kernel: mt29f_spinand: fix memory leak during page program

Memory is allocated with devm_kzalloc() on every page program
and leaks until device is closed (which never happens).

Convert to kzalloc() and handle error paths manually.

Signed-off-by: Mantas Pucka <mantas@8devices.com>

target/linux/generic/hack-4.14/400-mt29f_spinand-fix-memleak.patch

@@ -0,0 +1,90 @@
+--- a/drivers/staging/mt29f_spinand/mt29f_spinand.c
++++ b/drivers/staging/mt29f_spinand/mt29f_spinand.c
+@@ -492,7 +492,7 @@ static int spinand_program_page(struct s
+ #ifdef CONFIG_MTD_SPINAND_ONDIEECC
+ 	unsigned int i, j;
+ 
+-	wbuf = devm_kzalloc(&spi_nand->dev, CACHE_BUF, GFP_KERNEL);
++	wbuf = kzalloc(CACHE_BUF, GFP_KERNEL);
+ 	if (!wbuf)
+ 		return -ENOMEM;
+ 
+@@ -500,7 +500,7 @@ static int spinand_program_page(struct s
+ 	retval = spinand_read_page(spi_nand, page_id, 0, CACHE_BUF, wbuf);
+ 	if (retval < 0) {
+ 		dev_err(&spi_nand->dev, "ecc error on read page!!!\n");
+-		return retval;
++		goto cleanup;
+ 	}
+ 
+ 	for (i = offset, j = 0; i < len; i++, j++)
+@@ -510,7 +510,7 @@ static int spinand_program_page(struct s
+ 		retval = spinand_enable_ecc(spi_nand);
+ 		if (retval < 0) {
+ 			dev_err(&spi_nand->dev, "enable ecc failed!!\n");
+-			return retval;
++			goto cleanup;
+ 		}
+ 	}
+ #else
+@@ -519,7 +519,7 @@ static int spinand_program_page(struct s
+ 	retval = spinand_write_enable(spi_nand);
+ 	if (retval < 0) {
+ 		dev_err(&spi_nand->dev, "write enable failed!!\n");
+-		return retval;
++		goto cleanup;
+ 	}
+ 	if (wait_till_ready(spi_nand))
+ 		dev_err(&spi_nand->dev, "wait timedout!!!\n");
+@@ -527,23 +527,24 @@ static int spinand_program_page(struct s
+ 	retval = spinand_program_data_to_cache(spi_nand, page_id,
+ 					       offset, len, wbuf);
+ 	if (retval < 0)
+-		return retval;
++		goto cleanup;
+ 	retval = spinand_program_execute(spi_nand, page_id);
+ 	if (retval < 0)
+-		return retval;
++		goto cleanup;
+ 	while (1) {
+ 		retval = spinand_read_status(spi_nand, &status);
+ 		if (retval < 0) {
+ 			dev_err(&spi_nand->dev,
+ 				"error %d reading status register\n", retval);
+-			return retval;
++			goto cleanup;
+ 		}
+ 
+ 		if ((status & STATUS_OIP_MASK) == STATUS_READY) {
+ 			if ((status & STATUS_P_FAIL_MASK) == STATUS_P_FAIL) {
+ 				dev_err(&spi_nand->dev,
+ 					"program error, page %d\n", page_id);
+-				return -1;
++				retval = -1;
++				goto cleanup;
+ 			}
+ 			break;
+ 		}
+@@ -553,13 +554,20 @@ static int spinand_program_page(struct s
+ 		retval = spinand_disable_ecc(spi_nand);
+ 		if (retval < 0) {
+ 			dev_err(&spi_nand->dev, "disable ecc failed!!\n");
+-			return retval;
++			goto cleanup;
+ 		}
+ 		enable_hw_ecc = 0;
+ 	}
++	kfree(wbuf);
+ #endif
+-
+ 	return 0;
++
++cleanup:
++#ifdef CONFIG_MTD_SPINAND_ONDIEECC
++	kfree(wbuf);
++#endif
++	return retval;
++
+ }
+ 
+ /**