Re: [PATCH] mm/gup: Use put_user_page*() instead of put_page*()

[Jens Axboe]

On 7/14/19 1:08 PM, Bharath Vedartham wrote:
> diff --git a/fs/io_uring.c b/fs/io_uring.c
> index 4ef62a4..b4a4549 100644
> --- a/fs/io_uring.c
> +++ b/fs/io_uring.c
> @@ -2694,10 +2694,9 @@ static int io_sqe_buffer_register(struct io_ring_ctx *ctx, void __user *arg,
>   			 * if we did partial map, or found file backed vmas,
>   			 * release any pages we did get
>   			 */
> -			if (pret > 0) {
> -				for (j = 0; j < pret; j++)
> -					put_page(pages[j]);
> -			}
> +			if (pret > 0)
> +				put_user_pages(pages, pret);
> +
>   			if (ctx->account_mem)
>   				io_unaccount_mem(ctx->user, nr_pages);
>   			kvfree(imu->bvec);

You handled just the failure case of the buffer registration, but not
the actual free in io_sqe_buffer_unregister().

-- 
Jens Axboe