This is a note to let you know that I've just added the patch titled ipmi: fix unsigned long underflow to the 4.9-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-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 392a17b10ec4320d3c0e96e2a23ebaad1123b989 Mon Sep 17 00:00:00 2001 From: Corey Minyard <cminyard@xxxxxxxxxx> Date: Sat, 29 Jul 2017 21:14:55 -0500 Subject: ipmi: fix unsigned long underflow From: Corey Minyard <cminyard@xxxxxxxxxx> 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. Reported-by: Weilong Chen <chenweilong@xxxxxxxxxx> Signed-off-by: Corey Minyard <cminyard@xxxxxxxxxx> Tested-by: Weilong Chen <chenweilong@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/char/ipmi/ipmi_msghandler.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) --- a/drivers/char/ipmi/ipmi_msghandler.c +++ b/drivers/char/ipmi/ipmi_msghandler.c @@ -4029,7 +4029,8 @@ 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) { @@ -4042,8 +4043,8 @@ 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; } @@ -4109,7 +4110,8 @@ 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 cminyard@xxxxxxxxxx are queue-4.9/ipmi-fix-unsigned-long-underflow.patch