crypto: user - fix use_after_free of struct xxx_request

All crypto_stats functions use the struct xxx_request for feeding stats,
but in some case this structure could already be freed.

For fixing this, the needed parameters (len and alg) will be stored
before the request being executed.
Fixes: cac5818c25d0 ("crypto: user - Implement a generic crypto statistics")
Reported-by: syzbot <syzbot+6939a606a5305e9e9799@syzkaller.appspotmail.com>

Signed-off-by: Corentin Labbe <clabbe@baylibre.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

3 files changed, 250 insertions, 4 deletions

diff --git a/crypto/ahash.c b/crypto/ahash.c
index 3a348fbcf8f91..5d320a811f750 100644
--- a/crypto/ahash.c
+++ b/crypto/ahash.c
@@ -364,20 +364,28 @@ static int crypto_ahash_op(struct ahash_request *req,
 
 int crypto_ahash_final(struct ahash_request *req)
 {
+	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
+	struct crypto_alg *alg = tfm->base.__crt_alg;
+	unsigned int nbytes = req->nbytes;
 	int ret;
 
+	crypto_stats_get(alg);
 	ret = crypto_ahash_op(req, crypto_ahash_reqtfm(req)->final);
-	crypto_stat_ahash_final(req, ret);
+	crypto_stats_ahash_final(nbytes, ret, alg);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(crypto_ahash_final);
 
 int crypto_ahash_finup(struct ahash_request *req)
 {
+	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
+	struct crypto_alg *alg = tfm->base.__crt_alg;
+	unsigned int nbytes = req->nbytes;
 	int ret;
 
+	crypto_stats_get(alg);
 	ret = crypto_ahash_op(req, crypto_ahash_reqtfm(req)->finup);
-	crypto_stat_ahash_final(req, ret);
+	crypto_stats_ahash_final(nbytes, ret, alg);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(crypto_ahash_finup);
@@ -385,13 +393,16 @@ EXPORT_SYMBOL_GPL(crypto_ahash_finup);
 int crypto_ahash_digest(struct ahash_request *req)
 {
 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
+	struct crypto_alg *alg = tfm->base.__crt_alg;
+	unsigned int nbytes = req->nbytes;
 	int ret;
 
+	crypto_stats_get(alg);
 	if (crypto_ahash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
 		ret = -ENOKEY;
 	else
 		ret = crypto_ahash_op(req, tfm->digest);
-	crypto_stat_ahash_final(req, ret);
+	crypto_stats_ahash_final(nbytes, ret, alg);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(crypto_ahash_digest);
diff --git a/crypto/algapi.c b/crypto/algapi.c
index 42fe316f80eea..4c1e6079d2714 100644
--- a/crypto/algapi.c
+++ b/crypto/algapi.c
@@ -1078,6 +1078,239 @@ int crypto_type_has_alg(const char *name, const struct crypto_type *frontend,
 }
 EXPORT_SYMBOL_GPL(crypto_type_has_alg);
 
