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, 318 insertions, 0 deletions

diff --git a/lib/tests/hashtable_test.c b/lib/tests/hashtable_test.c
new file mode 100644
index 000000000..3521de6ba
--- /dev/null
+++ b/lib/tests/hashtable_test.c
@@ -0,0 +1,318 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * KUnit test for the Kernel Hashtable structures.
+ *
+ * Copyright (C) 2022, Google LLC.
+ * Author: Rae Moar <rmoar@google.com>
+ */
+#include <kunit/test.h>
+
+#include <linux/hashtable.h>
+
+struct hashtable_test_entry {
+	int key;
+	int data;
+	struct hlist_node node;
+	int visited;
+};
+
+static void hashtable_test_hash_init(struct kunit *test)
+{
+	/* Test the different ways of initialising a hashtable. */
+	DEFINE_HASHTABLE(hash1, 2);
+	DECLARE_HASHTABLE(hash2, 3);
+
+	/* When using DECLARE_HASHTABLE, must use hash_init to
+	 * initialize the hashtable.
+	 */
+	hash_init(hash2);
+
+	KUNIT_EXPECT_TRUE(test, hash_empty(hash1));
+	KUNIT_EXPECT_TRUE(test, hash_empty(hash2));
+}
+
+static void hashtable_test_hash_empty(struct kunit *test)
+{
+	struct hashtable_test_entry a;
+	DEFINE_HASHTABLE(hash, 1);
+
+	KUNIT_EXPECT_TRUE(test, hash_empty(hash));
+
+	a.key = 1;
+	a.data = 13;
+	hash_add(hash, &a.node, a.key);
+
+	/* Hashtable should no longer be empty. */
+	KUNIT_EXPECT_FALSE(test, hash_empty(hash));
+}
+
+static void hashtable_test_hash_hashed(struct kunit *test)
+{
+	struct hashtable_test_entry a, b;
+	DEFINE_HASHTABLE(hash, 4);
+
+	a.key = 1;
+	a.data = 13;
+	hash_add(hash, &a.node, a.key);
+	b.key = 1;
+	b.data = 2;
+	hash_add(hash, &b.node, b.key);
+
+	KUNIT_EXPECT_TRUE(test, hash_hashed(&a.node));
+	KUNIT_EXPECT_TRUE(test, hash_hashed(&b.node));
+}
+
+static void hashtable_test_hash_add(struct kunit *test)
+{
+	struct hashtable_test_entry a, b, *x;
+	int bkt;
+	DEFINE_HASHTABLE(hash, 3);
+
+	a.key = 1;
+	a.data = 13;
+	a.visited = 0;
+	hash_add(hash, &a.node, a.key);
+	b.key = 2;
+	b.data = 10;
+	b.visited = 0;
+	hash_add(hash, &b.node, b.key);
+
+	hash_for_each(hash, bkt, x, node) {
+		x->visited++;
+		if (x->key == a.key)
+			KUNIT_EXPECT_EQ(test, x->data, 13);
+		else if (x->key == b.key)
+			KUNIT_EXPECT_EQ(test, x->data, 10);
+		else
+			KUNIT_FAIL(test, "Unexpected key in hashtable.");
+	}
+
+	/* Both entries should have been visited exactly once. */
+	KUNIT_EXPECT_EQ(test, a.visited, 1);
+	KUNIT_EXPECT_EQ(test, b.visited, 1);
+}
+
+static void hashtable_test_hash_del(struct kunit *test)
+{
+	struct hashtable_test_entry a, b, *x;
+	DEFINE_HASHTABLE(hash, 6);
+
+	a.key = 1;
+	a.data = 13;
+	hash_add(hash, &a.node, a.key);
+	b.key = 2;
+	b.data = 10;
+	b.visited = 0;
+	hash_add(hash, &b.node, b.key);
+
+	hash_del(&b.node);
+	hash_for_each_possible(hash, x, node, b.key) {
+		x->visited++;
+		KUNIT_EXPECT_NE(test, x->key, b.key);
+	}
+
+	/* The deleted entry should not have been visited. */
+	KUNIT_EXPECT_EQ(test, b.visited, 0);
+
+	hash_del(&a.node);
+
+	/* The hashtable should be empty. */
+	KUNIT_EXPECT_TRUE(test, hash_empty(hash));
+}
+
+static void hashtable_test_hash_for_each(struct kunit *test)
