The patch below does not apply to the 4.9-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 7cf81954705b7e5b057f7dc39a7ded54422ab6e1 Mon Sep 17 00:00:00 2001

From: Herbert Xu herbert@gondor.apana.org.au Date: Fri, 29 May 2020 14:54:43 +1000 Subject: [PATCH] crypto: algif_skcipher - Cap recv SG list at ctx->used

Somewhere along the line the cap on the SG list length for receive was lost. This patch restores it and removes the subsequent test which is now redundant.

Fixes: 2d97591ef43d ("crypto: af_alg - consolidation of...") Cc: stable@vger.kernel.org Signed-off-by: Herbert Xu herbert@gondor.apana.org.au Reviewed-by: Stephan Mueller smueller@chronox.de Signed-off-by: Herbert Xu herbert@gondor.apana.org.au

diff --git a/crypto/algif_skcipher.c b/crypto/algif_skcipher.c index e2c8ab408bed..4c3bdffe0c3a 100644 --- a/crypto/algif_skcipher.c +++ b/crypto/algif_skcipher.c @@ -74,14 +74,10 @@ static int _skcipher_recvmsg(struct socket *sock, struct msghdr *msg, return PTR_ERR(areq);

/* convert iovecs of output buffers into RX SGL */ - err = af_alg_get_rsgl(sk, msg, flags, areq, -1, &len); + err = af_alg_get_rsgl(sk, msg, flags, areq, ctx->used, &len); if (err) goto free;

- /* Process only as much RX buffers for which we have TX data */ - if (len > ctx->used) - len = ctx->used; - /* * If more buffers are to be expected to be processed, process only * full block size buffers.