[PATCH] xenbus: don't free other end details too early

From: Jan Beulich
Date: Mon Mar 05 2012 - 12:11:32 EST


The individual drivers' remove functions could legitimately attempt to
access this information (for logging messages if nothing else). Note
that I did not in fact observe a problem anywhere, but I came across
this while looking into the reasons for what turned out to need the
fix at https://lkml.org/lkml/2012/3/5/336 to vsprintf().

Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>

---
drivers/xen/xenbus/xenbus_probe.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

--- 3.3-rc6/drivers/xen/xenbus/xenbus_probe.c
+++ 3.3-rc6-xenbus-remove-details/drivers/xen/xenbus/xenbus_probe.c
@@ -257,11 +257,12 @@ int xenbus_dev_remove(struct device *_de
DPRINTK("%s", dev->nodename);

free_otherend_watch(dev);
- free_otherend_details(dev);

if (drv->remove)
drv->remove(dev);

+ free_otherend_details(dev);
+
xenbus_switch_state(dev, XenbusStateClosed);
return 0;
}



The individual drivers' remove functions could legitimately attempt to
access this information (for logging messages if nothing else). Note
that I did not in fact observe a problem anywhere, but I came across
this while looking into the reasons for what turned out to need the
fix at https://lkml.org/lkml/2012/3/5/336 to vsprintf().

Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>

---
drivers/xen/xenbus/xenbus_probe.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

--- 3.3-rc6/drivers/xen/xenbus/xenbus_probe.c
+++ 3.3-rc6-xenbus-remove-details/drivers/xen/xenbus/xenbus_probe.c
@@ -257,11 +257,12 @@ int xenbus_dev_remove(struct device *_de
DPRINTK("%s", dev->nodename);

free_otherend_watch(dev);
- free_otherend_details(dev);

if (drv->remove)
drv->remove(dev);

+ free_otherend_details(dev);
+
xenbus_switch_state(dev, XenbusStateClosed);
return 0;
}