* [PATCH] crypto: AF_ALG - remove SGL end indicator when chaining
@ 2017-08-30 16:59 Stephan Müller
2017-09-20 8:32 ` Herbert Xu
0 siblings, 1 reply; 6+ messages in thread
From: Stephan Müller @ 2017-08-30 16:59 UTC (permalink / raw)
To: herbert; +Cc: linux-crypto, stable
The SGL is MAX_SGL_ENTS + 1 in size. The last SG entry is used for the
chaining and is properly updated with the sg_chain invocation. During
the filling-in of the initial SG entries, sg_mark_end is called for each
SG entry. This is appropriate as long as no additional SGL is chained
with the current SGL. However, when a new SGL is chained and the last
SG entry is updated with sg_chain, the last but one entry still contains
the end marker from the sg_mark_end. This end marker must be removed as
otherwise a walk of the chained SGLs will cause a NULL pointer
dereference at the last but one SG entry, because sg_next will return
NULL.
Fixes: 8ff590903d5fc ("crypto: algif_skcipher - User-space interface
for skcipher operations")
CC: <stable@vger.kernel.org>
CC: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Stephan Mueller <smueller@chronox.de>
---
crypto/algif_skcipher.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/crypto/algif_skcipher.c b/crypto/algif_skcipher.c
index 43839b00fe6c..62449a8f14ce 100644
--- a/crypto/algif_skcipher.c
+++ b/crypto/algif_skcipher.c
@@ -139,8 +139,10 @@ static int skcipher_alloc_sgl(struct sock *sk)
sg_init_table(sgl->sg, MAX_SGL_ENTS + 1);
sgl->cur = 0;
- if (sg)
+ if (sg) {
sg_chain(sg, MAX_SGL_ENTS + 1, sgl->sg);
+ sg_unmark_end(sg + (MAX_SGL_ENTS - 1));
+ }
list_add_tail(&sgl->list, &ctx->tsgl);
}
--
2.13.5
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: [PATCH] crypto: AF_ALG - remove SGL end indicator when chaining
2017-08-30 16:59 [PATCH] crypto: AF_ALG - remove SGL end indicator when chaining Stephan Müller
@ 2017-09-20 8:32 ` Herbert Xu
2017-09-20 13:47 ` Stephan Mueller
0 siblings, 1 reply; 6+ messages in thread
From: Herbert Xu @ 2017-09-20 8:32 UTC (permalink / raw)
To: Stephan Müller; +Cc: linux-crypto, stable
On Wed, Aug 30, 2017 at 06:59:07PM +0200, Stephan M�ller wrote:
> The SGL is MAX_SGL_ENTS + 1 in size. The last SG entry is used for the
> chaining and is properly updated with the sg_chain invocation. During
> the filling-in of the initial SG entries, sg_mark_end is called for each
> SG entry. This is appropriate as long as no additional SGL is chained
> with the current SGL. However, when a new SGL is chained and the last
> SG entry is updated with sg_chain, the last but one entry still contains
> the end marker from the sg_mark_end. This end marker must be removed as
> otherwise a walk of the chained SGLs will cause a NULL pointer
> dereference at the last but one SG entry, because sg_next will return
> NULL.
>
> Fixes: 8ff590903d5fc ("crypto: algif_skcipher - User-space interface
> for skcipher operations")
> CC: <stable@vger.kernel.org>
> CC: Herbert Xu <herbert@gondor.apana.org.au>
> Signed-off-by: Stephan Mueller <smueller@chronox.de>
Hmm, this patch does not apply against the current tree. Is this
a stable-only patch?
Cheers,
--
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] crypto: AF_ALG - remove SGL end indicator when chaining
2017-09-20 8:32 ` Herbert Xu
@ 2017-09-20 13:47 ` Stephan Mueller
2017-09-20 17:31 ` Greg KH
0 siblings, 1 reply; 6+ messages in thread
From: Stephan Mueller @ 2017-09-20 13:47 UTC (permalink / raw)
To: Herbert Xu; +Cc: linux-crypto, stable
Am Mittwoch, 20. September 2017, 10:32:09 CEST schrieb Herbert Xu:
Hi Herbert,
>
> Hmm, this patch does not apply against the current tree. Is this
> a stable-only patch?
This would be a stable-only patch. With the overhauling of the AF_ALG memory
handling, this is a no-issue any more.
