[CRYPTO] tcrypt: Catch cipher destination memory corruption

Check whether the destination buffer is written to beyond the last
byte contained in the scatterlist.

Also change IDX1 of the cross-page access offsets to a multiple of 4.
This triggers a corruption in the HIFN driver and doesn't seem to
negatively impact other testcases.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/crypto/tcrypt.c b/crypto/tcrypt.c
index 285c093abb7295276a5eff4bb450af85aae8e2dd..69eb29e1a53ba23c480b8b4ca523263437c9c1f9 100644 (file)
--- a/crypto/tcrypt.c
+++ b/crypto/tcrypt.c
@@ -39,7 +39,7 @@
 /*
  * Indexes into the xbuf to simulate cross-page access.
  */
-#define IDX1           37
+#define IDX1           32
 #define IDX2           32400
 #define IDX3           1
 #define IDX4           8193
@@ -211,7 +211,7 @@ out:
 static void test_aead(char *algo, int enc, struct aead_testvec *template,
                      unsigned int tcount)
 {
-       unsigned int ret, i, j, k, temp;
+       unsigned int ret, i, j, k, n, temp;
        char *q;
        struct crypto_aead *tfm;
        char *key;
@@ -353,7 +353,6 @@ next_one:
        }
 
        printk(KERN_INFO "\ntesting %s %s across pages (chunking)\n", algo, e);
-       memset(xbuf, 0, XBUFSIZE);
        memset(axbuf, 0, XBUFSIZE);
 
        for (i = 0, j = 0; i < tcount; i++) {
@@ -381,6 +380,7 @@ next_one:
                                        goto out;
                        }
 
+                       memset(xbuf, 0, XBUFSIZE);
                        sg_init_table(sg, template[i].np);
                        for (k = 0, temp = 0; k < template[i].np; k++) {
                                memcpy(&xbuf[IDX[k]],
@@ -452,6 +452,14 @@ next_one:
                                               0 : authsize)) ?
                                       "fail" : "pass");
 
+                               for (n = 0; q[template[i].tap[k] + n]; n++)
+                                       ;
+                               if (n) {
+                                       printk("Result buffer corruption %u "
+                                              "bytes:\n", n);
+                                       hexdump(&q[template[i].tap[k]], n);
+                               }
+
                                temp += template[i].tap[k];
                                kunmap(sg_page(&sg[k]));
                        }
@@ -466,7 +474,7 @@ out:
 static void test_cipher(char *algo, int enc,
                        struct cipher_testvec *template, unsigned int tcount)
 {
-       unsigned int ret, i, j, k, temp;
+       unsigned int ret, i, j, k, n, temp;
        char *q;
        struct crypto_ablkcipher *tfm;
        struct ablkcipher_request *req;
@@ -574,7 +582,6 @@ static void test_cipher(char *algo, int enc,
        }
 
        printk("\ntesting %s %s across pages (chunking)\n", algo, e);
-       memset(xbuf, 0, XBUFSIZE);
 
        j = 0;
        for (i = 0; i < tcount; i++) {
@@ -589,6 +596,7 @@ static void test_cipher(char *algo, int enc,
                        printk("test %u (%d bit key):\n",
                        j, template[i].klen * 8);
 
+                       memset(xbuf, 0, XBUFSIZE);
                        crypto_ablkcipher_clear_flags(tfm, ~0);
                        if (template[i].wk)
                                crypto_ablkcipher_set_flags(
@@ -648,6 +656,14 @@ static void test_cipher(char *algo, int enc,
                                        memcmp(q, template[i].result + temp,
                                                template[i].tap[k]) ? "fail" :
                                        "pass");
+
+                               for (n = 0; q[template[i].tap[k] + n]; n++)
+                                       ;
+                               if (n) {
+                                       printk("Result buffer corruption %u "
+                                              "bytes:\n", n);
+                                       hexdump(&q[template[i].tap[k]], n);
+                               }
                                temp += template[i].tap[k];
                                kunmap(sg_page(&sg[k]));
                        }