Re: [PATCH][next] io_uring: Fix memory leak on error return path.
From: Pavel Begunkov
Date: Thu Apr 29 2021 - 06:32:37 EST
On 4/29/21 11:26 AM, Colin King wrote:
> From: Colin Ian King <colin.king@xxxxxxxxxxxxx>
>
> Currently the -EINVAL error return path is leaking memory allocated
> to data. Fix this by kfree'ing data before the return.
>
> Addresses-Coverity: ("Resource leak")
> Fixes: c3a40789f6ba ("io_uring: allow empty slots for reg buffers")
> Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
> ---
> fs/io_uring.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/fs/io_uring.c b/fs/io_uring.c
> index 47c2f126f885..beeb477e4f6a 100644
> --- a/fs/io_uring.c
> +++ b/fs/io_uring.c
> @@ -8417,8 +8417,10 @@ static int io_sqe_buffers_register(struct io_ring_ctx *ctx, void __user *arg,
> ret = io_buffer_validate(&iov);
> if (ret)
> break;
> - if (!iov.iov_base && tag)
> + if (!iov.iov_base && tag) {> + kfree(data);
> return -EINVAL;
> + }
Buggy indeed, should have been:
ret = -EINVAL;
break;
Colin, can you resend with the change?
>
> ret = io_sqe_buffer_register(ctx, &iov, &ctx->user_bufs[i],
> &last_hpage);
>
--
Pavel Begunkov