crypto: algif_skcipher - Load TX SG list after waiting

commit 4f0414e54e4d1893c6f08260693f8ef84c929293 upstream.

We need to load the TX SG list in sendmsg(2) after waiting for
incoming data, not before.

Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Tested-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/crypto/algif_skcipher.c b/crypto/algif_skcipher.c
index 1b02e372a770501806a186388ae8d8630b35e83a..afb43392524f16d0a8cd1f22ca74af6049605bd4 100644 (file)
--- a/crypto/algif_skcipher.c
+++ b/crypto/algif_skcipher.c
@@ -647,13 +647,6 @@ static int skcipher_recvmsg_sync(struct socket *sock, struct msghdr *msg,
 
        lock_sock(sk);
        while (msg_data_left(msg)) {
-               sgl = list_first_entry(&ctx->tsgl,
-                                      struct skcipher_sg_list, list);
-               sg = sgl->sg;
-
-               while (!sg->length)
-                       sg++;
-
                if (!ctx->used) {
                        err = skcipher_wait_for_data(sk, flags);
                        if (err)
@@ -674,6 +667,13 @@ static int skcipher_recvmsg_sync(struct socket *sock, struct msghdr *msg,
                if (!used)
                        goto free;
 
+               sgl = list_first_entry(&ctx->tsgl,
+                                      struct skcipher_sg_list, list);
+               sg = sgl->sg;
+
+               while (!sg->length)
+                       sg++;
+
                skcipher_request_set_crypt(&ctx->req, sg, ctx->rsgl.sg, used,
                                           ctx->iv);