firmware_loader: Fix possible resource leak in fw_log_firmware_info()

The alg instance should be released under the exception path, otherwise
there may be resource leak here.

To mitigate this, free the alg instance with crypto_free_shash when kmalloc
fails.

Fixes: 02fe26f ("firmware_loader: Add debug message with checksum for FW file")
Signed-off-by: Gaosheng Cui <[email protected]>
Reviewed-by: Amadeusz Sławiński <[email protected]>
Reviewed-by: Russ Weight <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

Author: gscui

drivers/base/firmware_loader/main.c

@@ -829,19 +829,18 @@ static void fw_log_firmware_info(const struct firmware *fw, const char *name, st
 	shash->tfm = alg;
 
 	if (crypto_shash_digest(shash, fw->data, fw->size, sha256buf) < 0)
-		goto out_shash;
+		goto out_free;
 
 	for (int i = 0; i < SHA256_DIGEST_SIZE; i++)
 		sprintf(&outbuf[i * 2], "%02x", sha256buf[i]);
 	outbuf[SHA256_BLOCK_SIZE] = 0;
 	dev_dbg(device, "Loaded FW: %s, sha256: %s\n", name, outbuf);
 
-out_shash:
-	crypto_free_shash(alg);
 out_free:
 	kfree(shash);
 	kfree(outbuf);
 	kfree(sha256buf);
+	crypto_free_shash(alg);
 }
 #else
 static void fw_log_firmware_info(const struct firmware *fw, const char *name,