Commit 7d92df69 authored Jan 08, 2010 by Anna Lemehova Committed by Linus Torvalds Jan 11, 2010

mmc_block: add dev_t initialization check



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>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 0a884223

drivers/mmc/card/block.c

+5 −0

Original line number	Diff line number	Diff line
		@@ -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);

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