Patch "xen/blkback: fix reference counting" has been added to the 3.4-stable tree

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



This is a note to let you know that I've just added the patch titled

    xen/blkback: fix reference counting

to the 3.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     xen-blkback-fix-reference-counting.patch
and it can be found in the queue-3.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.


>From ea5ec76d76da9279d12027c1828544c5ccbe7932 Mon Sep 17 00:00:00 2001
From: Vegard Nossum <vegard.nossum@xxxxxxxxxx>
Date: Thu, 5 Sep 2013 13:00:14 +0200
Subject: xen/blkback: fix reference counting

From: Vegard Nossum <vegard.nossum@xxxxxxxxxx>

commit ea5ec76d76da9279d12027c1828544c5ccbe7932 upstream.

If the permission check fails, we drop a reference to the blkif without
having taken it in the first place. The bug was introduced in commit
604c499cbbcc3d5fe5fb8d53306aa0fae1990109 (xen/blkback: Check device
permissions before allowing OP_DISCARD).

Cc: Jan Beulich <JBeulich@xxxxxxxx>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
Signed-off-by: Vegard Nossum <vegard.nossum@xxxxxxxxxx>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/block/xen-blkback/blkback.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/drivers/block/xen-blkback/blkback.c
+++ b/drivers/block/xen-blkback/blkback.c
@@ -401,6 +401,8 @@ static int dispatch_discard_io(struct xe
 	unsigned long secure;
 	struct phys_req preq;
 
+	xen_blkif_get(blkif);
+
 	preq.sector_number = req->u.discard.sector_number;
 	preq.nr_sects      = req->u.discard.nr_sectors;
 
@@ -413,7 +415,6 @@ static int dispatch_discard_io(struct xe
 	}
 	blkif->st_ds_req++;
 
-	xen_blkif_get(blkif);
 	secure = (blkif->vbd.discard_secure &&
 		 (req->u.discard.flag & BLKIF_DISCARD_SECURE)) ?
 		 BLKDEV_DISCARD_SECURE : 0;


Patches currently in stable-queue which might be from vegard.nossum@xxxxxxxxxx are

queue-3.4/xen-blkback-fix-reference-counting.patch
--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html




[Index of Archives]     [Linux Kernel]     [Kernel Development Newbies]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite Hiking]     [Linux Kernel]     [Linux SCSI]