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, 123 insertions, 0 deletions

diff --git a/tools/bpf/bpftool/iter.c b/tools/bpf/bpftool/iter.c
new file mode 100644
index 000000000..df5f0d1e0
--- /dev/null
+++ b/tools/bpf/bpftool/iter.c
@@ -0,0 +1,123 @@
+// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+// Copyright (C) 2020 Facebook
+
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE
+#endif
+#include <errno.h>
+#include <unistd.h>
+#include <linux/err.h>
+#include <bpf/libbpf.h>
+
+#include "main.h"
+
+static int do_pin(int argc, char **argv)
+{
+	DECLARE_LIBBPF_OPTS(bpf_iter_attach_opts, iter_opts);
+	union bpf_iter_link_info linfo;
+	const char *objfile, *path;
+	struct bpf_program *prog;
+	struct bpf_object *obj;
+	struct bpf_link *link;
+	int err = -1, map_fd = -1;
+
+	if (!REQ_ARGS(2))
+		usage();
+
+	objfile = GET_ARG();
+	path = GET_ARG();
+
+	/* optional arguments */
+	if (argc) {
+		if (is_prefix(*argv, "map")) {
+			NEXT_ARG();
+
+			if (!REQ_ARGS(2)) {
+				p_err("incorrect map spec");
+				return -1;
+			}
+
+			map_fd = map_parse_fd(&argc, &argv, BPF_F_RDONLY);
+			if (map_fd < 0)
+				return -1;
+
+			memset(&linfo, 0, sizeof(linfo));
+			linfo.map.map_fd = map_fd;
+			iter_opts.link_info = &linfo;
+			iter_opts.link_info_len = sizeof(linfo);
+		}
+	}
+
+	obj = bpf_object__open(objfile);
+	if (!obj) {
+		err = -errno;
+		p_err("can't open objfile %s", objfile);
+		goto close_map_fd;
+	}
+
+	err = bpf_object__load(obj);
+	if (err) {
+		p_err("can't load objfile %s", objfile);
+		goto close_obj;
+	}
+
+	prog = bpf_object__next_program(obj, NULL);
+	if (!prog) {
+		err = -errno;
+		p_err("can't find bpf program in objfile %s", objfile);
+		goto close_obj;
+	}
+
+	link = bpf_program__attach_iter(prog, &iter_opts);
+	if (!link) {
+		err = -errno;
+		p_err("attach_iter failed for program %s",
+		      bpf_program__name(prog));
+		goto close_obj;
+	}
+
+	err = mount_bpffs_for_file(path);
+	if (err)
+		goto close_link;
+
+	err = bpf_link__pin(link, path);
+	if (err) {
+		p_err("pin_iter failed for program %s to path %s",
+		      bpf_program__name(prog), path);
+		goto close_link;
+	}
+
+close_link:
+	bpf_link__destroy(link);
+close_obj:
+	bpf_object__close(obj);
+close_map_fd:
+	if (map_fd >= 0)
+		close(map_fd);
+	return err;
+}
+
+static int do_help(int argc, char **argv)
+{
+	fprintf(stderr,
+		"Usage: %1$s %2$s pin OBJ PATH [map MAP]\n"
+		"       %1$s %2$s help\n"
+		"\n"
+		"       " HELP_SPEC_MAP "\n"
+		"       " HELP_SPEC_OPTIONS " }\n"
+		"",
+		bin_name, "iter");
+
+	return 0;
+}
+
+static const struct cmd cmds[] = {
+	{ "help",	do_help },
+	{ "pin",	do_pin },
+	{ 0 }
+};
+
+int do_iter(int argc, char **argv)
+{
+	return cmd_select(cmds, argc, argv, do_help);
+}