Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > linux.kernel > #1642888

Re: [PATCH 2/4] crypto: drbg wait for crypto op not signal safe

From Eric Biggers <ebiggers3@gmail.com>
Newsgroups linux.kernel
Subject Re: [PATCH 2/4] crypto: drbg wait for crypto op not signal safe
Date 2017-05-17 00:50 +0200
Message-ID <tHTrX-3gi-9@gated-at.bofh.it> (permalink)
References <tFUVb-5Qu-3@gated-at.bofh.it> <tFUVc-5Qu-15@gated-at.bofh.it>
Organization linux.* mail to news gateway

Show all headers | View raw


Hi Gilad,

On Thu, May 11, 2017 at 02:53:43PM +0300, Gilad Ben-Yossef wrote:
> drbg_kcapi_sym_ctr() was using wait_for_completion_interruptible() to
> wait for completion of async crypto op but if a signal occurs it
> may return before DMA ops of HW crypto provider finish, thus
> corrupting the output buffer.
> 
> Resolve this by using wait_for_completion() instead.
> 
> Reported-by: Eric Biggers <ebiggers3@gmail.com>
> Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com>
> CC: stable@vger.kernel.org
> ---
>  crypto/drbg.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/crypto/drbg.c b/crypto/drbg.c
> index fa749f4..fa9054d 100644
> --- a/crypto/drbg.c
> +++ b/crypto/drbg.c
> @@ -1767,8 +1767,7 @@ static int drbg_kcapi_sym_ctr(struct drbg_state *drbg,
>  			break;
>  		case -EINPROGRESS:
>  		case -EBUSY:
> -			ret = wait_for_completion_interruptible(
> -				&drbg->ctr_completion);
> +			ret = wait_for_completion(&drbg->ctr_completion);
>  			if (!ret && !drbg->ctr_async_err) {
>  				reinit_completion(&drbg->ctr_completion);
>  				break;
> -- 

wait_for_completion() doesn't return a value.  This was fixed in the next patch,
but it should be done in this patch.

Eric

Back to linux.kernel | Previous | Next | Find similar | Unroll thread


Thread

Re: [PATCH 2/4] crypto: drbg wait for crypto op not signal safe Eric Biggers <ebiggers3@gmail.com> - 2017-05-17 00:50 +0200

csiph-web