Re: [PATCH 0/2] mmc: core: null pointer dereference bug

From: Ulf Hansson
Date: Thu Mar 16 2017 - 10:47:02 EST


On 15 March 2017 at 09:48, Tobin C. Harding <me@xxxxxxxx> wrote:
> Various functions take as parameter an optional pointer. Pointer
> should be guarded with non-NULL check before dereferencing.
>
> While fixing this bug it was found that the file contains multiple
> functions doing variations on the same thing, sdio_readb(),
> sdio_writeb(), sdio_readw(), sdio_writew() etc. Although the functions
> have very similar logic the code is laid out in a variety of
> ways. This makes it overly complicated to read. There is a already a
> nice clean chunk of code, if we use this format for all instances then
> we will have cleaned up the code, reduced the line count and lessened
> the cognitive load required while reading.
>
> Patch 01 adds non-NULL check before dereference of pointer.
>
> Patch 02 cleans up the return code to be simple and uniform.
>
> Code has not been tested. sdio_io.c with patches applied has been
> checked with checkpatch, Sparse, and Smatch. Each patch has been
> applied and built on x86_64 and PowerPC
>
> Tobin C. Harding (2):
> mmc: core: guard dereference of optional parameter
> mmc: core: simplify return code
>
> drivers/mmc/core/sdio_io.c | 54 ++++++++++++++++++----------------------------
> 1 file changed, 21 insertions(+), 33 deletions(-)
>
> --
> 2.7.4
>

Thanks, applied for next!

Kind regards
Uffe