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authorHerbert Xu <herbert@gondor.apana.org.au>2017-10-07 11:29:48 +0800
committerHerbert Xu <herbert@gondor.apana.org.au>2017-10-07 12:04:32 +0800
commit0cabf2af6f5ac3c88cb106c4e06087a5a39b8e1e (patch)
tree6d612f29ee44e877b4fb546898f729f135ac9900
parent9039f3ef446e9ffa200200c934f049add9e58426 (diff)
crypto: skcipher - Fix crash on zero-length input
The skcipher walk interface doesn't handle zero-length input properly as the old blkcipher walk interface did. This is due to the fact that the length check is done too late. This patch moves the length check forward so that it does the right thing. Fixes: b286d8b1a690 ("crypto: skcipher - Add skcipher walk...") Cc: <stable@vger.kernel.org> Reported-by: Stephan Müller <smueller@chronox.de> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
-rw-r--r--crypto/skcipher.c17
1 files changed, 11 insertions, 6 deletions
diff --git a/crypto/skcipher.c b/crypto/skcipher.c
index 4faa0fd53b0c..d5692e35fab1 100644
--- a/crypto/skcipher.c
+++ b/crypto/skcipher.c
@@ -426,14 +426,9 @@ static int skcipher_copy_iv(struct skcipher_walk *walk)
static int skcipher_walk_first(struct skcipher_walk *walk)
{
- walk->nbytes = 0;
-
if (WARN_ON_ONCE(in_irq()))
return -EDEADLK;
- if (unlikely(!walk->total))
- return 0;
-
walk->buffer = NULL;
if (unlikely(((unsigned long)walk->iv & walk->alignmask))) {
int err = skcipher_copy_iv(walk);
@@ -452,10 +447,15 @@ static int skcipher_walk_skcipher(struct skcipher_walk *walk,
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
+ walk->total = req->cryptlen;
+ walk->nbytes = 0;
+
+ if (unlikely(!walk->total))
+ return 0;
+
scatterwalk_start(&walk->in, req->src);
scatterwalk_start(&walk->out, req->dst);
- walk->total = req->cryptlen;
walk->iv = req->iv;
walk->oiv = req->iv;
@@ -509,6 +509,11 @@ static int skcipher_walk_aead_common(struct skcipher_walk *walk,
struct crypto_aead *tfm = crypto_aead_reqtfm(req);
int err;
+ walk->nbytes = 0;
+
+ if (unlikely(!walk->total))
+ return 0;
+
walk->flags &= ~SKCIPHER_WALK_PHYS;
scatterwalk_start(&walk->in, req->src);