Re: [PATCH] mmc: tmio: Remove bogus un-initialization in tmio_mmc_host_free()

From: Ulf Hansson
Date: Thu Mar 05 2015 - 08:41:20 EST


On 18 February 2015 at 17:34, Geert Uytterhoeven
<geert+renesas@xxxxxxxxx> wrote:
> If CONFIG_DEBUG_SLAB=y:
>
> sh_mobile_sdhi ee100000.sd: Got CD GPIO
> sh_mobile_sdhi ee100000.sd: Got WP GPIO
> platform ee100000.sd: Driver sh_mobile_sdhi requests probe deferral
> ...
> Slab corruption (Not tainted): kmalloc-1024 start=ed8b3c00, len=1024
> 2d0: 00 00 00 00 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b ....kkkkkkkkkkkk
> Prev obj: start=ed8b3800, len=1024
> 000: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
> 010: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
>
> Struct tmio_mmc_host is embedded inside struct mmc_host, and thus is
> freed by the call to mmc_free_host(). Hence it must not be written to
> afterwards, as that will corrupt freed (and perhaps already reused)
> memory.
>
> Fixes: 94b110aff8679b14 ("mmc: tmio: add tmio_mmc_host_alloc/free()")
> Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>

Applied, thanks!

Kind regards
Uffe

> ---
> drivers/mmc/host/tmio_mmc_pio.c | 2 --
> 1 file changed, 2 deletions(-)
>
> diff --git a/drivers/mmc/host/tmio_mmc_pio.c b/drivers/mmc/host/tmio_mmc_pio.c
> index a31c3573d386f8c6..dba7e1c19dd758e7 100644
> --- a/drivers/mmc/host/tmio_mmc_pio.c
> +++ b/drivers/mmc/host/tmio_mmc_pio.c
> @@ -1073,8 +1073,6 @@ EXPORT_SYMBOL(tmio_mmc_host_alloc);
> void tmio_mmc_host_free(struct tmio_mmc_host *host)
> {
> mmc_free_host(host->mmc);
> -
> - host->mmc = NULL;
> }
> EXPORT_SYMBOL(tmio_mmc_host_free);
>
> --
> 1.9.1
>
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