On Tue, Oct 1, 2019 at 6:39 PM Sasha Levin <sashal@xxxxxxxxxx> wrote: > > From: Dongsheng Yang <dongsheng.yang@xxxxxxxxxxxx> > > [ Upstream commit 5435d2069503e2aa89c34a94154f4f2fa4a0c9c4 ] > > rbd_dev_image_id() allocates space for length but passes a smaller > value to rbd_obj_method_sync(). rbd_dev_v2_object_prefix() doesn't > allocate space for length. Fix both to be consistent. > > Signed-off-by: Dongsheng Yang <dongsheng.yang@xxxxxxxxxxxx> > Reviewed-by: Ilya Dryomov <idryomov@xxxxxxxxx> > Signed-off-by: Ilya Dryomov <idryomov@xxxxxxxxx> > Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> > --- > drivers/block/rbd.c | 10 ++++++---- > 1 file changed, 6 insertions(+), 4 deletions(-) > > diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c > index c8fb886aebd4e..69db7385c8df5 100644 > --- a/drivers/block/rbd.c > +++ b/drivers/block/rbd.c > @@ -5669,17 +5669,20 @@ static int rbd_dev_v2_image_size(struct rbd_device *rbd_dev) > > static int rbd_dev_v2_object_prefix(struct rbd_device *rbd_dev) > { > + size_t size; > void *reply_buf; > int ret; > void *p; > > - reply_buf = kzalloc(RBD_OBJ_PREFIX_LEN_MAX, GFP_KERNEL); > + /* Response will be an encoded string, which includes a length */ > + size = sizeof(__le32) + RBD_OBJ_PREFIX_LEN_MAX; > + reply_buf = kzalloc(size, GFP_KERNEL); > if (!reply_buf) > return -ENOMEM; > > ret = rbd_obj_method_sync(rbd_dev, &rbd_dev->header_oid, > &rbd_dev->header_oloc, "get_object_prefix", > - NULL, 0, reply_buf, RBD_OBJ_PREFIX_LEN_MAX); > + NULL, 0, reply_buf, size); > dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret); > if (ret < 0) > goto out; > @@ -6696,7 +6699,6 @@ static int rbd_dev_image_id(struct rbd_device *rbd_dev) > dout("rbd id object name is %s\n", oid.name); > > /* Response will be an encoded string, which includes a length */ > - > size = sizeof (__le32) + RBD_IMAGE_ID_LEN_MAX; > response = kzalloc(size, GFP_NOIO); > if (!response) { > @@ -6708,7 +6710,7 @@ static int rbd_dev_image_id(struct rbd_device *rbd_dev) > > ret = rbd_obj_method_sync(rbd_dev, &oid, &rbd_dev->header_oloc, > "get_id", NULL, 0, > - response, RBD_IMAGE_ID_LEN_MAX); > + response, size); > dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret); > if (ret == -ENOENT) { > image_id = kstrdup("", GFP_KERNEL); Hi Sasha, This patch just made things consistent, there was no bug here. I don't think it should be backported. Thanks, Ilya