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, 54 insertions, 0 deletions

diff --git a/tools/lib/slab.c b/tools/lib/slab.c
new file mode 100644
index 000000000..981a21404
--- /dev/null
+++ b/tools/lib/slab.c
@@ -0,0 +1,54 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <stdio.h>
+#include <string.h>
+
+#include <urcu/uatomic.h>
+#include <linux/slab.h>
+#include <malloc.h>
+#include <linux/gfp.h>
+
+int kmalloc_nr_allocated;
+int kmalloc_verbose;
+
+void *kmalloc(size_t size, gfp_t gfp)
+{
+	void *ret;
+
+	if (!(gfp & __GFP_DIRECT_RECLAIM))
+		return NULL;
+
+	ret = malloc(size);
+	uatomic_inc(&kmalloc_nr_allocated);
+	if (kmalloc_verbose)
+		printf("Allocating %p from malloc\n", ret);
+	if (gfp & __GFP_ZERO)
+		memset(ret, 0, size);
+	return ret;
+}
+
+void kfree(void *p)
+{
+	if (!p)
+		return;
+	uatomic_dec(&kmalloc_nr_allocated);
+	if (kmalloc_verbose)
+		printf("Freeing %p to malloc\n", p);
+	free(p);
+}
+
+void *kmalloc_array(size_t n, size_t size, gfp_t gfp)
+{
+	void *ret;
+
+	if (!(gfp & __GFP_DIRECT_RECLAIM))
+		return NULL;
+
+	ret = calloc(n, size);
+	uatomic_inc(&kmalloc_nr_allocated);
+	if (kmalloc_verbose)
+		printf("Allocating %p from calloc\n", ret);
+	if (gfp & __GFP_ZERO)
+		memset(ret, 0, n * size);
+	return ret;
+}