There are corner cases where skcipher_walk_aead_[en|de]crypt() may be invoked with a zero sized input, which is not rejected by the walker code, but results in the skcipher_walk structure to not be fully initialized. This will leave stale values in its page and buffer members, which will be subsequently passed to kfree() or free_page() by skcipher_walk_done(), resulting in a crash if those routines fail to identify them as in valid inputs. Fix this by setting page and buffer to NULL even if the size of the input is zero. Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx> --- crypto/skcipher.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/crypto/skcipher.c b/crypto/skcipher.c index a15376245416..93fdacf49697 100644 --- a/crypto/skcipher.c +++ b/crypto/skcipher.c @@ -511,6 +511,8 @@ static int skcipher_walk_aead_common(struct skcipher_walk *walk, walk->nbytes = 0; walk->iv = req->iv; walk->oiv = req->iv; + walk->buffer = NULL; + walk->page = NULL; if (unlikely(!walk->total)) return 0; -- 2.20.1
