UBUNTU: Ubuntu-4.15.0-96.97

[mirror_ubuntu-bionic-kernel.git] / crypto / skcipher.c

diff --git a/crypto/skcipher.c b/crypto/skcipher.c
index 11af5fd6a443570550e1dac5b0a429b2cae801b1..915bbae3d5bc4e7a8c7bd0b926a47fac05c5cf42 100644 (file)
--- a/crypto/skcipher.c
+++ b/crypto/skcipher.c
@@ -108,18 +108,21 @@ static int skcipher_done_slow(struct skcipher_walk *walk, unsigned int bsize)
 
 int skcipher_walk_done(struct skcipher_walk *walk, int err)
 {
-       unsigned int n = walk->nbytes - err;
-       unsigned int nbytes;
-
-       nbytes = walk->total - n;
-
-       if (unlikely(err < 0)) {
-               nbytes = 0;
-               n = 0;
-       } else if (likely(!(walk->flags & (SKCIPHER_WALK_PHYS |
-                                          SKCIPHER_WALK_SLOW |
-                                          SKCIPHER_WALK_COPY |
-                                          SKCIPHER_WALK_DIFF)))) {
+       unsigned int n = walk->nbytes;
+       unsigned int nbytes = 0;
+
+       if (!n)
+               goto finish;
+
+       if (likely(err >= 0)) {
+               n -= err;
+               nbytes = walk->total - n;
+       }
+
+       if (likely(!(walk->flags & (SKCIPHER_WALK_PHYS |
+                                   SKCIPHER_WALK_SLOW |
+                                   SKCIPHER_WALK_COPY |
+                                   SKCIPHER_WALK_DIFF)))) {
 unmap_src:
                skcipher_unmap_src(walk);
        } else if (walk->flags & SKCIPHER_WALK_DIFF) {
@@ -130,7 +133,13 @@ unmap_src:
                memcpy(walk->dst.virt.addr, walk->page, n);
                skcipher_unmap_dst(walk);
        } else if (unlikely(walk->flags & SKCIPHER_WALK_SLOW)) {
-               if (WARN_ON(err)) {
+               if (err > 0) {
+                       /*
+                        * Didn't process all bytes.  Either the algorithm is
+                        * broken, or this was the last step and it turned out
+                        * the message wasn't evenly divisible into blocks but
+                        * the algorithm requires it.
+                        */
                        err = -EINVAL;
                        nbytes = 0;
                } else
@@ -141,7 +150,7 @@ unmap_src:
                err = 0;
 
        walk->total = nbytes;
-       walk->nbytes = nbytes;
+       walk->nbytes = 0;
 
        scatterwalk_advance(&walk->in, n);
        scatterwalk_advance(&walk->out, n);
@@ -154,6 +163,7 @@ unmap_src:
                return skcipher_walk_next(walk);
        }
 
+finish:
        /* Short-circuit for the common/fast path. */
        if (!((unsigned long)walk->buffer | (unsigned long)walk->page))
                goto out;
@@ -399,7 +409,7 @@ static int skcipher_copy_iv(struct skcipher_walk *walk)
        unsigned size;
        u8 *iv;
 
-       aligned_bs = ALIGN(bs, alignmask);
+       aligned_bs = ALIGN(bs, alignmask + 1);
 
        /* Minimum size to align buffer by alignmask. */
        size = alignmask & ~a;