crypto: skcipher - fix mismatch between mapping and unmapping order

Local kunmaps have to be unmapped in the opposite order from which they
were mapped.  My recent change flipped the unmap order in the
SKCIPHER_WALK_DIFF case.  Adjust the mapping side to match.

This fixes a WARN_ON_ONCE that was triggered when running the
crypto-self tests on a 32-bit kernel with
CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP=y.

Fixes: 95dbd711b1d8 ("crypto: skcipher - use the new scatterwalk functions")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/crypto/skcipher.c b/crypto/skcipher.c
index 53123d3685d5dbb823ff5fff83970e5d7f986f55..66d19c360dd8b111da504e48b51ffccebdc25741 100644 (file)
--- a/crypto/skcipher.c
+++ b/crypto/skcipher.c
@@ -209,12 +209,12 @@ static int skcipher_next_fast(struct skcipher_walk *walk)
        diff |= (u8 *)(sg_page(walk->in.sg) + (walk->in.offset >> PAGE_SHIFT)) -
                (u8 *)(sg_page(walk->out.sg) + (walk->out.offset >> PAGE_SHIFT));
 
-       skcipher_map_src(walk);
-       walk->dst.virt.addr = walk->src.virt.addr;
+       skcipher_map_dst(walk);
+       walk->src.virt.addr = walk->dst.virt.addr;
 
        if (diff) {
                walk->flags |= SKCIPHER_WALK_DIFF;
-               skcipher_map_dst(walk);
+               skcipher_map_src(walk);
        }
 
        return 0;