[PATCH AUTOSEL 6.0 01/30] cxl/mbox: Add a check on input payload size

[Sasha Levin]

From: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>

[ Upstream commit cf00b33058b196b4db928419dde68993b15a975b ]

A bug in the LSA code resulted in transfers slightly larger
than the mailbox size. Let us make it easier to catch similar
issues in future by adding a low level check.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20220815154044.24733-2-Jonathan.Cameron@xxxxxxxxxx
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/cxl/core/mbox.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c
index 16176b9278b4..0c90f13870a4 100644
--- a/drivers/cxl/core/mbox.c
+++ b/drivers/cxl/core/mbox.c
@@ -174,7 +174,7 @@ int cxl_mbox_send_cmd(struct cxl_dev_state *cxlds, u16 opcode, void *in,
 	};
 	int rc;
 
-	if (out_size > cxlds->payload_size)
+	if (in_size > cxlds->payload_size || out_size > cxlds->payload_size)
 		return -E2BIG;
 
 	rc = cxlds->mbox_send(cxlds, &mbox_cmd);
-- 
2.35.1