);
+#endif
+}
+
+int up_write(struct rw_semaphore *sem)
+	NO_THREAD_SAFETY_ANALYSIS
+{
+#if RWS_ERRORCHECK
+	mutex_unlock(&sem->mtx);
+	return 0;
+#else
+	return perf_singlethreaded ? 0 : pthread_rwlock_unlock(&sem->lock);
+#endif
+}