Commit f7c4d9b1 authored by Ilya Dryomov's avatar Ilya Dryomov

rbd: avoid use-after-free in do_rbd_add() when rbd_dev_create() fails

If getting an ID or setting up a work queue in rbd_dev_create() fails,
use-after-free on rbd_dev->rbd_client, rbd_dev->spec and rbd_dev->opts
is triggered in do_rbd_add().  The root cause is that the ownership of
these structures is transfered to rbd_dev prematurely and they all end
up getting freed when rbd_dev_create() calls rbd_dev_free() prior to
returning to do_rbd_add().

Found by Linux Verification Center (linuxtesting.org) with SVACE, an
incomplete patch submitted by Natalia Petrova <n.petrova@fintech.ru>.

Cc: stable@vger.kernel.org
Fixes: 1643dfa4 ("rbd: introduce a per-device ordered workqueue")
Signed-off-by: default avatarIlya Dryomov <idryomov@gmail.com>
parent e027253c
......@@ -5292,8 +5292,7 @@ static void rbd_dev_release(struct device *dev)
module_put(THIS_MODULE);
}
static struct rbd_device *__rbd_dev_create(struct rbd_client *rbdc,
struct rbd_spec *spec)
static struct rbd_device *__rbd_dev_create(struct rbd_spec *spec)
{
struct rbd_device *rbd_dev;
......@@ -5338,9 +5337,6 @@ static struct rbd_device *__rbd_dev_create(struct rbd_client *rbdc,
rbd_dev->dev.parent = &rbd_root_dev;
device_initialize(&rbd_dev->dev);
rbd_dev->rbd_client = rbdc;
rbd_dev->spec = spec;
return rbd_dev;
}
......@@ -5353,12 +5349,10 @@ static struct rbd_device *rbd_dev_create(struct rbd_client *rbdc,
{
struct rbd_device *rbd_dev;
rbd_dev = __rbd_dev_create(rbdc, spec);
rbd_dev = __rbd_dev_create(spec);
if (!rbd_dev)
return NULL;
rbd_dev->opts = opts;
/* get an id and fill in device name */
rbd_dev->dev_id = ida_simple_get(&rbd_dev_id_ida, 0,
minor_to_rbd_dev_id(1 << MINORBITS),
......@@ -5375,6 +5369,10 @@ static struct rbd_device *rbd_dev_create(struct rbd_client *rbdc,
/* we have a ref from do_rbd_add() */
__module_get(THIS_MODULE);
rbd_dev->rbd_client = rbdc;
rbd_dev->spec = spec;
rbd_dev->opts = opts;
dout("%s rbd_dev %p dev_id %d\n", __func__, rbd_dev, rbd_dev->dev_id);
return rbd_dev;
......@@ -6736,7 +6734,7 @@ static int rbd_dev_probe_parent(struct rbd_device *rbd_dev, int depth)
goto out_err;
}
parent = __rbd_dev_create(rbd_dev->rbd_client, rbd_dev->parent_spec);
parent = __rbd_dev_create(rbd_dev->parent_spec);
if (!parent) {
ret = -ENOMEM;
goto out_err;
......@@ -6746,8 +6744,8 @@ static int rbd_dev_probe_parent(struct rbd_device *rbd_dev, int depth)
* Images related by parent/child relationships always share
* rbd_client and spec/parent_spec, so bump their refcounts.
*/
__rbd_get_client(rbd_dev->rbd_client);
rbd_spec_get(rbd_dev->parent_spec);
parent->rbd_client = __rbd_get_client(rbd_dev->rbd_client);
parent->spec = rbd_spec_get(rbd_dev->parent_spec);
__set_bit(RBD_DEV_FLAG_READONLY, &parent->flags);
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment