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/scripts/coccinelle/misc/doubleinit.cocci b/scripts/coccinelle/misc/doubleinit.cocci
new file mode 100644
index 000000000..7dbfde3f4
--- /dev/null
+++ b/scripts/coccinelle/misc/doubleinit.cocci
@@ -0,0 +1,54 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/// Find duplicate field initializations.  This has a high rate of false
+/// positives due to #ifdefs, which Coccinelle is not aware of in a structure
+/// initialization.
+///
+// Confidence: Low
+// Copyright: (C) 2010-2012 Nicolas Palix.
+// Copyright: (C) 2010-2012 Julia Lawall, INRIA/LIP6.
+// Copyright: (C) 2010-2012 Gilles Muller, INRIA/LiP6.
+// URL: https://coccinelle.gitlabpages.inria.fr/website
+// Comments: requires at least Coccinelle 0.2.4, lex or parse error otherwise
+// Options: --no-includes --include-headers
+
+virtual org
+virtual report
+
+@r@
+identifier I, s, fld;
+position p0,p;
+expression E;
+@@
+
+struct I s =@p0 { ..., .fld@p = E, ...};
+
+@s@
+identifier I, s, r.fld;
+position r.p0,p;
+expression E;
+@@
+
+struct I s =@p0 { ..., .fld@p = E, ...};
+
+@script:python depends on org@
+p0 << r.p0;
+fld << r.fld;
+ps << s.p;
+pr << r.p;
+@@
+
+if int(ps[0].line) < int(pr[0].line) or (int(ps[0].line) == int(pr[0].line) and int(ps[0].column) < int(pr[0].column)):
+  cocci.print_main(fld,p0)
+  cocci.print_secs("s",ps)
+  cocci.print_secs("r",pr)
+
+@script:python depends on report@
+p0 << r.p0;
+fld << r.fld;
+ps << s.p;
+pr << r.p;
+@@
+
+if int(ps[0].line) < int(pr[0].line) or (int(ps[0].line) == int(pr[0].line) and int(ps[0].column) < int(pr[0].column)):
+  msg = "%s: first occurrence line %s, second occurrence line %s" % (fld,ps[0].line,pr[0].line)
+  coccilib.report.print_report(p0[0],msg)