leandrof/linux
1
0
Fork 0
forked from Minki/linux
Code Issues Pull Requests Packages Projects Releases Wiki Activity

crypto: skcipher - Fix crash on zero-length input

Browse Source 
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: b286d8b1a6 ("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>
This commit is contained in:
Herbert Xu 2017-10-07 11:29:48 +08:00
parent 9039f3ef44
commit 0cabf2af6f
1 changed files with 11 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

17
crypto/skcipher.c
View File

@ -426,14 +426,9 @@ static int skcipher_copy_iv(struct skcipher_walk *walk)
static int skcipher_walk_first(struct skcipher_walk *walk) static int skcipher_walk_first(struct skcipher_walk *walk)
{ {
walk->nbytes = 0;
if (WARN_ON_ONCE(in_irq())) if (WARN_ON_ONCE(in_irq()))
return -EDEADLK; return -EDEADLK;
if (unlikely(!walk->total))
return 0;
walk->buffer = NULL; walk->buffer = NULL;
if (unlikely(((unsigned long)walk->iv & walk->alignmask))) { if (unlikely(((unsigned long)walk->iv & walk->alignmask))) {
int err = skcipher_copy_iv(walk); 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); 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->in, req->src);
scatterwalk_start(&walk->out, req->dst); scatterwalk_start(&walk->out, req->dst);
walk->total = req->cryptlen;
walk->iv = req->iv; walk->iv = req->iv;
walk->oiv = 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); struct crypto_aead *tfm = crypto_aead_reqtfm(req);
int err; int err;
walk->nbytes = 0;
if (unlikely(!walk->total))
return 0;
walk->flags &= ~SKCIPHER_WALK_PHYS; walk->flags &= ~SKCIPHER_WALK_PHYS;
scatterwalk_start(&walk->in, req->src); scatterwalk_start(&walk->in, req->src);