diff mbox series

[5.4,094/475] crypto: ccree - dont attempt 0 len DMA mappings

Message ID 20220414110857.787624384@linuxfoundation.org
State New
Headers show
Series None | expand

Commit Message

Greg Kroah-Hartman April 14, 2022, 1:07 p.m. UTC 
From: Gilad Ben-Yossef <gilad@benyossef.com>

[ Upstream commit 1fb37b5692c915edcc2448a6b37255738c7c77e0 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/crypto/ccree/cc_buffer_mgr.c | 7 +++++++
 1 file changed, 7 insertions(+)
diff mbox series

Patch

diff --git a/drivers/crypto/ccree/cc_buffer_mgr.c b/drivers/crypto/ccree/cc_buffer_mgr.c
index 954f14bddf1d..dce30ae2b704 100644
--- a/drivers/crypto/ccree/cc_buffer_mgr.c
+++ b/drivers/crypto/ccree/cc_buffer_mgr.c
@@ -295,6 +295,13 @@  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;