drivers/mmc/card/block.c: fix refcount leak in mmc_block_open()

mmc_block_open() increments md->usage although it returns with -EROFS when
default mounting a MMC/SD card with write protect switch on.  This
reference counting bug prevents /dev/mmcblkX from being released on card
removal, and situation worsen with reinsertion until the minor number
range runs out.

Reported-by: <sasin@solomon-systech.com>
Acked-by: Pierre Ossman <drzeus-list@drzeus.cx>
Cc: <stable@kernel.org>		[2.6.25.x, 2.6.26.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Andrew Morton 2008-09-05 14:00:24 -07:00 committed by Linus Torvalds
parent 22f30168d2
commit 70bb08962e

View file

@ -103,9 +103,11 @@ static int mmc_blk_open(struct inode *inode, struct file *filp)
check_disk_change(inode->i_bdev);
ret = 0;
if ((filp->f_mode & FMODE_WRITE) && md->read_only)
if ((filp->f_mode & FMODE_WRITE) && md->read_only) {
mmc_blk_put(md);
ret = -EROFS;
}
}
return ret;
}