+#ifdef CONFIG_CRYPTO_STATS
+void crypto_stats_get(struct crypto_alg *alg)
+{
+	crypto_alg_get(alg);
+}
+EXPORT_SYMBOL_GPL(crypto_stats_get);
+
+void crypto_stats_ablkcipher_encrypt(unsigned int nbytes, int ret,
+				     struct crypto_alg *alg)
+{
+	if (ret && ret != -EINPROGRESS && ret != -EBUSY) {
+		atomic64_inc(&alg->cipher_err_cnt);
+	} else {
+		atomic64_inc(&alg->encrypt_cnt);
+		atomic64_add(nbytes, &alg->encrypt_tlen);
+	}
+	crypto_alg_put(alg);
+}
+EXPORT_SYMBOL_GPL(crypto_stats_ablkcipher_encrypt);
+
+void crypto_stats_ablkcipher_decrypt(unsigned int nbytes, int ret,
+				     struct crypto_alg *alg)
+{
+	if (ret && ret != -EINPROGRESS && ret != -EBUSY) {
+		atomic64_inc(&alg->cipher_err_cnt);
+	} else {
+		atomic64_inc(&alg->decrypt_cnt);
+		atomic64_add(nbytes, &alg->decrypt_tlen);
+	}
+	crypto_alg_put(alg);
+}
+EXPORT_SYMBOL_GPL(crypto_stats_ablkcipher_decrypt);
+
+void crypto_stats_aead_encrypt(unsigned int cryptlen, struct crypto_alg *alg,
+			       int ret)
+{
+	if (ret && ret != -EINPROGRESS && ret != -EBUSY) {
+		atomic64_inc(&alg->aead_err_cnt);
+	} else {
+		atomic64_inc(&alg->encrypt_cnt);
+		atomic64_add(cryptlen, &alg->encrypt_tlen);
+	}
+	crypto_alg_put(alg);
+}
+EXPORT_SYMBOL_GPL(crypto_stats_aead_encrypt);
+
+void crypto_stats_aead_decrypt(unsigned int cryptlen, struct crypto_alg *alg,
+			       int ret)
+{
+	if (ret && ret != -EINPROGRESS && ret != -EBUSY) {
+		atomic64_inc(&alg->aead_err_cnt);
+	} else {
+		atomic64_inc(&alg->decrypt_cnt);
+		atomic64_add(cryptlen, &alg->decrypt_tlen);
+	}
+	crypto_alg_put(alg);
+}
+EXPORT_SYMBOL_GPL(crypto_stats_aead_decrypt);
+
+void crypto_stats_akcipher_encrypt(unsigned int src_len, int ret,
+				   struct crypto_alg *alg)
+{
+	if (ret && ret != -EINPROGRESS && ret != -EBUSY) {
+		atomic64_inc(&alg->akcipher_err_cnt);
+	} else {
+		atomic64_inc(&alg->encrypt_cnt);
+		atomic64_add(src_len, &alg->encrypt_tlen);
+	}
+	crypto_alg_put(alg);
+}
+EXPORT_SYMBOL_GPL(crypto_stats_akcipher_encrypt);
+
+void crypto_stats_akcipher_decrypt(unsigned int src_len, int ret,
+				   struct crypto_alg *alg)
+{
+	if (ret && ret != -EINPROGRESS && ret != -EBUSY) {
+		atomic64_inc(&alg->akcipher_err_cnt);
+	} else {
+		atomic64_inc(&alg->decrypt_cnt);
+		atomic64_add(src_len, &alg->decrypt_tlen);
+	}
+	crypto_alg_put(alg);
+}
+EXPORT_SYMBOL_GPL(crypto_stats_akcipher_decrypt);
+
+void crypto_stats_akcipher_sign(int ret, struct crypto_alg *alg)
+{
+	if (ret && ret != -EINPROGRESS && ret != -EBUSY)
+		atomic64_inc(&alg->akcipher_err_cnt);
+	else
+		atomic64_inc(&alg->sign_cnt);
+	crypto_alg_put(alg);
+}
+EXPORT_SYMBOL_GPL(crypto_stats_akcipher_sign);
+
+void crypto_stats_akcipher_verify(int ret, struct crypto_alg *alg)
+{
+	if (ret && ret != -EINPROGRESS && ret != -EBUSY)
+		atomic64_inc(&alg->akcipher_err_cnt);
+	else
+		atomic64_inc(&alg->verify_cnt);
+	crypto_alg_put(alg);
+}
+EXPORT_SYMBOL_GPL(crypto_stats_akcipher_verify);
+
+void crypto_stats_compress(unsigned int slen, int ret, struct crypto_alg *alg)
+{
+	if (ret && ret != -EINPROGRESS && ret != -EBUSY) {
+		atomic64_inc(&alg->compress_err_cnt);
+	} else {
+		atomic64_inc(&alg->compress_cnt);
+		atomic64_add(slen, &alg->compress_tlen);
+	}
+	crypto_alg_put(alg);
+}
+EXPORT_SYMBOL_GPL(crypto_stats_compress);
+
+void crypto_stats_decompress(unsigned int slen, int ret, struct crypto_alg *alg)
+{
+	if (ret && ret != -EINPROGRESS && ret != -EBUSY) {
+		atomic64_inc(&alg->compress_err_cnt);
+	} else {
+		atomic64_inc(&alg->decompress_cnt);
+		atomic64_add(slen, &alg->decompress_tlen);
+	}
+	crypto_alg_put(alg);
+}
+EXPORT_SYMBOL_GPL(crypto_stats_decompress);
