From 1fb37b5692c915edcc2448a6b37255738c7c77e0 Mon Sep 17 00:00:00 2001
From: Gilad Ben-Yossef <gilad@benyossef.com>
Date: Thu, 17 Feb 2022 21:27:26 +0200
Subject: [PATCH] crypto: ccree - don't attempt 0 len DMA mappings
Git-commit: 1fb37b5692c915edcc2448a6b37255738c7c77e0
Patch-mainline: v5.18-rc1
References: git-fixes
Refuse to try mapping zero bytes as this may cause a fault
on some configurations / platforms and it seems the prev.
attempt is not enough and we need to be more explicit.
Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com>
Reported-by: Corentin Labbe <clabbe.montjoie@gmail.com>
Fixes: ce0fc6db38de ("crypto: ccree - protect against empty or NULL
scatterlists")
Tested-by: Corentin Labbe <clabbe.montjoie@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
drivers/crypto/ccree/cc_buffer_mgr.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/drivers/crypto/ccree/cc_buffer_mgr.c b/drivers/crypto/ccree/cc_buffer_mgr.c
index a5e041d9d2cf..11e0278c8631 100644
--- a/drivers/crypto/ccree/cc_buffer_mgr.c
+++ b/drivers/crypto/ccree/cc_buffer_mgr.c
@@ -258,6 +258,13 @@ static int cc_map_sg(struct device *dev, struct scatterlist *sg,
{
int ret = 0;
+ if (!nbytes) {
+ *mapped_nents = 0;
+ *lbytes = 0;
+ *nents = 0;
+ return 0;
+ }
+
*nents = cc_get_sgl_nents(dev, sg, nbytes, lbytes);
if (*nents > max_sg_nents) {
*nents = 0;
--
2.31.1