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, 228 insertions, 0 deletions

diff --git a/crypto/ecb.c b/crypto/ecb.c
new file mode 100644
index 000000000..cd1b20456
--- /dev/null
+++ b/crypto/ecb.c
@@ -0,0 +1,228 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * ECB: Electronic CodeBook mode
+ *
+ * Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
+ */
+
+#include <crypto/internal/cipher.h>
+#include <crypto/internal/skcipher.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+
+static int crypto_ecb_crypt(struct crypto_cipher *cipher, const u8 *src,
+			    u8 *dst, unsigned nbytes, bool final,
+			    void (*fn)(struct crypto_tfm *, u8 *, const u8 *))
+{
+	const unsigned int bsize = crypto_cipher_blocksize(cipher);
+
+	while (nbytes >= bsize) {
+		fn(crypto_cipher_tfm(cipher), dst, src);
+
+		src += bsize;
+		dst += bsize;
+
+		nbytes -= bsize;
+	}
+
+	return nbytes && final ? -EINVAL : nbytes;
+}
+
+static int crypto_ecb_encrypt2(struct crypto_lskcipher *tfm, const u8 *src,
+			       u8 *dst, unsigned len, u8 *iv, u32 flags)
+{
+	struct crypto_cipher **ctx = crypto_lskcipher_ctx(tfm);
+	struct crypto_cipher *cipher = *ctx;
+
+	return crypto_ecb_crypt(cipher, src, dst, len,
+				flags & CRYPTO_LSKCIPHER_FLAG_FINAL,
+				crypto_cipher_alg(cipher)->cia_encrypt);
+}
+
+static int crypto_ecb_decrypt2(struct crypto_lskcipher *tfm, const u8 *src,
+			       u8 *dst, unsigned len, u8 *iv, u32 flags)
+{
+	struct crypto_cipher **ctx = crypto_lskcipher_ctx(tfm);
+	struct crypto_cipher *cipher = *ctx;
+
+	return crypto_ecb_crypt(cipher, src, dst, len,
+				flags & CRYPTO_LSKCIPHER_FLAG_FINAL,
+				crypto_cipher_alg(cipher)->cia_decrypt);
+}
+
+static int lskcipher_setkey_simple2(struct crypto_lskcipher *tfm,
+				    const u8 *key, unsigned int keylen)
+{
+	struct crypto_cipher **ctx = crypto_lskcipher_ctx(tfm);
+	struct crypto_cipher *cipher = *ctx;
+
+	crypto_cipher_clear_flags(cipher, CRYPTO_TFM_REQ_MASK);
+	crypto_cipher_set_flags(cipher, crypto_lskcipher_get_flags(tfm) &
+				CRYPTO_TFM_REQ_MASK);
+	return crypto_cipher_setkey(cipher, key, keylen);
+}
+
+static int lskcipher_init_tfm_simple2(struct crypto_lskcipher *tfm)
+{
+	struct lskcipher_instance *inst = lskcipher_alg_instance(tfm);
+	struct crypto_cipher **ctx = crypto_lskcipher_ctx(tfm);
+	struct crypto_cipher_spawn *spawn;
+	struct crypto_cipher *cipher;
+
+	spawn = lskcipher_instance_ctx(inst);
+	cipher = crypto_spawn_cipher(spawn);
+	if (IS_ERR(cipher))
+		return PTR_ERR(cipher);
+
+	*ctx = cipher;
+	return 0;
+}
+
+static void lskcipher_exit_tfm_simple2(struct crypto_lskcipher *tfm)
+{
+	struct crypto_cipher **ctx = crypto_lskcipher_ctx(tfm);
+
+	crypto_free_cipher(*ctx);
+}
+
+static void lskcipher_free_instance_simple2(struct lskcipher_instance *inst)
+{
+	crypto_drop_cipher(lskcipher_instance_ctx(inst));
+	kfree(inst);
+}
+
+static struct lskcipher_instance *lskcipher_alloc_instance_simple2(
+	struct crypto_template *tmpl, struct rtattr **tb)
+{
+	struct crypto_cipher_spawn *spawn;
+	struct lskcipher_instance *inst;
+	struct crypto_alg *cipher_alg;
+	u32 mask;
+	int err;
+
+	err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_LSKCIPHER, &mask);
+	if (err)
+		return ERR_PTR(err);
+
+	inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
