[PATCH V2] ipmi: ssif: potential NULL dereference in msg_done_handler()
From: Haowen Bai
Date: Sat Apr 02 2022 - 00:01:38 EST
msg could be null without checking null and return, but still dereference
msg->rsp[2] and will lead to a null pointer trigger.
Signed-off-by: Haowen Bai <baihaowen@xxxxxxxxx>
---
V1->V2: check msg both cases that also uses msg; add logs;
drivers/char/ipmi/ipmi_ssif.c | 19 ++++++++++++++++++-
1 file changed, 18 insertions(+), 1 deletion(-)
diff --git a/drivers/char/ipmi/ipmi_ssif.c b/drivers/char/ipmi/ipmi_ssif.c
index f199cc194844..eb6bdd44b69e 100644
--- a/drivers/char/ipmi/ipmi_ssif.c
+++ b/drivers/char/ipmi/ipmi_ssif.c
@@ -758,8 +758,11 @@ static void msg_done_handler(struct ssif_info *ssif_info, int result,
switch (ssif_info->ssif_state) {
case SSIF_NORMAL:
ipmi_ssif_unlock_cond(ssif_info, flags);
- if (!msg)
+ if (!msg) {
+ dev_dbg(&ssif_info->client->dev,
+ "msg was null, case SSIF_NORMAL\n");
break;
+ }
if (result < 0)
return_hosed_msg(ssif_info, msg);
@@ -814,6 +817,13 @@ static void msg_done_handler(struct ssif_info *ssif_info, int result,
break;
case SSIF_GETTING_EVENTS:
+ if (!msg) {
+ ipmi_ssif_unlock_cond(ssif_info, flags);
+ dev_dbg(&ssif_info->client->dev,
+ "msg was null, case SSIF_GETTING_EVENTS\n");
+ break;
+ }
+
if ((result < 0) || (len < 3) || (msg->rsp[2] != 0)) {
/* Error getting event, probably done. */
msg->done(msg);
@@ -838,6 +848,13 @@ static void msg_done_handler(struct ssif_info *ssif_info, int result,
break;
case SSIF_GETTING_MESSAGES:
+ if (!msg) {
+ ipmi_ssif_unlock_cond(ssif_info, flags);
+ dev_dbg(&ssif_info->client->dev,
+ "msg was null, case SSIF_GETTING_MESSAGES\n");
+ break;
+ }
+
if ((result < 0) || (len < 3) || (msg->rsp[2] != 0)) {
/* Error getting event, probably done. */
msg->done(msg);
--
2.7.4