Patch "ipmi: fix unsigned long underflow" has been added to the 4.13-stable tree

This is a note to let you know that I've just added the patch titled

ipmi: fix unsigned long underflow

to the 4.13-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
ipmi-fix-unsigned-long-underflow.patch
and it can be found in the queue-4.13 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Corey Minyard <[email protected]>
Date: Sat, 29 Jul 2017 21:14:55 -0500
Subject: ipmi: fix unsigned long underflow

From: Corey Minyard <[email protected]>

commit 392a17b10ec4320d3c0e96e2a23ebaad1123b989 upstream.

When I set the timeout to a specific value such as 500ms, the timeout event will not happen in time due to the overflow in function check_msg_timeout:
...

	ent->timeout -= timeout_period;
	if (ent->timeout > 0)
		return;

...

The type of timeout_period is long, but ent->timeout is unsigned long. This patch makes the type consistent.

---
 drivers/char/ipmi/ipmi_msghandler.c |   10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

@@ -4030,7 +4030,8 @@ smi_from_recv_msg(ipmi_smi_t intf, struc
 }
 
 static void check_msg_timeout(ipmi_smi_t intf, struct seq_table *ent,
-			      struct list_head *timeouts, long timeout_period,
+			      struct list_head *timeouts,
+			      unsigned long timeout_period,
 			      int slot, unsigned long *flags,
 			      unsigned int *waiting_msgs)
 {

@@ -4043,8 +4044,8 @@ static void check_msg_timeout(ipmi_smi_t
 	if (!ent->inuse)
 		return;
 
-	ent->timeout -= timeout_period;
-	if (ent->timeout > 0) {
+	if (timeout_period < ent->timeout) {
+		ent->timeout -= timeout_period;
 		(*waiting_msgs)++;
 		return;
 	}

@@ -4110,7 +4111,8 @@ static void check_msg_timeout(ipmi_smi_t
 	}
 }
 
-static unsigned int ipmi_timeout_handler(ipmi_smi_t intf, long timeout_period)
+static unsigned int ipmi_timeout_handler(ipmi_smi_t intf,
+					 unsigned long timeout_period)
 {
 	struct list_head     timeouts;
 	struct ipmi_recv_msg *msg, *msg2;

Patches currently in stable-queue which might be from [email protected] are

queue-4.13/ipmi-fix-unsigned-long-underflow.patch