+	if (!inst)
+		return ERR_PTR(-ENOMEM);
+	spawn = lskcipher_instance_ctx(inst);
+
+	err = crypto_grab_cipher(spawn, lskcipher_crypto_instance(inst),
+				 crypto_attr_alg_name(tb[1]), 0, mask);
+	if (err)
+		goto err_free_inst;
+	cipher_alg = crypto_spawn_cipher_alg(spawn);
+
+	err = crypto_inst_setname(lskcipher_crypto_instance(inst), tmpl->name,
+				  cipher_alg);
+	if (err)
+		goto err_free_inst;
+
+	inst->free = lskcipher_free_instance_simple2;
+
+	/* Default algorithm properties, can be overridden */
+	inst->alg.co.base.cra_blocksize = cipher_alg->cra_blocksize;
+	inst->alg.co.base.cra_alignmask = cipher_alg->cra_alignmask;
+	inst->alg.co.base.cra_priority = cipher_alg->cra_priority;
+	inst->alg.co.min_keysize = cipher_alg->cra_cipher.cia_min_keysize;
+	inst->alg.co.max_keysize = cipher_alg->cra_cipher.cia_max_keysize;
+	inst->alg.co.ivsize = cipher_alg->cra_blocksize;
+
+	/* Use struct crypto_cipher * by default, can be overridden */
+	inst->alg.co.base.cra_ctxsize = sizeof(struct crypto_cipher *);
+	inst->alg.setkey = lskcipher_setkey_simple2;
+	inst->alg.init = lskcipher_init_tfm_simple2;
+	inst->alg.exit = lskcipher_exit_tfm_simple2;
+
+	return inst;
+
+err_free_inst:
+	lskcipher_free_instance_simple2(inst);
+	return ERR_PTR(err);
+}
+
+static int crypto_ecb_create2(struct crypto_template *tmpl, struct rtattr **tb)
+{
+	struct lskcipher_instance *inst;
+	int err;
+
+	inst = lskcipher_alloc_instance_simple2(tmpl, tb);
+	if (IS_ERR(inst))
+		return PTR_ERR(inst);
+
+	/* ECB mode doesn't take an IV */
+	inst->alg.co.ivsize = 0;
+
+	inst->alg.encrypt = crypto_ecb_encrypt2;
+	inst->alg.decrypt = crypto_ecb_decrypt2;
+
+	err = lskcipher_register_instance(tmpl, inst);
+	if (err)
+		inst->free(inst);
+
+	return err;
+}
+
+static int crypto_ecb_create(struct crypto_template *tmpl, struct rtattr **tb)
+{
+	struct crypto_lskcipher_spawn *spawn;
+	struct lskcipher_alg *cipher_alg;
+	struct lskcipher_instance *inst;
+	int err;
+
+	inst = lskcipher_alloc_instance_simple(tmpl, tb);
+	if (IS_ERR(inst)) {
+		err = crypto_ecb_create2(tmpl, tb);
+		return err;
+	}
+
+	spawn = lskcipher_instance_ctx(inst);
+	cipher_alg = crypto_lskcipher_spawn_alg(spawn);
+
+	/* ECB mode doesn't take an IV */
+	inst->alg.co.ivsize = 0;
+	if (cipher_alg->co.ivsize)
+		return -EINVAL;
+
+	inst->alg.co.base.cra_ctxsize = cipher_alg->co.base.cra_ctxsize;
+	inst->alg.setkey = cipher_alg->setkey;
+	inst->alg.encrypt = cipher_alg->encrypt;
+	inst->alg.decrypt = cipher_alg->decrypt;
+	inst->alg.init = cipher_alg->init;
+	inst->alg.exit = cipher_alg->exit;
+
+	err = lskcipher_register_instance(tmpl, inst);
+	if (err)
+		inst->free(inst);
+
+	return err;
+}
+
+static struct crypto_template crypto_ecb_tmpl = {
+	.name = "ecb",
+	.create = crypto_ecb_create,
+	.module = THIS_MODULE,
+};
+
+static int __init crypto_ecb_module_init(void)
+{
+	return crypto_register_template(&crypto_ecb_tmpl);
+}
+
+static void __exit crypto_ecb_module_exit(void)
+{
+	crypto_unregister_template(&crypto_ecb_tmpl);
+}
+
+module_init(crypto_ecb_module_init);
+module_exit(crypto_ecb_module_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("ECB block cipher mode of operation");
+MODULE_ALIAS_CRYPTO("ecb");
+MODULE_IMPORT_NS("CRYPTO_INTERNAL");