[PATCH AUTOSEL 4.19 01/25] ipmi:ssif: Handle a possible NULL pointer reference

[Sasha Levin]

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 af44db2dfb68a..fec679433f72d 100644
--- a/drivers/char/ipmi/ipmi_ssif.c
+++ b/drivers/char/ipmi/ipmi_ssif.c
@@ -735,10 +735,14 @@ 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