linux-kernel - [PATCH v2 0/2] pci: endpoint: Fix double free in pci_epf

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Message-Id: <20180226171617.10016-1-embedded24@evers-fischer.de>
Date:   Mon, 26 Feb 2018 18:16:15 +0100
From:   Rolf Evers-Fischer <embedded24@...rs-fischer.de>
To:     kishon@...com
Cc:     lorenzo.pieralisi@....com, bhelgaas@...gle.com,
        linux-pci@...r.kernel.org, linux-kernel@...r.kernel.org,
        andy.shevchenko@...il.com,
        Rolf Evers-Fischer <embedded24@...rs-fischer.de>
Subject: [PATCH v2 0/2] pci: endpoint: Fix double free in pci_epf_create()

This is version 2 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 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()

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

-- 
2.16.2