[PATCH 4.14 006/126] ipmi:ssif: Handle a possible NULL pointer reference

[Greg Kroah-Hartman]

From: Corey Minyard <cminyard@xxxxxxxxxx>

[ Upstream commit 6b8526d3abc02c08a2f888e8c20b7ac9e5776dfe ]

In error cases a NULL can be passed to memcpy.  The length will always
be zero, so it doesn't really matter, but go ahead and check for NULL,
anyway, to be more precise and avoid static analysis errors.

Reported-by: kbuild test robot <lkp@xxxxxxxxx>
Signed-off-by: Corey Minyard <cminyard@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/char/ipmi/ipmi_ssif.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/char/ipmi/ipmi_ssif.c b/drivers/char/ipmi/ipmi_ssif.c
index 941bffd9b49cd..0146bc3252c5a 100644
--- a/drivers/char/ipmi/ipmi_ssif.c
+++ b/drivers/char/ipmi/ipmi_ssif.c
@@ -750,10 +750,14 @@ static void msg_done_handler(struct ssif_info *ssif_info, int result,
 	flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
 	msg = ssif_info->curr_msg;
 	if (msg) {
+		if (data) {
+			if (len > IPMI_MAX_MSG_LENGTH)
+				len = IPMI_MAX_MSG_LENGTH;
+			memcpy(msg->rsp, data, len);
+		} else {
+			len = 0;
+		}
 		msg->rsp_size = len;
-		if (msg->rsp_size > IPMI_MAX_MSG_LENGTH)
-			msg->rsp_size = IPMI_MAX_MSG_LENGTH;
-		memcpy(msg->rsp, data, msg->rsp_size);
 		ssif_info->curr_msg = NULL;
 	}
 
-- 
2.20.1