crypto: testmgr - Dynamically allocate xbuf and axbuf

We currently allocate temporary memory that is used for testing
statically.  This renders the testing engine non-reentrant. As
algorithms may nest, i.e., one may construct another in order to
carry out a part of its operation, this is unacceptable.  For
example, it has been reported that an AEAD implementation allocates
a cipher in its setkey function, which causes it to fail during
testing as the temporary memory is overwritten.

This patch replaces the static memory with dynamically allocated
buffers.  We need a maximum of 16 pages so this slightly increases
the chances of an algorithm failing due to memory shortage.
However, as testing usually occurs at registration, this shouldn't
be a big problem.

Reported-by: Shasi Pulijala <spulijala@amcc.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 60 insertions, 48 deletions

diff --git a/crypto/testmgr.c b/crypto/testmgr.c
index e76af78d2fa0..c5550943411d 100644
--- a/crypto/testmgr.c
+++ b/crypto/testmgr.c
@@ -107,9 +107,6 @@ struct alg_test_desc {
 
 static unsigned int IDX[8] = { IDX1, IDX2, IDX3, IDX4, IDX5, IDX6, IDX7, IDX8 };
 
-static char *xbuf[XBUFSIZE];
-static char *axbuf[XBUFSIZE];
-
 static void hexdump(unsigned char *buf, unsigned int len)
 {
         print_hex_dump(KERN_CONT, "", DUMP_PREFIX_OFFSET,
@@ -128,6 +125,33 @@ static void tcrypt_complete(struct crypto_async_request *req, int err)
         complete(&res->completion);
 }
 
+static int testmgr_alloc_buf(char *buf[XBUFSIZE])
+{
+        int i;
+
+        for (i = 0; i < XBUFSIZE; i++) {
+                buf[i] = (void *)__get_free_page(GFP_KERNEL);
+                if (!buf[i])
+                        goto err_free_buf;
+        }
+
+        return 0;
+
+err_free_buf:
+        while (i-- > 0)
+                free_page((unsigned long)buf[i]);
+
+        return -ENOMEM;
+}
+
+static void testmgr_free_buf(char *buf[XBUFSIZE])
+{
+        int i;
+
+        for (i = 0; i < XBUFSIZE; i++)
+                free_page((unsigned long)buf[i]);
+}
+
 static int test_hash(struct crypto_ahash *tfm, struct hash_testvec *template,
                      unsigned int tcount)
 {
@@ -137,8 +161,12 @@ static int test_hash(struct crypto_ahash *tfm, struct hash_testvec *template,
         char result[64];
         struct ahash_request *req;
         struct tcrypt_result tresult;
-        int ret;
         void *hash_buff;
+        char *xbuf[XBUFSIZE];
+        int ret = -ENOMEM;
+
+        if (testmgr_alloc_buf(xbuf))
+                goto out_nobuf;
 
         init_completion(&tresult.completion);
 
@@ -146,7 +174,6 @@ static int test_hash(struct crypto_ahash *tfm, struct hash_testvec *template,
         if (!req) {
                 printk(KERN_ERR "alg: hash: Failed to allocate request for "
                        "%s\n", algo);
-                ret = -ENOMEM;
                 goto out_noreq;
         }
         ahash_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,
@@ -272,6 +299,8 @@ static int test_hash(struct crypto_ahash *tfm, struct hash_testvec *template,
 out:
         ahash_request_free(req);
 out_noreq:
+        testmgr_free_buf(xbuf);
+out_nobuf:
         return ret;
 }
 
@@ -280,7 +309,7 @@ static int test_aead(struct crypto_aead *tfm, int enc,
 {
         const char *algo = crypto_tfm_alg_driver_name(crypto_aead_tfm(tfm));
         unsigned int i, j, k, n, temp;
-        int ret = 0;
+        int ret = -ENOMEM;
         char *q;
         char *key;
         struct aead_request *req;
@@ -292,6 +321,13 @@ static int test_aead(struct crypto_aead *tfm, int enc,
         void *input;
         void *assoc;
         char iv[MAX_IVLEN];
+        char *xbuf[XBUFSIZE];
+        char *axbuf[XBUFSIZE];
+
+        if (testmgr_alloc_buf(xbuf))
+                goto out_noxbuf;
+        if (testmgr_alloc_buf(axbuf))
+                goto out_noaxbuf;
 
         if (enc == ENCRYPT)
                 e = "encryption";
@@ -304,7 +340,6 @@ static int test_aead(struct crypto_aead *tfm, int enc,
         if (!req) {
                 printk(KERN_ERR "alg: aead: Failed to allocate request for "
                        "%s\n", algo);
-                ret = -ENOMEM;
                 goto out;
         }
 
