Messages in this thread | | | Subject | Re: [PATCH v2 2/2] mtd: nand: atmel_nand: fix a possible NULL dereference | From | Josh Wu <> | Date | Wed, 25 Nov 2015 10:20:02 +0800 |
| |
Hi, Corentin
On 11/24/2015 9:12 PM, LABBE Corentin wrote: > On Fri, Nov 20, 2015 at 04:33:14PM +0800, Josh Wu wrote: >> Hi, Corentin >> >> Thanks for the patch. It looks fine to me, just one nitpick in below: >> >> On 11/20/2015 3:45 PM, LABBE Corentin wrote: >>> of_match_device could return NULL, and so cause a NULL pointer >>> dereference later. >>> >>> Signed-off-by: LABBE Corentin <clabbe.montjoie@gmail.com> >>> --- >>> drivers/mtd/nand/atmel_nand.c | 5 +++-- >>> 1 file changed, 3 insertions(+), 2 deletions(-) >>> >>> diff --git a/drivers/mtd/nand/atmel_nand.c b/drivers/mtd/nand/atmel_nand.c >>> index 475c938..7902967 100644 >>> --- a/drivers/mtd/nand/atmel_nand.c >>> +++ b/drivers/mtd/nand/atmel_nand.c >>> @@ -1496,8 +1496,9 @@ static int atmel_of_init_port(struct atmel_nand_host *host, >>> struct atmel_nand_data *board = &host->board; >>> enum of_gpio_flags flags = 0; >>> >>> - host->caps = (struct atmel_nand_caps *) >>> - of_match_device(atmel_nand_dt_ids, host->dev)->data; >>> + host->caps = of_device_get_match_data(host->dev); >>> + if (!host->caps) >>> + return 1; >> it's better to use -EINVAL here. >> > Hello > > I do that Uwe Kleine-König said to me to do in others thread: > https://lkml.org/lkml/2015/11/12/70 and https://lkml.org/lkml/2015/11/16/211
Thank you for the information. I checked the imx serial driver(drivers/tty/serial/imx.c) in serial_imx_probe():
... ret = serial_imx_probe_dt(sport, pdev); if (ret > 0) ---> So here is why you need to return 1 in serial_imx_probe_dt(). serial_imx_probe_pdata(sport, pdev); else if (ret < 0) return ret;
There has a branch to check whether ret is > 0 or < 0. So that's why you need to return 1 in imx serial driver.
But in atmel_nand driver, we don't have such code for that. The atmel_of_init_port() is only used for dt probe. So if dt is not matched, just return an error.
> > Regards > Best Regards, Josh Wu
| |