@@ -4699,8 +4699,10 @@ out:
return ret;
}
-/* Undo whatever state changes are made by v1 or v2 image probe */
-
+/*
+ * Undo whatever state changes are made by v1 or v2 header info
+ * call.
+ */
static void rbd_dev_unprobe(struct rbd_device *rbd_dev)
{
struct rbd_image_header *header;
@@ -4904,9 +4906,10 @@ static int rbd_dev_image_probe(struct rbd_device
*rbd_dev, bool mapping)
int tmp;
/*
- * Get the id from the image id object. If it's not a
- * format 2 image, we'll get ENOENT back, and we'll assume
- * it's a format 1 image.
+ * Get the id from the image id object. Unless there's an
+ * error, rbd_dev->spec->image_id will be filled in with
+ * a dynamically-allocated string, and rbd_dev->image_format
+ * will be set to either 1 or 2.
*/
ret = rbd_dev_image_id(rbd_dev);
Bjorn Helgaas pointed out that a recent commit introduced a use-after-free condition in an error path for rbd_add(). He correctly stated: I think b536f69a3a5 "rbd: set up devices only for mapped images" introduced a use-after-free error in rbd_add(): ... If rbd_dev_device_setup() returns an error, we call rbd_dev_image_release(), which ultimately kfrees rbd_dev. Then we call rbd_dev_destroy(), which references fields in the already-freed rbd_dev struct before kfreeing it again. The simple fix is to return the error code after the call to rbd_dev_image_release(). Closer examination revealed that there's no need to clean up ceph_opts or rbd_opts in that function, so fix that too. Update some other comments that have also become out of date. Reported-by: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Alex Elder <elder@inktank.com> --- drivers/block/rbd.c | 21 ++++++++++++--------- 1 file changed, 12 insertions(+), 9 deletions(-) if (ret) @@ -4994,7 +4997,7 @@ static ssize_t rbd_add(struct bus_type *bus, rc = PTR_ERR(rbdc); goto err_out_args; } - ceph_opts = NULL; /* rbd_dev client now owns this */ + ceph_opts = NULL; /* rbd_get_client() consumes this */ /* pick the pool */ osdc = &rbdc->client->osdc; @@ -5033,14 +5036,14 @@ static ssize_t rbd_add(struct bus_type *bus, return count; rbd_dev_image_release(rbd_dev); + + return rc; + err_out_rbd_dev: rbd_dev_destroy(rbd_dev); err_out_client: rbd_put_client(rbdc); err_out_args: - if (ceph_opts) - ceph_destroy_options(ceph_opts); - kfree(rbd_opts); rbd_spec_put(spec); err_out_module: module_put(THIS_MODULE);