Thanks
Ciao
Stephan
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] crypto: AF_ALG - remove SGL end indicator when chaining
2017-09-20 13:47 ` Stephan Mueller
@ 2017-09-20 17:31 ` Greg KH
2017-09-21 6:43 ` Stephan Mueller
0 siblings, 1 reply; 6+ messages in thread
From: Greg KH @ 2017-09-20 17:31 UTC (permalink / raw)
To: Stephan Mueller; +Cc: Herbert Xu, linux-crypto, stable
On Wed, Sep 20, 2017 at 03:47:46PM +0200, Stephan Mueller wrote:
> Am Mittwoch, 20. September 2017, 10:32:09 CEST schrieb Herbert Xu:
>
> Hi Herbert,
>
> >
> > Hmm, this patch does not apply against the current tree. Is this
> > a stable-only patch?
>
> This would be a stable-only patch. With the overhauling of the AF_ALG memory
> handling, this is a no-issue any more.
If you want this as a stable-only patch, you need to resend it and
justify it a bunch as to why it isn't in Linus's tree as well.
thanks,
greg k-h
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] crypto: AF_ALG - remove SGL end indicator when chaining
2017-09-20 17:31 ` Greg KH
@ 2017-09-21 6:43 ` Stephan Mueller
2017-09-21 8:04 ` Herbert Xu
0 siblings, 1 reply; 6+ messages in thread
From: Stephan Mueller @ 2017-09-21 6:43 UTC (permalink / raw)
To: Greg KH; +Cc: Herbert Xu, linux-crypto, stable
Am Mittwoch, 20. September 2017, 19:31:33 CEST schrieb Greg KH:
Hi Herbert,
> On Wed, Sep 20, 2017 at 03:47:46PM +0200, Stephan Mueller wrote:
> > Am Mittwoch, 20. September 2017, 10:32:09 CEST schrieb Herbert Xu:
> >
> > Hi Herbert,
> >
> > > Hmm, this patch does not apply against the current tree. Is this
> > > a stable-only patch?
> >
> > This would be a stable-only patch. With the overhauling of the AF_ALG
> > memory handling, this is a no-issue any more.
>
> If you want this as a stable-only patch, you need to resend it and
> justify it a bunch as to why it isn't in Linus's tree as well.
Would you push it or shall I send it?
Thanks
Ciao
Stephan
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] crypto: AF_ALG - remove SGL end indicator when chaining
2017-09-21 6:43 ` Stephan Mueller
@ 2017-09-21 8:04 ` Herbert Xu
0 siblings, 0 replies; 6+ messages in thread
From: Herbert Xu @ 2017-09-21 8:04 UTC (permalink / raw)
To: Stephan Mueller; +Cc: Greg KH, linux-crypto, stable
On Thu, Sep 21, 2017 at 08:43:28AM +0200, Stephan Mueller wrote:
> Am Mittwoch, 20. September 2017, 19:31:33 CEST schrieb Greg KH:
>
> Hi Herbert,
>
> > On Wed, Sep 20, 2017 at 03:47:46PM +0200, Stephan Mueller wrote:
> > > Am Mittwoch, 20. September 2017, 10:32:09 CEST schrieb Herbert Xu:
> > >
> > > Hi Herbert,
> > >
> > > > Hmm, this patch does not apply against the current tree. Is this
> > > > a stable-only patch?
> > >
> > > This would be a stable-only patch. With the overhauling of the AF_ALG
> > > memory handling, this is a no-issue any more.
> >
> > If you want this as a stable-only patch, you need to resend it and
> > justify it a bunch as to why it isn't in Linus's tree as well.
>
> Would you push it or shall I send it?
Please resend it with details as to why this isn't needed on the
mainline kernel, i.e., due to the new code-base which has addressed
the bug in a different way but is too invasive for stable.
Thanks,
--
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2017-09-21 8:04 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2017-08-30 16:59 [PATCH] crypto: AF_ALG - remove SGL end indicator when chaining Stephan Müller
2017-09-20 8:32 ` Herbert Xu
2017-09-20 13:47 ` Stephan Mueller
2017-09-20 17:31 ` Greg KH
2017-09-21 6:43 ` Stephan Mueller
2017-09-21 8:04 ` Herbert Xu
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).