libceph: Remove VLA usage of skcipher

In the quest to remove all stack VLA usage from the kernel[1], this
replaces struct crypto_skcipher and SKCIPHER_REQUEST_ON_STACK() usage
with struct crypto_sync_skcipher and SYNC_SKCIPHER_REQUEST_ON_STACK(),
which uses a fixed stack size.

[1] https://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@mail.gmail.com

Cc: Ilya Dryomov <idryomov@gmail.com>
Cc: "Yan, Zheng" <zyan@redhat.com>
Cc: Sage Weil <sage@redhat.com>
Cc: ceph-devel@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/net/ceph/crypto.c b/net/ceph/crypto.c
index 02172c4..5d6724c 100644 (file)
--- a/net/ceph/crypto.c
+++ b/net/ceph/crypto.c
@@ -46,9 +46,9 @@ static int set_secret(struct ceph_crypto_key *key, void *buf)
                goto fail;
        }
 
-       /* crypto_alloc_skcipher() allocates with GFP_KERNEL */
+       /* crypto_alloc_sync_skcipher() allocates with GFP_KERNEL */
        noio_flag = memalloc_noio_save();
-       key->tfm = crypto_alloc_skcipher("cbc(aes)", 0, CRYPTO_ALG_ASYNC);
+       key->tfm = crypto_alloc_sync_skcipher("cbc(aes)", 0, 0);
        memalloc_noio_restore(noio_flag);
        if (IS_ERR(key->tfm)) {
                ret = PTR_ERR(key->tfm);
@@ -56,7 +56,7 @@ static int set_secret(struct ceph_crypto_key *key, void *buf)
                goto fail;
        }
 
-       ret = crypto_skcipher_setkey(key->tfm, key->key, key->len);
+       ret = crypto_sync_skcipher_setkey(key->tfm, key->key, key->len);
        if (ret)
                goto fail;
 
@@ -136,7 +136,7 @@ void ceph_crypto_key_destroy(struct ceph_crypto_key *key)
        if (key) {
                kfree(key->key);
                key->key = NULL;
-               crypto_free_skcipher(key->tfm);
+               crypto_free_sync_skcipher(key->tfm);
                key->tfm = NULL;
        }
 }
@@ -216,7 +216,7 @@ static void teardown_sgtable(struct sg_table *sgt)
 static int ceph_aes_crypt(const struct ceph_crypto_key *key, bool encrypt,
                          void *buf, int buf_len, int in_len, int *pout_len)
 {
-       SKCIPHER_REQUEST_ON_STACK(req, key->tfm);
+       SYNC_SKCIPHER_REQUEST_ON_STACK(req, key->tfm);
        struct sg_table sgt;
        struct scatterlist prealloc_sg;
        char iv[AES_BLOCK_SIZE] __aligned(8);
@@ -232,7 +232,7 @@ static int ceph_aes_crypt(const struct ceph_crypto_key *key, bool encrypt,
                return ret;
 
        memcpy(iv, aes_iv, AES_BLOCK_SIZE);
-       skcipher_request_set_tfm(req, key->tfm);
+       skcipher_request_set_sync_tfm(req, key->tfm);
        skcipher_request_set_callback(req, 0, NULL, NULL);
        skcipher_request_set_crypt(req, sgt.sgl, sgt.sgl, crypt_len, iv);
 

diff --git a/net/ceph/crypto.h b/net/ceph/crypto.h
index bb45c7d..96ef4d8 100644 (file)
--- a/net/ceph/crypto.h
+++ b/net/ceph/crypto.h
@@ -13,7 +13,7 @@ struct ceph_crypto_key {
        struct ceph_timespec created;
        int len;
        void *key;
-       struct crypto_skcipher *tfm;
+       struct crypto_sync_skcipher *tfm;
 };
 
 int ceph_crypto_key_clone(struct ceph_crypto_key *dst,