+{
+	struct hashtable_test_entry entries[3];
+	struct hashtable_test_entry *x;
+	int bkt, i, j, count;
+	DEFINE_HASHTABLE(hash, 3);
+
+	/* Add three entries to the hashtable. */
+	for (i = 0; i < 3; i++) {
+		entries[i].key = i;
+		entries[i].data = i + 10;
+		entries[i].visited = 0;
+		hash_add(hash, &entries[i].node, entries[i].key);
+	}
+
+	count = 0;
+	hash_for_each(hash, bkt, x, node) {
+		x->visited += 1;
+		KUNIT_ASSERT_GE_MSG(test, x->key, 0, "Unexpected key in hashtable.");
+		KUNIT_ASSERT_LT_MSG(test, x->key, 3, "Unexpected key in hashtable.");
+		count++;
+	}
+
+	/* Should have visited each entry exactly once. */
+	KUNIT_EXPECT_EQ(test, count, 3);
+	for (j = 0; j < 3; j++)
+		KUNIT_EXPECT_EQ(test, entries[j].visited, 1);
+}
+
+static void hashtable_test_hash_for_each_safe(struct kunit *test)
+{
+	struct hashtable_test_entry entries[3];
+	struct hashtable_test_entry *x;
+	struct hlist_node *tmp;
+	int bkt, i, j, count;
+	DEFINE_HASHTABLE(hash, 3);
+
+	/* Add three entries to the hashtable. */
+	for (i = 0; i < 3; i++) {
+		entries[i].key = i;
+		entries[i].data = i + 10;
+		entries[i].visited = 0;
+		hash_add(hash, &entries[i].node, entries[i].key);
+	}
+
+	count = 0;
+	hash_for_each_safe(hash, bkt, tmp, x, node) {
+		x->visited += 1;
+		KUNIT_ASSERT_GE_MSG(test, x->key, 0, "Unexpected key in hashtable.");
+		KUNIT_ASSERT_LT_MSG(test, x->key, 3, "Unexpected key in hashtable.");
+		count++;
+
+		/* Delete entry during loop. */
+		hash_del(&x->node);
+	}
+
+	/* Should have visited each entry exactly once. */
+	KUNIT_EXPECT_EQ(test, count, 3);
+	for (j = 0; j < 3; j++)
+		KUNIT_EXPECT_EQ(test, entries[j].visited, 1);
+}
+
+static void hashtable_test_hash_for_each_possible(struct kunit *test)
+{
+	struct hashtable_test_entry entries[4];
+	struct hashtable_test_entry *x, *y;
+	int buckets[2];
+	int bkt, i, j, count;
+	DEFINE_HASHTABLE(hash, 5);
+
+	/* Add three entries with key = 0 to the hashtable. */
+	for (i = 0; i < 3; i++) {
+		entries[i].key = 0;
+		entries[i].data = i;
+		entries[i].visited = 0;
+		hash_add(hash, &entries[i].node, entries[i].key);
+	}
+
+	/* Add an entry with key = 1. */
+	entries[3].key = 1;
+	entries[3].data = 3;
+	entries[3].visited = 0;
+	hash_add(hash, &entries[3].node, entries[3].key);
+
+	count = 0;
+	hash_for_each_possible(hash, x, node, 0) {
+		x->visited += 1;
+		KUNIT_ASSERT_GE_MSG(test, x->data, 0, "Unexpected data in hashtable.");
+		KUNIT_ASSERT_LT_MSG(test, x->data, 4, "Unexpected data in hashtable.");
+		count++;
+	}
+
+	/* Should have visited each entry with key = 0 exactly once. */
+	for (j = 0; j < 3; j++)
+		KUNIT_EXPECT_EQ(test, entries[j].visited, 1);
+
+	/* Save the buckets for the different keys. */
+	hash_for_each(hash, bkt, y, node) {
+		KUNIT_ASSERT_GE_MSG(test, y->key, 0, "Unexpected key in hashtable.");
+		KUNIT_ASSERT_LE_MSG(test, y->key, 1, "Unexpected key in hashtable.");
+		buckets[y->key] = bkt;
+	}
+
+	/* If entry with key = 1 is in the same bucket as the entries with
+	 * key = 0, check it was visited. Otherwise ensure that only three
+	 * entries were visited.
