[PATCH 4.0 051/220] mmc: tmio: Remove bogus un-initialization in tmio_mmc_host_free()

From: Greg Kroah-Hartman
Date: Sat May 02 2015 - 15:10:59 EST


4.0-stable review patch. If anyone has any objections, please let me know.

------------------

From: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>

commit 13a6a2ed1f5e77ae47c2b1a8e3bf22b2fa2d56ba upstream.

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>
Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/mmc/host/tmio_mmc_pio.c | 2 --
1 file changed, 2 deletions(-)

--- 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);



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