From: Andrew Morton <akpm@linux-foundation.org>
Date: Fri, 5 Sep 2008 21:00:24 +0000 (-0700)
Subject: drivers/mmc/card/block.c: fix refcount leak in mmc_block_open()
X-Git-Tag: v2.6.27-rc6~27
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=70bb08962ea9bd50797ae9f16b2493f5f7c65053;p=linux-2.6

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>
---

diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
index 86dbb36641..6986f39262 100644
--- a/drivers/mmc/card/block.c
+++ b/drivers/mmc/card/block.c
@@ -103,8 +103,10 @@ 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;