Re: [PATCH v2] mtd: nand: vf610: fix error handling in vf610_nfc_probe()

From: Boris Brezillon
Date: Sat Jan 06 2018 - 04:26:02 EST


On Sat, 23 Dec 2017 22:18:26 +0300
Alexey Khoroshilov <khoroshilov@xxxxxxxxx> wrote:

> vf610_nfc_probe() misses error handling of mtd_device_register().
>
> Found by Linux Driver Verification project (linuxtesting.org).
>
> Signed-off-by: Alexey Khoroshilov <khoroshilov@xxxxxxxxx>
> ---
> v2: Add nand_cleanup() to undone nand_scan_tail() as Boris Brezillon noted.
>
> drivers/mtd/nand/vf610_nfc.c | 25 +++++++++++++++----------
> 1 file changed, 15 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/mtd/nand/vf610_nfc.c b/drivers/mtd/nand/vf610_nfc.c
> index 8037d4b48a05..2dac25a8ccbf 100644
> --- a/drivers/mtd/nand/vf610_nfc.c
> +++ b/drivers/mtd/nand/vf610_nfc.c
> @@ -682,7 +682,7 @@ static int vf610_nfc_probe(struct platform_device *pdev)
> dev_err(nfc->dev,
> "Only one NAND chip supported!\n");
> err = -EINVAL;
> - goto error;
> + goto err_node;
> }
>
> nand_set_flash_node(chip, child);
> @@ -712,7 +712,7 @@ static int vf610_nfc_probe(struct platform_device *pdev)
> err = devm_request_irq(nfc->dev, irq, vf610_nfc_irq, 0, DRV_NAME, mtd);
> if (err) {
> dev_err(nfc->dev, "Error requesting IRQ!\n");
> - goto error;
> + goto err_node;
> }
>
> vf610_nfc_preinit_controller(nfc);
> @@ -720,7 +720,7 @@ static int vf610_nfc_probe(struct platform_device *pdev)
> /* first scan to find the device and get the page size */
> err = nand_scan_ident(mtd, 1, NULL);
> if (err)
> - goto error;
> + goto err_node;
>
> vf610_nfc_init_controller(nfc);
>
> @@ -732,20 +732,20 @@ static int vf610_nfc_probe(struct platform_device *pdev)
> if (mtd->writesize + mtd->oobsize > PAGE_2K + OOB_MAX - 8) {
> dev_err(nfc->dev, "Unsupported flash page size\n");
> err = -ENXIO;
> - goto error;
> + goto err_node;
> }
>
> if (chip->ecc.mode == NAND_ECC_HW) {
> if (mtd->writesize != PAGE_2K && mtd->oobsize < 64) {
> dev_err(nfc->dev, "Unsupported flash with hwecc\n");
> err = -ENXIO;
> - goto error;
> + goto err_node;
> }
>
> if (chip->ecc.size != mtd->writesize) {
> dev_err(nfc->dev, "Step size needs to be page size\n");
> err = -ENXIO;
> - goto error;
> + goto err_node;
> }
>
> /* Only 64 byte ECC layouts known */
> @@ -765,7 +765,7 @@ static int vf610_nfc_probe(struct platform_device *pdev)
> } else {
> dev_err(nfc->dev, "Unsupported ECC strength\n");
> err = -ENXIO;
> - goto error;
> + goto err_node;
> }
>
> chip->ecc.read_page = vf610_nfc_read_page;
> @@ -777,14 +777,19 @@ static int vf610_nfc_probe(struct platform_device *pdev)
> /* second phase scan */
> err = nand_scan_tail(mtd);
> if (err)
> - goto error;
> + goto err_node;
>
> platform_set_drvdata(pdev, mtd);
>
> /* Register device in MTD */
> - return mtd_device_register(mtd, NULL, 0);
> + err = mtd_device_register(mtd, NULL, 0);
> + if (err)
> + goto err_nand;
> + return 0;
>
> -error:
> +err_nand:
> + nand_cleanup(chip);
> +err_node:
> of_node_put(nand_get_flash_node(chip));

I also realize calling of_node_put() here is wrong because nothing in
this code retains a reference to the DT node.

> err_clk:
> clk_disable_unprepare(nfc->clk);