[PATCH 26/52] mmc_block: add dev_t initialization check

Greg Kroah-Hartman
2010-01-14T22:28:40Z

From: Anna Lemehova <EXT-Anna.Lemehova@nokia.com>

commit 7d92df692994472cab6045bbd9d0e2c4afa4365f upstream.

When a card is removed before mmc_blk_probe() has called add_disk(), then
the minor field is uninitialized and has value 0. This caused
mmc_blk_put() to always release devidx 0 even if 0 was still in use. Then
the next mmc_blk_probe() used the first free idx of 0, which oopses in
sysfs, since it is used by another card.

Signed-off-by: Anna Lemehova <EXT-Anna.Lemehova@nokia.com>
Signed-off-by: Adrian Hunter <adrian.hunter@nokia.com>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
drivers/mmc/card/block.c | 5 +++++
1 files changed, 5 insertions(+), 0 deletions(-)

diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
index 85f0e8c..5988573 100644
--- a/drivers/mmc/card/block.c
+++ b/drivers/mmc/card/block.c
@@ -85,7 +85,12 @@ static void mmc_blk_put(struct mmc_blk_data *md)
mutex_lock(&open_lock);
md->usage--;
if (md->usage == 0) {
+ int devmaj = MAJOR(disk_devt(md->disk));
int devidx = MINOR(disk_devt(md->disk)) >> MMC_SHIFT;
+
+ if (!devmaj)
+ devidx = md->disk->first_minor >> MMC_SHIFT;
+
__clear_bit(devidx, dev_use);

put_disk(md->disk);
--
1.6.6