mmc: sdio: Fix several potential memory leaks in mmc_sdio_init_card()

Over the years, the code in mmc_sdio_init_card() has grown to become quite
messy. Unfortunate this has also lead to that several paths are leaking
memory in form of an allocated struct mmc_card, which includes additional
data, such as initialized struct device for example.

Unfortunate, it's a too complex task find each offending commit. Therefore,
this change fixes all memory leaks at once.

Cc: <stable@vger.kernel.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Link: https://lore.kernel.org/r/20200430091640.455-3-ulf.hansson@linaro.org

drivers/mmc/core/sdio.c

@@ -584,7 +584,7 @@ static int mmc_sdio_init_card(struct mmc_host *host, u32 ocr,
 	 */
 	err = mmc_send_io_op_cond(host, ocr, &rocr);
 	if (err)
-		goto err;
+		return err;
 
 	/*
 	 * For SPI, enable CRC as appropriate.
@@ -592,17 +592,15 @@ static int mmc_sdio_init_card(struct mmc_host *host, u32 ocr,
 	if (mmc_host_is_spi(host)) {
 		err = mmc_spi_set_crc(host, use_spi_crc);
 		if (err)
-			goto err;
+			return err;
 	}
 
 	/*
 	 * Allocate card structure.
 	 */
 	card = mmc_alloc_card(host, NULL);
-	if (IS_ERR(card)) {
-		err = PTR_ERR(card);
-		goto err;
-	}
+	if (IS_ERR(card))
+		return PTR_ERR(card);
 
 	if ((rocr & R4_MEMORY_PRESENT) &&
 	    mmc_sd_get_cid(host, ocr & rocr, card->raw_cid, NULL) == 0) {
@@ -610,19 +608,15 @@ static int mmc_sdio_init_card(struct mmc_host *host, u32 ocr,
 
 		if (oldcard && (oldcard->type != MMC_TYPE_SD_COMBO ||
 		    memcmp(card->raw_cid, oldcard->raw_cid, sizeof(card->raw_cid)) != 0)) {
-			mmc_remove_card(card);
-			pr_debug("%s: Perhaps the card was replaced\n",
-				mmc_hostname(host));
-			return -ENOENT;
+			err = -ENOENT;
+			goto mismatch;
 		}
 	} else {
 		card->type = MMC_TYPE_SDIO;
 
 		if (oldcard && oldcard->type != MMC_TYPE_SDIO) {
-			mmc_remove_card(card);
-			pr_debug("%s: Perhaps the card was replaced\n",
-				mmc_hostname(host));
-			return -ENOENT;
+			err = -ENOENT;
+			goto mismatch;
 		}
 	}
 
@@ -677,7 +671,7 @@ static int mmc_sdio_init_card(struct mmc_host *host, u32 ocr,
 	if (!oldcard && card->type == MMC_TYPE_SD_COMBO) {
 		err = mmc_sd_get_csd(host, card);
 		if (err)
-			return err;
+			goto remove;
 
 		mmc_decode_cid(card);
 	}
@@ -704,7 +698,12 @@ static int mmc_sdio_init_card(struct mmc_host *host, u32 ocr,
 			mmc_set_timing(card->host, MMC_TIMING_SD_HS);
 		}
 
-		goto finish;
+		if (oldcard)
+			mmc_remove_card(card);
+		else
+			host->card = card;
+
+		return 0;
 	}
 
 	/*
@@ -730,16 +729,14 @@ static int mmc_sdio_init_card(struct mmc_host *host, u32 ocr,
 		goto remove;
 
 	if (oldcard) {
-		int same = (card->cis.vendor == oldcard->cis.vendor &&
-			    card->cis.device == oldcard->cis.device);
+		if (card->cis.vendor == oldcard->cis.vendor &&
+		    card->cis.device == oldcard->cis.device) {
 			mmc_remove_card(card);
-		if (!same) {
-			pr_debug("%s: Perhaps the card was replaced\n",
-				mmc_hostname(host));
-			return -ENOENT;
-		}
-
 			card = oldcard;
+		} else {
+			err = -ENOENT;
+			goto mismatch;
+		}
 	}
 	card->ocr = ocr_card;
 	mmc_fixup_device(card, sdio_fixup_methods);
@@ -800,16 +797,15 @@ static int mmc_sdio_init_card(struct mmc_host *host, u32 ocr,
 		err = -EINVAL;
 		goto remove;
 	}
-finish:
-	if (!oldcard)
+
 	host->card = card;
 	return 0;
 
+mismatch:
+	pr_debug("%s: Perhaps the card was replaced\n", mmc_hostname(host));
 remove:
-	if (!oldcard)
+	if (oldcard != card)
 		mmc_remove_card(card);
-
-err:
 	return err;
 }