Re: [PATCH v3 0/2] pci: endpoint: Fix double free in pci_epf_create()

From: Lorenzo Pieralisi
Date: Tue Feb 27 2018 - 05:20:39 EST


On Tue, Feb 27, 2018 at 11:02:28AM +0100, Rolf Evers-Fischer wrote:
> This is version 3 of a patchset to avoid double free in function
> 'pci_epf_create()'.
>
> When I accidentally created a new endpoint device with an empty name,
> the kernel warned about "attempted to be registered with empty name!"
> and crashed afterwards.
>
> It turned out that the crash was not caused by the 'device_add()'
> function itself, but by a double kfree of 'epf->name' and 'epf'.
>
> The first patch just simplifies the code, while the second patch
> fixes the problem.
>
> Changes in v3:
> - Matched to other pending pci endpoint commits (thanks, Bjorn!)
> - Added "Fixes" tag in patch 2 (thanks, Andy!)
>
> Changes in v2:
> - Based on feedback from Lorenzo, Andy and Kishon (thanks!)
> - Change IDs removed
> - First patch completely reworked in order to eliminate the
> need for the second 'kstrdup' allocation and the 'kfree' of
> the first allocation.
> It was tested with name="pci_epf_test.0" and name="pci_epb":
> The 'epf->name' was "pci_epf_test" or "pci_epb" (=unchanged).
>
> Rolf Evers-Fischer (2):
> pci: endpoint: Simplify name allocation for epf device
> pci: endpoint: Fix kernel panic after put_device()
^^^

s/pci/PCI

Bjorn pointed that out too, I can do it when merging the patches myself
just a hint in case you have to respin it again, no problem.

Thanks,
Lorenzo

> drivers/pci/endpoint/pci-epf-core.c | 24 +++++-------------------
> 1 file changed, 5 insertions(+), 19 deletions(-)
>
> --
> 2.16.2
>