Re: [PATCH] PCI: rockchip-dwc: Potential error pointer dereference in probe
From: Rob Herring <robh@kernel.org>
Date: 2021-08-13 15:59:59
Also in:
kernel-janitors, linux-pci, linux-rockchip
On Fri, Aug 13, 2021 at 8:47 AM Robin Murphy [off-list ref] wrote:
On 2021-08-13 14:34, Rob Herring wrote:quoted
On Fri, Aug 13, 2021 at 7:55 AM Robin Murphy [off-list ref] wrote:quoted
On 2021-08-13 12:33, Dan Carpenter wrote:quoted
If devm_regulator_get_optional() returns an error pointer, then we should return it to the user. The current code makes an exception for -ENODEV that will result in an error pointer dereference on the next line when it calls regulator_enable(). Remove the exception.Doesn't this break the apparent intent of the regulator being optional, though?I'm pretty sure 'optional' means ENODEV is never returned. So there wasn't any real problem, but the check was unnecessary.In fact it's the other way round - "optional" in this case is for when the supply may legitimately not exist so the driver may or may not need to handle it, so it can return -ENODEV if a regulator isn't described by firmware. A non-optional regulator is assumed to represent a necessary supply, so if there's nothing described by firmware you get the (valid) dummy regulator back.
Ah yes, regulators is the oddball. Surely no one else will assume the same behavior of _optional() variants across subsystems... ;) _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel