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, 70 insertions, 0 deletions

diff --git a/tools/cgroup/memcg_shrinker.py b/tools/cgroup/memcg_shrinker.py
new file mode 100644
index 000000000..e81c3017a
--- /dev/null
+++ b/tools/cgroup/memcg_shrinker.py
@@ -0,0 +1,70 @@
+#!/usr/bin/env python3
+#
+# Copyright (C) 2022 Roman Gushchin <roman.gushchin@linux.dev>
+# Copyright (C) 2022 Meta
+
+import os
+import argparse
+
+
+def scan_cgroups(cgroup_root):
+    cgroups = {}
+
+    for root, subdirs, _ in os.walk(cgroup_root):
+        for cgroup in subdirs:
+            path = os.path.join(root, cgroup)
+            ino = os.stat(path).st_ino
+            cgroups[ino] = path
+
+    # (memcg ino, path)
+    return cgroups
+
+
+def scan_shrinkers(shrinker_debugfs):
+    shrinkers = []
+
+    for root, subdirs, _ in os.walk(shrinker_debugfs):
+        for shrinker in subdirs:
+            count_path = os.path.join(root, shrinker, "count")
+            with open(count_path) as f:
+                for line in f.readlines():
+                    items = line.split(' ')
+                    ino = int(items[0])
+                    # (count, shrinker, memcg ino)
+                    shrinkers.append((int(items[1]), shrinker, ino))
+    return shrinkers
+
+
+def main():
+    parser = argparse.ArgumentParser(description='Display biggest shrinkers')
+    parser.add_argument('-n', '--lines', type=int, help='Number of lines to print')
+
+    args = parser.parse_args()
+
+    cgroups = scan_cgroups("/sys/fs/cgroup/")
+    shrinkers = scan_shrinkers("/sys/kernel/debug/shrinker/")
+    shrinkers.sort(reverse = True, key = lambda x: x[0])
+
+    n = 0
+    for s in shrinkers:
+        count, name, ino = (s[0], s[1], s[2])
+        if count == 0:
+            break
+
+        if ino == 0 or ino == 1:
+            cg = "/"
+        else:
+            try:
+                cg = cgroups[ino]
+            except KeyError:
+                cg = "unknown (%d)" % ino
+
+        print("%-8s %-20s %s" % (count, name, cg))
+
+        n += 1
+        if args.lines and n >= args.lines:
+            break
+
+
+if __name__ == '__main__':
+    main()