On 01/11/2018 10:57 AM, David Miller wrote: > From: Wei Yongjun <weiyongjun1@xxxxxxxxxx> > Date: Thu, 11 Jan 2018 11:21:51 +0000 > >> platform_get_resource() may fail and return NULL, so we should >> better check it's return value to avoid a NULL pointer dereference >> a bit later in the code. >> >> This is detected by Coccinelle semantic patch. >> >> @@ >> expression pdev, res, n, t, e, e1, e2; >> @@ >> >> res = platform_get_resource(pdev, t, n); >> + if (!res) >> + return -EINVAL; >> ... when != res == NULL >> e = devm_ioremap(e1, res->start, e2); >> >> Signed-off-by: Wei Yongjun <weiyongjun1@xxxxxxxxxx> > > Applied, thank you. Sorry, being really lagging behind lately: Reviewed-by: Florian Fainelli <f.fainelli@xxxxxxxxx> > >> diff --git a/drivers/net/phy/mdio-bcm-unimac.c b/drivers/net/phy/mdio-bcm-unimac.c >> index 08e0647..8d37066 100644 >> --- a/drivers/net/phy/mdio-bcm-unimac.c >> +++ b/drivers/net/phy/mdio-bcm-unimac.c >> @@ -205,6 +205,8 @@ static int unimac_mdio_probe(struct platform_device *pdev) >> return -ENOMEM; >> >> r = platform_get_resource(pdev, IORESOURCE_MEM, 0); >> + if (!r) >> + return -EINVAL; >> >> /* Just ioremap, as this MDIO block is usually integrated into an >> * Ethernet MAC controller register range >> > > I have to say, the devm_*() routines may make it easier to write drivers and probe > routines, but it makes patches much harder to review. > > I couldn't figure out if you were leaking resources here without going into the > source file and looking at all of the relevant context. > > Just though I'd make this meta-comment... Agreed, what appears to be worse is that the kitchen sync routine like devm_ioremap_resource() properly protects against NULL resource pointer whereas simpler routines like devm_ioremap() do not because it usually is called from a caller that did the check for us. Thanks Wei! -- Florian -- To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