+
+void crypto_stats_ahash_update(unsigned int nbytes, int ret,
+			       struct crypto_alg *alg)
+{
+	if (ret && ret != -EINPROGRESS && ret != -EBUSY)
+		atomic64_inc(&alg->hash_err_cnt);
+	else
+		atomic64_add(nbytes, &alg->hash_tlen);
+	crypto_alg_put(alg);
+}
+EXPORT_SYMBOL_GPL(crypto_stats_ahash_update);
+
+void crypto_stats_ahash_final(unsigned int nbytes, int ret,
+			      struct crypto_alg *alg)
+{
+	if (ret && ret != -EINPROGRESS && ret != -EBUSY) {
+		atomic64_inc(&alg->hash_err_cnt);
+	} else {
+		atomic64_inc(&alg->hash_cnt);
+		atomic64_add(nbytes, &alg->hash_tlen);
+	}
+	crypto_alg_put(alg);
+}
+EXPORT_SYMBOL_GPL(crypto_stats_ahash_final);
+
+void crypto_stats_kpp_set_secret(struct crypto_alg *alg, int ret)
+{
+	if (ret)
+		atomic64_inc(&alg->kpp_err_cnt);
+	else
+		atomic64_inc(&alg->setsecret_cnt);
+	crypto_alg_put(alg);
+}
+EXPORT_SYMBOL_GPL(crypto_stats_kpp_set_secret);
+
+void crypto_stats_kpp_generate_public_key(struct crypto_alg *alg, int ret)
+{
+	if (ret)
+		atomic64_inc(&alg->kpp_err_cnt);
+	else
+		atomic64_inc(&alg->generate_public_key_cnt);
+	crypto_alg_put(alg);
+}
+EXPORT_SYMBOL_GPL(crypto_stats_kpp_generate_public_key);
+
+void crypto_stats_kpp_compute_shared_secret(struct crypto_alg *alg, int ret)
+{
+	if (ret)
+		atomic64_inc(&alg->kpp_err_cnt);
+	else
+		atomic64_inc(&alg->compute_shared_secret_cnt);
+	crypto_alg_put(alg);
+}
+EXPORT_SYMBOL_GPL(crypto_stats_kpp_compute_shared_secret);
+
+void crypto_stats_rng_seed(struct crypto_alg *alg, int ret)
+{
+	if (ret && ret != -EINPROGRESS && ret != -EBUSY)
+		atomic64_inc(&alg->rng_err_cnt);
+	else
+		atomic64_inc(&alg->seed_cnt);
+	crypto_alg_put(alg);
+}
+EXPORT_SYMBOL_GPL(crypto_stats_rng_seed);
+
+void crypto_stats_rng_generate(struct crypto_alg *alg, unsigned int dlen,
+			       int ret)
+{
+	if (ret && ret != -EINPROGRESS && ret != -EBUSY) {
+		atomic64_inc(&alg->rng_err_cnt);
+	} else {
+		atomic64_inc(&alg->generate_cnt);
+		atomic64_add(dlen, &alg->generate_tlen);
+	}
+	crypto_alg_put(alg);
+}
+EXPORT_SYMBOL_GPL(crypto_stats_rng_generate);
+
+void crypto_stats_skcipher_encrypt(unsigned int cryptlen, int ret,
+				   struct crypto_alg *alg)
+{
+	if (ret && ret != -EINPROGRESS && ret != -EBUSY) {
+		atomic64_inc(&alg->cipher_err_cnt);
+	} else {
+		atomic64_inc(&alg->encrypt_cnt);
+		atomic64_add(cryptlen, &alg->encrypt_tlen);
+	}
+	crypto_alg_put(alg);
+}
+EXPORT_SYMBOL_GPL(crypto_stats_skcipher_encrypt);
+
+void crypto_stats_skcipher_decrypt(unsigned int cryptlen, int ret,
+				   struct crypto_alg *alg)
+{
+	if (ret && ret != -EINPROGRESS && ret != -EBUSY) {
+		atomic64_inc(&alg->cipher_err_cnt);
+	} else {
+		atomic64_inc(&alg->decrypt_cnt);
+		atomic64_add(cryptlen, &alg->decrypt_tlen);
+	}
+	crypto_alg_put(alg);
+}
+EXPORT_SYMBOL_GPL(crypto_stats_skcipher_decrypt);
+#endif
+
 static int __init crypto_algapi_init(void)
 {
 	crypto_init_proc();
diff --git a/crypto/rng.c b/crypto/rng.c
index 2406501b90b70..33c38a72bff59 100644
--- a/crypto/rng.c
+++ b/crypto/rng.c
@@ -35,9 +35,11 @@ static int crypto_default_rng_refcnt;
 
 int crypto_rng_reset(struct crypto_rng *tfm, const u8 *seed, unsigned int slen)
 {
+	struct crypto_alg *alg = tfm->base.__crt_alg;
 	u8 *buf = NULL;
 	int err;
 
+	crypto_stats_get(alg);
 	if (!seed && slen) {
 		buf = kmalloc(slen, GFP_KERNEL);
 		if (!buf)
@@ -50,7 +52,7 @@ int crypto_rng_reset(struct crypto_rng *tfm, const u8 *seed, unsigned int slen)
 	}
 
 	err = crypto_rng_alg(tfm)->seed(tfm, seed, slen);
-	crypto_stat_rng_seed(tfm, err);
+	crypto_stats_rng_seed(alg, err);
 out:
 	kzfree(buf);
 	return err;