Re: [PATCH 2/11] crypto: scatterwalk - Add missing sg_init_table to scatterwalk_ffwd

[Stephan Mueller <smueller@chronox.de>]

Am Mittwoch, 27. Mai 2015, 14:37:27 schrieb Herbert Xu:

Hi Herbert,

>We need to call sg_init_table as otherwise the first entry may
>inadvertently become the last.
>
>Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Although the following remark is to the previous patch to add 
scatterwalk_ffwd, I would like to ask it here:
>---
>
> crypto/scatterwalk.c |    1 +
> 1 file changed, 1 insertion(+)
>
>diff --git a/crypto/scatterwalk.c b/crypto/scatterwalk.c
>index 8690324..2ef9cbb 100644
>--- a/crypto/scatterwalk.c
>+++ b/crypto/scatterwalk.c
>@@ -158,6 +158,7 @@ struct scatterlist *scatterwalk_ffwd(struct scatterlist
>dst[2],
>		src = sg_next(src);

Shouldn't there be a check for src == NULL here? I see the scatterwalk_ffwd 
being used in the IV generators where they simply use the AD len and others. 
For AF_ALG, those values may be set by user space in a deliberately wrong way 
(e.g. more AD len than provided buffers).


Ciao
Stephan