[3.16.y-ckt stable] Patch "crypto: algif - avoid excessive use of socket buffer in skcipher" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    crypto: algif - avoid excessive use of socket buffer in skcipher

to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.16.y-queue

This patch is scheduled to be released in version 3.16.7-ckt2.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.16.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From 27d507ca56491959f3172b44fac263c3d330dc35 Mon Sep 17 00:00:00 2001
From: Ondrej Kozina <okozina at redhat.com>
Date: Mon, 25 Aug 2014 11:49:54 +0200
Subject: crypto: algif - avoid excessive use of socket buffer in skcipher

commit e2cffb5f493a8b431dc87124388ea59b79f0bccb upstream.

On archs with PAGE_SIZE >= 64 KiB the function skcipher_alloc_sgl()
fails with -ENOMEM no matter what user space actually requested.
This is caused by the fact sock_kmalloc call inside the function tried
to allocate more memory than allowed by the default kernel socket buffer
size (kernel param net.core.optmem_max).

Signed-off-by: Ondrej Kozina <okozina at redhat.com>
Signed-off-by: Herbert Xu <herbert at gondor.apana.org.au>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 crypto/algif_skcipher.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/crypto/algif_skcipher.c b/crypto/algif_skcipher.c
index a19c027b29bd..83187f497c7c 100644
--- a/crypto/algif_skcipher.c
+++ b/crypto/algif_skcipher.c
@@ -49,7 +49,7 @@ struct skcipher_ctx {
 	struct ablkcipher_request req;
 };

-#define MAX_SGL_ENTS ((PAGE_SIZE - sizeof(struct skcipher_sg_list)) / \
+#define MAX_SGL_ENTS ((4096 - sizeof(struct skcipher_sg_list)) / \
 		      sizeof(struct scatterlist) - 1)

 static inline int skcipher_sndbuf(struct sock *sk)
--
2.1.0