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, 55 insertions, 0 deletions

diff --git a/scripts/coccinelle/tests/doublebitand.cocci b/scripts/coccinelle/tests/doublebitand.cocci
new file mode 100644
index 000000000..025436a15
--- /dev/null
+++ b/scripts/coccinelle/tests/doublebitand.cocci
@@ -0,0 +1,55 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/// Find bit operations that include the same argument more than once
+//# One source of false positives is when the argument performs a side
+//# effect.  Another source of false positives is when a neutral value
+//# such as 0 for | is used to indicate no information, to maintain the
+//# same structure as other similar expressions
+///
+// Confidence: Moderate
+// Copyright: (C) 2010 Nicolas Palix, DIKU.
+// Copyright: (C) 2010 Julia Lawall, DIKU.
+// Copyright: (C) 2010 Gilles Muller, INRIA/LiP6.
+// URL: https://coccinelle.gitlabpages.inria.fr/website
+// Comments:
+// Options: --no-includes --include-headers
+
+virtual context
+virtual org
+virtual report
+
+@r expression@
+expression E;
+position p;
+@@
+
+(
+*        E@p
+         & ... & E
+|
+*        E@p
+         | ... | E
+|
+*        E@p
+         & ... & !E
+|
+*        E@p
+         | ... | !E
+|
+*        !E@p
+         & ... & E
+|
+*        !E@p
+         | ... | E
+)
+
+@script:python depends on org@
+p << r.p;
+@@
+
+cocci.print_main("duplicated argument to & or |",p)
+
+@script:python depends on report@
+p << r.p;
+@@
+
+coccilib.report.print_report(p[0],"duplicated argument to & or |")