lkml.org 
[lkml]   [2013]   [Nov]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [Xen-devel] [PATCH] block: xen-blkfront: Fix possible NULL ptr dereference
On 09/11/13 16:36, Felipe Pena wrote:
> In the blkif_release function the bdget_disk() call might returns
> a NULL ptr which might be dereferenced on bdev->bd_openers checking
>
> Signed-off-by: Felipe Pena <felipensp@gmail.com>
> ---
> drivers/block/xen-blkfront.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
> index a4660bb..7bb1552 100644
> --- a/drivers/block/xen-blkfront.c
> +++ b/drivers/block/xen-blkfront.c
> @@ -1959,6 +1959,9 @@ static void blkif_release(struct gendisk *disk, fmode_t mode)
>
> bdev = bdget_disk(disk, 0);
>
> + if (!bdev)
> + goto out_mutex;

Is this actually possible? By looking at blkfront code, it seems like we
don't remove the device if it is still open, so maybe this should be a
BUG_ON instead of failing silently.

Roger.


\
 
 \ /
  Last update: 2013-11-11 11:21    [W:0.293 / U:0.076 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site