+	 */
+	if (buckets[0] == buckets[1]) {
+		KUNIT_EXPECT_EQ(test, count, 4);
+		KUNIT_EXPECT_EQ(test, entries[3].visited, 1);
+	} else {
+		KUNIT_EXPECT_EQ(test, count, 3);
+		KUNIT_EXPECT_EQ(test, entries[3].visited, 0);
+	}
+}
+
+static void hashtable_test_hash_for_each_possible_safe(struct kunit *test)
+{
+	struct hashtable_test_entry entries[4];
+	struct hashtable_test_entry *x, *y;
+	struct hlist_node *tmp;
+	int buckets[2];
+	int bkt, i, j, count;
+	DEFINE_HASHTABLE(hash, 5);
+
+	/* Add three entries with key = 0 to the hashtable. */
+	for (i = 0; i < 3; i++) {
+		entries[i].key = 0;
+		entries[i].data = i;
+		entries[i].visited = 0;
+		hash_add(hash, &entries[i].node, entries[i].key);
+	}
+
+	/* Add an entry with key = 1. */
+	entries[3].key = 1;
+	entries[3].data = 3;
+	entries[3].visited = 0;
+	hash_add(hash, &entries[3].node, entries[3].key);
+
+	count = 0;
+	hash_for_each_possible_safe(hash, x, tmp, node, 0) {
+		x->visited += 1;
+		KUNIT_ASSERT_GE_MSG(test, x->data, 0, "Unexpected data in hashtable.");
+		KUNIT_ASSERT_LT_MSG(test, x->data, 4, "Unexpected data in hashtable.");
+		count++;
+
+		/* Delete entry during loop. */
+		hash_del(&x->node);
+	}
+
+	/* Should have visited each entry with key = 0 exactly once. */
+	for (j = 0; j < 3; j++)
+		KUNIT_EXPECT_EQ(test, entries[j].visited, 1);
+
+	/* Save the buckets for the different keys. */
+	hash_for_each(hash, bkt, y, node) {
+		KUNIT_ASSERT_GE_MSG(test, y->key, 0, "Unexpected key in hashtable.");
+		KUNIT_ASSERT_LE_MSG(test, y->key, 1, "Unexpected key in hashtable.");
+		buckets[y->key] = bkt;
+	}
+
+	/* If entry with key = 1 is in the same bucket as the entries with
+	 * key = 0, check it was visited. Otherwise ensure that only three
+	 * entries were visited.
+	 */
+	if (buckets[0] == buckets[1]) {
+		KUNIT_EXPECT_EQ(test, count, 4);
+		KUNIT_EXPECT_EQ(test, entries[3].visited, 1);
+	} else {
+		KUNIT_EXPECT_EQ(test, count, 3);
+		KUNIT_EXPECT_EQ(test, entries[3].visited, 0);
+	}
+}
+
+static struct kunit_case hashtable_test_cases[] = {
+	KUNIT_CASE(hashtable_test_hash_init),
+	KUNIT_CASE(hashtable_test_hash_empty),
+	KUNIT_CASE(hashtable_test_hash_hashed),
+	KUNIT_CASE(hashtable_test_hash_add),
+	KUNIT_CASE(hashtable_test_hash_del),
+	KUNIT_CASE(hashtable_test_hash_for_each),
+	KUNIT_CASE(hashtable_test_hash_for_each_safe),
+	KUNIT_CASE(hashtable_test_hash_for_each_possible),
+	KUNIT_CASE(hashtable_test_hash_for_each_possible_safe),
+	{},
+};
+
+static struct kunit_suite hashtable_test_module = {
+	.name = "hashtable",
+	.test_cases = hashtable_test_cases,
+};
+
+kunit_test_suites(&hashtable_test_module);
+
+MODULE_DESCRIPTION("KUnit test for the Kernel Hashtable structures");
+MODULE_LICENSE("GPL");