[PATCH 4.4 05/72] ipmi:ssif: Handle a possible NULL pointer reference

From: Greg Kroah-Hartman
Date: Tue Mar 10 2020 - 08:41:00 EST


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 67d23ed2d1a06..29082d99264e8 100644
--- a/drivers/char/ipmi/ipmi_ssif.c
+++ b/drivers/char/ipmi/ipmi_ssif.c
@@ -742,10 +742,14 @@ 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