Re: [PATCH] ipmi: ipmi_devintf: compat_ioctl method failes to takeipmi_mutex

From: Corey Minyard
Date: Thu May 16 2013 - 13:47:09 EST

Yes, you are right. I've pulled this in to my tree. Looking at this, ipmi_mutex really should go away and be replaced bu something that scales better, but I guess it's not that critical for IPMI.


On 05/13/2013 02:39 PM, Benjamin LaHaise wrote:
When a 32 bit version of ipmitool is used on a 64 bit kernel, the
ipmi_devintf code fails to correctly acquire ipmi_mutex. This results in
incomplete data being retrieved in some cases, or other possible failures.
Add a wrapper around compat_ipmi_ioctl() to take ipmi_mutex to fix this.
This is probably a candidate for -stable as well.

Signed-off-by: Benjamin LaHaise <bcrl@xxxxxxxxx>
drivers/char/ipmi/ipmi_devintf.c | 14 +++++++++++++-
1 files changed, 13 insertions(+), 1 deletions(-)

diff --git a/drivers/char/ipmi/ipmi_devintf.c b/drivers/char/ipmi/ipmi_devintf.c
index 9eb360f..d5a5f02 100644
--- a/drivers/char/ipmi/ipmi_devintf.c
+++ b/drivers/char/ipmi/ipmi_devintf.c
@@ -837,13 +837,25 @@ static long compat_ipmi_ioctl(struct file *filep, unsigned int cmd,
return ipmi_ioctl(filep, cmd, arg);
+static long unlocked_compat_ipmi_ioctl(struct file *filep, unsigned int cmd,
+ unsigned long arg)
+ int ret;
+ mutex_lock(&ipmi_mutex);
+ ret = compat_ipmi_ioctl(filep, cmd, arg);
+ mutex_unlock(&ipmi_mutex);
+ return ret;
static const struct file_operations ipmi_fops = {
.owner = THIS_MODULE,
.unlocked_ioctl = ipmi_unlocked_ioctl,
- .compat_ioctl = compat_ipmi_ioctl,
+ .compat_ioctl = unlocked_compat_ipmi_ioctl,
.open = ipmi_open,
.release = ipmi_release,

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