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, 62 insertions, 0 deletions

diff --git a/tools/perf/util/evswitch.c b/tools/perf/util/evswitch.c
new file mode 100644
index 000000000..d4c06a3f8
--- /dev/null
+++ b/tools/perf/util/evswitch.c
@@ -0,0 +1,62 @@
+// SPDX-License-Identifier: GPL-2.0-only
+// Copyright (C) 2019, Red Hat Inc, Arnaldo Carvalho de Melo <acme@redhat.com>
+
+#include <errno.h>
+#include "evswitch.h"
+#include "evlist.h"
+
+bool evswitch__discard(struct evswitch *evswitch, struct evsel *evsel)
+{
+	if (evswitch->on && evswitch->discarding) {
+		if (evswitch->on != evsel)
+			return true;
+
+		evswitch->discarding = false;
+
+		if (!evswitch->show_on_off_events)
+			return true;
+
+		return false;
+	}
+
+	if (evswitch->off && !evswitch->discarding) {
+		if (evswitch->off != evsel)
+			return false;
+
+		evswitch->discarding = true;
+
+		if (!evswitch->show_on_off_events)
+			return true;
+	}
+
+	return false;
+}
+
+static int evswitch__fprintf_enoent(FILE *fp, const char *evtype, const char *evname)
+{
+	int printed = fprintf(fp, "ERROR: switch-%s event not found (%s)\n", evtype, evname);
+
+	return printed += fprintf(fp, "HINT:  use 'perf evlist' to see the available event names\n");
+}
+
+int evswitch__init(struct evswitch *evswitch, struct evlist *evlist, FILE *fp)
+{
+	if (evswitch->on_name) {
+		evswitch->on = evlist__find_evsel_by_str(evlist, evswitch->on_name);
+		if (evswitch->on == NULL) {
+			evswitch__fprintf_enoent(fp, "on", evswitch->on_name);
+			return -ENOENT;
+		}
+		evswitch->discarding = true;
+	}
+
+	if (evswitch->off_name) {
+		evswitch->off = evlist__find_evsel_by_str(evlist, evswitch->off_name);
+		if (evswitch->off == NULL) {
+			evswitch__fprintf_enoent(fp, "off", evswitch->off_name);
+			return -ENOENT;
+		}
+	}
+
+	return 0;
+}