Techwizz/kernel-fxtec-pro1x
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity

IB/umad: Fix use-after-free on close

Browse source 
Avoid that closing /dev/infiniband/umad<n> or /dev/infiniband/issm<n>
triggers a use-after-free.  __fput() invokes f_op->release() before it
invokes cdev_put().  Make sure that the ib_umad_device structure is
freed by the cdev_put() call instead of f_op->release().  This avoids
that changing the port mode from IB into Ethernet and back to IB
followed by restarting opensmd triggers the following kernel oops:

    general protection fault: 0000 [#1] PREEMPT SMP
    RIP: 0010:[<ffffffff810cc65c>]  [<ffffffff810cc65c>] module_put+0x2c/0x170
    Call Trace:
     [<ffffffff81190f20>] cdev_put+0x20/0x30
     [<ffffffff8118e2ce>] __fput+0x1ae/0x1f0
     [<ffffffff8118e35e>] ____fput+0xe/0x10
     [<ffffffff810723bc>] task_work_run+0xac/0xe0
     [<ffffffff81002a9f>] do_notify_resume+0x9f/0xc0
     [<ffffffff814b8398>] int_signal+0x12/0x17

Reference: https://bugzilla.kernel.org/show_bug.cgi?id=75051
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Yann Droneaud <ydroneaud@opteya.com>
Cc: <stable@vger.kernel.org> # 3.x: 8ec0a0e6b5: IB/umad: Fix error handling
Signed-off-by: Roland Dreier <roland@purestorage.com>
This commit is contained in:
Bart Van Assche 2014-06-06 18:25:04 +02:00 committed by Roland Dreier
parent 584482ac80
commit 60e1751cb5
1 changed files with 19 additions and 11 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

30
drivers/infiniband/core/user_mad.c
View file

@ -98,7 +98,7 @@ struct ib_umad_port {
struct ib_umad_device {
int start_port, end_port;
struct kref ref;
struct kobject kobj;
struct ib_umad_port port[0];
};
@ -134,14 +134,18 @@ static DECLARE_BITMAP(dev_map, IB_UMAD_MAX_PORTS);
static void ib_umad_add_one(struct ib_device *device);
static void ib_umad_remove_one(struct ib_device *device);
static void ib_umad_release_dev(struct kref *ref)
static void ib_umad_release_dev(struct kobject *kobj)
{
struct ib_umad_device *dev =
container_of(ref, struct ib_umad_device, ref);
container_of(kobj, struct ib_umad_device, kobj);
kfree(dev);
}
static struct kobj_type ib_umad_dev_ktype = {
.release = ib_umad_release_dev,
};
static int hdr_size(struct ib_umad_file *file)
{
return file->use_pkey_index ? sizeof (struct ib_user_mad_hdr) :
@ -812,7 +816,7 @@ static int ib_umad_open(struct inode *inode, struct file *filp)
goto out;
}
kref_get(&port->umad_dev->ref);
kobject_get(&port->umad_dev->kobj);
out:
mutex_unlock(&port->file_mutex);
@ -851,7 +855,7 @@ static int ib_umad_close(struct inode *inode, struct file *filp)
mutex_unlock(&file->port->file_mutex);
kfree(file);
kref_put(&dev->ref, ib_umad_release_dev);
kobject_put(&dev->kobj);
return 0;
}
@ -902,7 +906,7 @@ static int ib_umad_sm_open(struct inode *inode, struct file *filp)
if (ret)
goto err_clr_sm_cap;
kref_get(&port->umad_dev->ref);
kobject_get(&port->umad_dev->kobj);
return 0;
@ -932,7 +936,7 @@ static int ib_umad_sm_close(struct inode *inode, struct file *filp)
up(&port->sm_sem);
kref_put(&port->umad_dev->ref, ib_umad_release_dev);
kobject_put(&port->umad_dev->kobj);
return ret;
}
@ -1000,6 +1004,7 @@ static int find_overflow_devnum(void)
}
static int ib_umad_init_port(struct ib_device *device, int port_num,
struct ib_umad_device *umad_dev,
struct ib_umad_port *port)
{
int devnum;
@ -1032,6 +1037,7 @@ static int ib_umad_init_port(struct ib_device *device, int port_num,
cdev_init(&port->cdev, &umad_fops);
port->cdev.owner = THIS_MODULE;
port->cdev.kobj.parent = &umad_dev->kobj;
kobject_set_name(&port->cdev.kobj, "umad%d", port->dev_num);
if (cdev_add(&port->cdev, base, 1))
goto err_cdev;
@ -1050,6 +1056,7 @@ static int ib_umad_init_port(struct ib_device *device, int port_num,
base += IB_UMAD_MAX_PORTS;
cdev_init(&port->sm_cdev, &umad_sm_fops);
port->sm_cdev.owner = THIS_MODULE;
port->sm_cdev.kobj.parent = &umad_dev->kobj;
kobject_set_name(&port->sm_cdev.kobj, "issm%d", port->dev_num);
if (cdev_add(&port->sm_cdev, base, 1))
goto err_sm_cdev;
@ -1143,7 +1150,7 @@ static void ib_umad_add_one(struct ib_device *device)
if (!umad_dev)
return;
kref_init(&umad_dev->ref);
kobject_init(&umad_dev->kobj, &ib_umad_dev_ktype);
umad_dev->start_port = s;
umad_dev->end_port = e;
@ -1151,7 +1158,8 @@ static void ib_umad_add_one(struct ib_device *device)
for (i = s; i <= e; ++i) {
umad_dev->port[i - s].umad_dev = umad_dev;
if (ib_umad_init_port(device, i, &umad_dev->port[i - s]))
if (ib_umad_init_port(device, i, umad_dev,
&umad_dev->port[i - s]))
goto err;
}
@ -1163,7 +1171,7 @@ static void ib_umad_add_one(struct ib_device *device)
while (--i >= s)
ib_umad_kill_port(&umad_dev->port[i - s]);
kref_put(&umad_dev->ref, ib_umad_release_dev);
kobject_put(&umad_dev->kobj);
}
static void ib_umad_remove_one(struct ib_device *device)
@ -1177,7 +1185,7 @@ static void ib_umad_remove_one(struct ib_device *device)
for (i = 0; i <= umad_dev->end_port - umad_dev->start_port; ++i)
ib_umad_kill_port(&umad_dev->port[i]);
kref_put(&umad_dev->ref, ib_umad_release_dev);
kobject_put(&umad_dev->kobj);
}
static char *umad_devnode(struct device *dev, umode_t *mode)