From 9206dff15705267c19f8fed391c4fb95975540a3 Mon Sep 17 00:00:00 2001 From: Roland Dreier Date: Wed, 25 Feb 2009 13:27:46 -0800 Subject: [PATCH] IB: Remove sysfs files before unregistering device Move the ib_device_unregister_sysfs() call from ib_dealloc_device() to ib_unregister_device(). The old code allows device unregister to proceed even if some sysfs files are open, which leaves a window where userspace can open a file before a device is removed but then end up reading the file after the device is removed, which leads to various kernel crashes either because the device data structure is freed or because the low-level driver code is gone after module removal. By not returning from ib_unregister_device() until after all sysfs entries are removed, we make sure that data structures and/or module code is not freed until after all sysfs access is done. Reported-by: Jack Morgenstein Signed-off-by: Roland Dreier --- drivers/infiniband/core/device.c | 4 +++- drivers/infiniband/core/sysfs.c | 3 +++ 2 files changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/infiniband/core/device.c b/drivers/infiniband/core/device.c index 7913b804311e..d1fba4153332 100644 --- a/drivers/infiniband/core/device.c +++ b/drivers/infiniband/core/device.c @@ -193,7 +193,7 @@ void ib_dealloc_device(struct ib_device *device) BUG_ON(device->reg_state != IB_DEV_UNREGISTERED); - ib_device_unregister_sysfs(device); + kobject_put(&device->dev.kobj); } EXPORT_SYMBOL(ib_dealloc_device); @@ -348,6 +348,8 @@ void ib_unregister_device(struct ib_device *device) mutex_unlock(&device_mutex); + ib_device_unregister_sysfs(device); + spin_lock_irqsave(&device->client_data_lock, flags); list_for_each_entry_safe(context, tmp, &device->client_data_list, list) kfree(context); diff --git a/drivers/infiniband/core/sysfs.c b/drivers/infiniband/core/sysfs.c index b43f7d3682d3..5270aeb56e9e 100644 --- a/drivers/infiniband/core/sysfs.c +++ b/drivers/infiniband/core/sysfs.c @@ -848,6 +848,9 @@ void ib_device_unregister_sysfs(struct ib_device *device) struct kobject *p, *t; struct ib_port *port; + /* Hold kobject until ib_dealloc_device() */ + kobject_get(&device->dev.kobj); + list_for_each_entry_safe(p, t, &device->port_list, entry) { list_del(&p->entry); port = container_of(p, struct ib_port, kobj);