[PATCH AUTOSEL 5.3 15/71] rbd: fix response length parameter for encoded strings

Sasha Levin
2019-10-01T16:39:49Z

From: Dongsheng Yang <dongsheng.yang@easystack.cn>

[ 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@easystack.cn>
Reviewed-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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);
--
2.20.1