@@ -581,6 +616,10 @@ static int test_aead(struct crypto_aead *tfm, int enc,
 
 out:
         aead_request_free(req);
+        testmgr_free_buf(axbuf);
+out_noaxbuf:
+        testmgr_free_buf(xbuf);
+out_noxbuf:
         return ret;
 }
 
@@ -589,10 +628,14 @@ static int test_cipher(struct crypto_cipher *tfm, int enc,
 {
         const char *algo = crypto_tfm_alg_driver_name(crypto_cipher_tfm(tfm));
         unsigned int i, j, k;
-        int ret;
         char *q;
         const char *e;
         void *data;
+        char *xbuf[XBUFSIZE];
+        int ret = -ENOMEM;
+
+        if (testmgr_alloc_buf(xbuf))
+                goto out_nobuf;
 
         if (enc == ENCRYPT)
                 e = "encryption";
@@ -646,6 +689,8 @@ static int test_cipher(struct crypto_cipher *tfm, int enc,
         ret = 0;
 
 out:
+        testmgr_free_buf(xbuf);
+out_nobuf:
         return ret;
 }
 
@@ -655,7 +700,6 @@ static int test_skcipher(struct crypto_ablkcipher *tfm, int enc,
         const char *algo =
                 crypto_tfm_alg_driver_name(crypto_ablkcipher_tfm(tfm));
         unsigned int i, j, k, n, temp;
-        int ret;
         char *q;
         struct ablkcipher_request *req;
         struct scatterlist sg[8];
@@ -663,6 +707,11 @@ static int test_skcipher(struct crypto_ablkcipher *tfm, int enc,
         struct tcrypt_result result;
         void *data;
         char iv[MAX_IVLEN];
+        char *xbuf[XBUFSIZE];
+        int ret = -ENOMEM;
+
+        if (testmgr_alloc_buf(xbuf))
+                goto out_nobuf;
 
         if (enc == ENCRYPT)
                 e = "encryption";
@@ -675,7 +724,6 @@ static int test_skcipher(struct crypto_ablkcipher *tfm, int enc,
         if (!req) {
                 printk(KERN_ERR "alg: skcipher: Failed to allocate request "
                        "for %s\n", algo);
-                ret = -ENOMEM;
                 goto out;
         }
 
@@ -860,6 +908,8 @@ static int test_skcipher(struct crypto_ablkcipher *tfm, int enc,
 
 out:
         ablkcipher_request_free(req);
+        testmgr_free_buf(xbuf);
+out_nobuf:
         return ret;
 }
 
@@ -2245,41 +2295,3 @@ notest:
         return 0;
 }
 EXPORT_SYMBOL_GPL(alg_test);
-
-int __init testmgr_init(void)
-{
-        int i;
-
-        for (i = 0; i < XBUFSIZE; i++) {
-                xbuf[i] = (void *)__get_free_page(GFP_KERNEL);
-                if (!xbuf[i])
-                        goto err_free_xbuf;
-        }
-
-        for (i = 0; i < XBUFSIZE; i++) {
-                axbuf[i] = (void *)__get_free_page(GFP_KERNEL);
-                if (!axbuf[i])
-                        goto err_free_axbuf;
-        }
-
-        return 0;
-
-err_free_axbuf:
-        for (i = 0; i < XBUFSIZE && axbuf[i]; i++)
-                free_page((unsigned long)axbuf[i]);
-err_free_xbuf:
-        for (i = 0; i < XBUFSIZE && xbuf[i]; i++)
-                free_page((unsigned long)xbuf[i]);
-
-        return -ENOMEM;
-}
-
-void testmgr_exit(void)
-{
-        int i;
-
-        for (i = 0; i < XBUFSIZE; i++)
-                free_page((unsigned long)axbuf[i]);
-        for (i = 0; i < XBUFSIZE; i++)
-                free_page((unsigned long)xbuf[i]);
-}