Re: [PATCH] block: NULL dereference on error path in __blkdev_get()

From: Justin TerAvest
Date: Fri Mar 18 2011 - 18:27:33 EST


On Fri, Mar 18, 2011 at 1:37 AM, Tejun Heo <tj@xxxxxxxxxx> wrote:
> From: Dan Carpenter <error27@xxxxxxxxx>
>
> "disk" is always NULL when we goto out.  There was a check for this
> before, but it was removed in 69e02c59a7d9 "block: Don't check events
> while open is in progress".
>
> Signed-off-by: Dan Carpenter <error27@xxxxxxxxx>
> Acked-by: Tejun Heo <tj@xxxxxxxxxx>

I was running into this problem too; this patch fixes the problem.

Tested-by: Justin TerAvest <teravest@xxxxxxxxxx>

>
> diff --git a/fs/block_dev.c b/fs/block_dev.c
> index fbe05cb..7d02afb 100644
> --- a/fs/block_dev.c
> +++ b/fs/block_dev.c
> @@ -1181,9 +1181,9 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part)
>  out_unlock_bdev:
>        mutex_unlock(&bdev->bd_mutex);
>        disk_unblock_events(disk);
> - out:
>        module_put(disk->fops->owner);
>        put_disk(disk);
> + out:
>        bdput(bdev);
>
>        return ret;
> --
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