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>

1 files changed, 14 insertions, 60 deletions

diff --git a/include/crypto/akcipher.h b/include/crypto/akcipher.h
index 3dc05cf7e0a9..2d690494568c 100644
--- a/include/crypto/akcipher.h
+++ b/include/crypto/akcipher.h
@@ -271,62 +271,6 @@ static inline unsigned int crypto_akcipher_maxsize(struct crypto_akcipher *tfm)
 	return alg->max_size(tfm);
 }
 
-static inline void crypto_stat_akcipher_encrypt(struct akcipher_request *req,
-						int ret)
-{
-#ifdef CONFIG_CRYPTO_STATS
-	struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
-
-	if (ret && ret != -EINPROGRESS && ret != -EBUSY) {
-		atomic64_inc(&tfm->base.__crt_alg->akcipher_err_cnt);
-	} else {
-		atomic64_inc(&tfm->base.__crt_alg->encrypt_cnt);
-		atomic64_add(req->src_len, &tfm->base.__crt_alg->encrypt_tlen);
-	}
-#endif
-}
-
-static inline void crypto_stat_akcipher_decrypt(struct akcipher_request *req,
-						int ret)
-{
-#ifdef CONFIG_CRYPTO_STATS
-	struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
-
-	if (ret && ret != -EINPROGRESS && ret != -EBUSY) {
-		atomic64_inc(&tfm->base.__crt_alg->akcipher_err_cnt);
-	} else {
-		atomic64_inc(&tfm->base.__crt_alg->decrypt_cnt);
-		atomic64_add(req->src_len, &tfm->base.__crt_alg->decrypt_tlen);
-	}
-#endif
-}
-
-static inline void crypto_stat_akcipher_sign(struct akcipher_request *req,
-					     int ret)
-{
-#ifdef CONFIG_CRYPTO_STATS
-	struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
-
-	if (ret && ret != -EINPROGRESS && ret != -EBUSY)
-		atomic64_inc(&tfm->base.__crt_alg->akcipher_err_cnt);
-	else
-		atomic64_inc(&tfm->base.__crt_alg->sign_cnt);
-#endif
-}
-
-static inline void crypto_stat_akcipher_verify(struct akcipher_request *req,
-					       int ret)
-{
-#ifdef CONFIG_CRYPTO_STATS
-	struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
-
-	if (ret && ret != -EINPROGRESS && ret != -EBUSY)
-		atomic64_inc(&tfm->base.__crt_alg->akcipher_err_cnt);
-	else
-		atomic64_inc(&tfm->base.__crt_alg->verify_cnt);
-#endif
-}
-
 /**
  * crypto_akcipher_encrypt() - Invoke public key encrypt operation
  *
@@ -341,10 +285,13 @@ static inline int crypto_akcipher_encrypt(struct akcipher_request *req)
 {
 	struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
 	struct akcipher_alg *alg = crypto_akcipher_alg(tfm);
+	struct crypto_alg *calg = tfm->base.__crt_alg;
+	unsigned int src_len = req->src_len;
 	int ret;
 
+	crypto_stats_get(calg);
 	ret = alg->encrypt(req);
-	crypto_stat_akcipher_encrypt(req, ret);
+	crypto_stats_akcipher_encrypt(src_len, ret, calg);
 	return ret;
 }
 
@@ -362,10 +309,13 @@ static inline int crypto_akcipher_decrypt(struct akcipher_request *req)
 {
 	struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
 	struct akcipher_alg *alg = crypto_akcipher_alg(tfm);
+	struct crypto_alg *calg = tfm->base.__crt_alg;
+	unsigned int src_len = req->src_len;
 	int ret;
 
+	crypto_stats_get(calg);
 	ret = alg->decrypt(req);
-	crypto_stat_akcipher_decrypt(req, ret);
+	crypto_stats_akcipher_decrypt(src_len, ret, calg);
 	return ret;
 }
 
@@ -383,10 +333,12 @@ static inline int crypto_akcipher_sign(struct akcipher_request *req)
 {
 	struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
 	struct akcipher_alg *alg = crypto_akcipher_alg(tfm);
+	struct crypto_alg *calg = tfm->base.__crt_alg;
 	int ret;
 
+	crypto_stats_get(calg);
 	ret = alg->sign(req);
-	crypto_stat_akcipher_sign(req, ret);
+	crypto_stats_akcipher_sign(ret, calg);
 	return ret;
 }
 
@@ -404,10 +356,12 @@ static inline int crypto_akcipher_verify(struct akcipher_request *req)
 {
 	struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
 	struct akcipher_alg *alg = crypto_akcipher_alg(tfm);
+	struct crypto_alg *calg = tfm->base.__crt_alg;
 	int ret;
 
+	crypto_stats_get(calg);
 	ret = alg->verify(req);
-	crypto_stat_akcipher_verify(req, ret);
+	crypto_stats_akcipher_verify(ret, calg);
 	return ret;
 }