Hi:

This patch fixes unexpected EINVAL failures on recvmsg when
encrypting/decrypting due to unaligned receive buffers.

commit bc97e57eb21f8db55bf0e1f182d384e75b2e3c99
Author: Herbert Xu <[email protected]>
Date:   Tue Nov 30 17:04:31 2010 +0800

    crypto: algif_skcipher - Handle unaligned receive buffer
    
    As it is if user-space passes through a receive buffer that's not
    aligned to to the cipher block size, we'll end up encrypting or
    decrypting a partial block which causes a spurious EINVAL to be
    returned.
    
    This patch fixes this by moving the partial block test after the
    af_alg_make_sg call.
    
    Signed-off-by: Herbert Xu <[email protected]>

diff --git a/crypto/algif_skcipher.c b/crypto/algif_skcipher.c
index 1f33480..6a6dfc0 100644
--- a/crypto/algif_skcipher.c
+++ b/crypto/algif_skcipher.c
@@ -454,17 +454,17 @@ static int skcipher_recvmsg(struct kiocb *unused, struct 
socket *sock,
 
                        used = min_t(unsigned long, used, seglen);
 
+                       used = af_alg_make_sg(&ctx->rsgl, from, used, 1);
+                       err = used;
+                       if (err < 0)
+                               goto unlock;
+
                        if (ctx->more || used < ctx->used)
                                used -= used % bs;
 
                        err = -EINVAL;
                        if (!used)
-                               goto unlock;
-
-                       used = af_alg_make_sg(&ctx->rsgl, from, used, 1);
-                       err = used;
-                       if (err < 0)
-                               goto unlock;
+                               goto free;
 
                        ablkcipher_request_set_crypt(&ctx->req, sg,
                                                     ctx->rsgl.sg, used,
@@ -476,6 +476,7 @@ static int skcipher_recvmsg(struct kiocb *unused, struct 
socket *sock,
                                        crypto_ablkcipher_decrypt(&ctx->req),
                                &ctx->completion);
 
+free:
                        af_alg_free_sg(&ctx->rsgl);
 
                        if (err)

Cheers,
-- 
Email: Herbert Xu <[email protected]>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
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