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, 31 insertions, 0 deletions

diff --git a/tools/include/asm-generic/bitops.h b/tools/include/asm-generic/bitops.h
new file mode 100644
index 000000000..9ab313e93
--- /dev/null
+++ b/tools/include/asm-generic/bitops.h
@@ -0,0 +1,31 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __TOOLS_ASM_GENERIC_BITOPS_H
+#define __TOOLS_ASM_GENERIC_BITOPS_H
+
+/*
+ * tools/ copied this from include/asm-generic/bitops.h, bit by bit as it needed
+ * some functions.
+ *
+ * For the benefit of those who are trying to port Linux to another
+ * architecture, here are some C-language equivalents.  You should
+ * recode these in the native assembly language, if at all possible.
+ *
+ * C language equivalents written by Theodore Ts'o, 9/26/92
+ */
+
+#include <asm-generic/bitops/__ffs.h>
+#include <asm-generic/bitops/__ffz.h>
+#include <asm-generic/bitops/fls.h>
+#include <asm-generic/bitops/__fls.h>
+#include <asm-generic/bitops/fls64.h>
+
+#ifndef _TOOLS_LINUX_BITOPS_H_
+#error only <linux/bitops.h> can be included directly
+#endif
+
+#include <asm-generic/bitops/hweight.h>
+
+#include <asm-generic/bitops/atomic.h>
+#include <asm-generic/bitops/non-atomic.h>
+
+#endif /* __TOOLS_ASM_GENERIC_BITOPS_H */