4.19-stable review patch. If anyone has any objections, please let me know.
------------------ From: Gilad Ben-Yossef <[email protected]> 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 <[email protected]> Cc: [email protected] Signed-off-by: Herbert Xu <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- drivers/crypto/ccree/cc_cipher.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/drivers/crypto/ccree/cc_cipher.c +++ b/drivers/crypto/ccree/cc_cipher.c @@ -783,7 +783,8 @@ static int cc_cipher_decrypt(struct skci 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.
