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authorIlya Dryomov <idryomov@gmail.com>2023-02-24 20:48:54 +0300
committerIlya Dryomov <idryomov@gmail.com>2023-02-26 22:03:14 +0300
commitf7c4d9b133c7a04ca619355574e96b6abf209fba (patch)
treeb1d192d0f0163165d7a1c2e07e5e52335554f2a1 /drivers
parente027253c4b77d395798600a90b6a96fe4adf4d5e (diff)
downloadlinux-f7c4d9b133c7a04ca619355574e96b6abf209fba.tar.xz
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: 1643dfa4c2c8 ("rbd: introduce a per-device ordered workqueue") Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/block/rbd.c20
1 files changed, 9 insertions, 11 deletions
diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 04453f4a319c..60aed196a2e5 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -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);