Hi Artem,
On 07/19/2016 07:30 AM, Artem Savkov wrote:
> When bl_parse_deviceid() fails in bl_alloc_deviceid_node() on
> blkdev_get_by_*() step we get an pnfs_block_dev struct that is
> uninitialized except for bdev field which is set to whatever error
> blkdev_get_by_*() returns. bl_free_device() then tries to call
> blkdev_put() if bdev is not 0 resulting in a wrong pointer dereference.
>
> Fixing this by making sure bdev is not an error code in bl_free_device().
>
> Signed-off-by: Artem Savkov <asav...@redhat.com>
> ---
> fs/nfs/blocklayout/dev.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/fs/nfs/blocklayout/dev.c b/fs/nfs/blocklayout/dev.c
> index 118252f..7db3af0 100644
> --- a/fs/nfs/blocklayout/dev.c
> +++ b/fs/nfs/blocklayout/dev.c
> @@ -33,7 +33,7 @@ bl_free_device(struct pnfs_block_dev *dev)
> pr_err("failed to unregister PR key.\n");
> }
>
> - if (dev->bdev)
> + if (dev->bdev && !IS_ERR(dev->bdev))
This looks pretty straightforward, but can you use IS_ERR_OR_NULL() instead?
It accomplishes the same check with slightly cleaner code :)
Thanks,
Anna
> blkdev_put(dev->bdev, FMODE_READ | FMODE_WRITE);
> }
> }
>
