[PATCH 3.16.y-ckt 068/254] crypto: algif - avoid excessive use of socket buffer in skcipher

From: Luis Henriques
Date: Tue Nov 25 2014 - 06:44:41 EST


3.16.7-ckt2 -stable review patch. If anyone has any objections, please let me know.

------------------

From: Ondrej Kozina <okozina@xxxxxxxxxx>

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@xxxxxxxxxx>
Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Luis Henriques <luis.henriques@xxxxxxxxxxxxx>
---
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

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