From 6ed42ccca59db6c871f00c5746a769e5154324b6 Mon Sep 17 00:00:00 2001 From: Gilad Ben-Yossef Date: Tue, 15 Jan 2019 15:43:17 +0200 Subject: [PATCH] crypto: ccree - don't copy zero size ciphertext commit 2b5ac17463dcb2411fed506edcf259a89bb538ba upstream. For decryption in CBC mode we need to save the last ciphertext block for use as the next IV. However, we were trying to do this also with zero sized ciphertext resulting in a panic. Fix this by only doing the copy if the ciphertext length is at least of IV size. Signed-off-by: Gilad Ben-Yossef Cc: stable@vger.kernel.org Signed-off-by: Herbert Xu Signed-off-by: Greg Kroah-Hartman --- drivers/crypto/ccree/cc_cipher.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/crypto/ccree/cc_cipher.c b/drivers/crypto/ccree/cc_cipher.c index 7b9aa93..54a3916 100644 --- a/drivers/crypto/ccree/cc_cipher.c +++ b/drivers/crypto/ccree/cc_cipher.c @@ -783,7 +783,8 @@ static int cc_cipher_decrypt(struct skcipher_request *req) memset(req_ctx, 0, sizeof(*req_ctx)); - if (ctx_p->cipher_mode == DRV_CIPHER_CBC) { + if ((ctx_p->cipher_mode == DRV_CIPHER_CBC) && + (req->cryptlen >= ivsize)) { /* Allocate and save the last IV sized bytes of the source, * which will be lost in case of in-place decryption. -- 2.7.4