[PATCH 5.4 171/232] crypto: ccree - only try to map auth tag if needed

From: Greg Kroah-Hartman
Date: Thu Apr 16 2020 - 10:13:41 EST


From: Gilad Ben-Yossef <gilad@xxxxxxxxxxxxx>

commit 504e84abec7a635b861afd8d7f92ecd13eaa2b09 upstream.

Make sure to only add the size of the auth tag to the source mapping
for encryption if it is an in-place operation. Failing to do this
previously caused us to try and map auth size len bytes from a NULL
mapping and crashing if both the cryptlen and assoclen are zero.

Reported-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
Tested-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
Signed-off-by: Gilad Ben-Yossef <gilad@xxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx # v4.19+
Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/crypto/ccree/cc_buffer_mgr.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

--- a/drivers/crypto/ccree/cc_buffer_mgr.c
+++ b/drivers/crypto/ccree/cc_buffer_mgr.c
@@ -1109,9 +1109,11 @@ int cc_map_aead_request(struct cc_drvdat
}

size_to_map = req->cryptlen + areq_ctx->assoclen;
- if (areq_ctx->gen_ctx.op_type == DRV_CRYPTO_DIRECTION_ENCRYPT)
+ /* If we do in-place encryption, we also need the auth tag */
+ if ((areq_ctx->gen_ctx.op_type == DRV_CRYPTO_DIRECTION_ENCRYPT) &&
+ (req->src == req->dst)) {
size_to_map += authsize;
-
+ }
if (is_gcm4543)
size_to_map += crypto_aead_ivsize(tfm);
rc = cc_map_sg(dev, req->src, size_to_map, DMA_BIDIRECTIONAL,