nvme/lightnvm: Prevent small buffer overflow in nvme_nvm_identify

There are two closely named structs in lightnvm:
struct nvme_nvm_addr_format and
struct nvme_addr_format.

The first struct has 4 reserved bytes at the end, the second does not.
(gdb) p sizeof(struct nvme_nvm_addr_format)
$1 = 16
(gdb) p sizeof(struct nvm_addr_format)
$2 = 12

In the nvme_nvm_identify function we memcpy from the larger struct to the
smaller struct. We incorrectly pass the length of the larger struct
and overflow by 4 bytes, lets not do that.

Signed-off-by: Scott Bauer <scott.bauer@intel.com>
Signed-off-by: Matias Bjørling <matias@cnexlabs.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

diff --git a/drivers/nvme/host/lightnvm.c b/drivers/nvme/host/lightnvm.c
index 21cac8523bd8e335434ba4bdf73c61e8cdb34f9d..fd9895423f55ad3327a76add4a92c525318c926e 100644 (file)
--- a/drivers/nvme/host/lightnvm.c
+++ b/drivers/nvme/host/lightnvm.c
@@ -324,7 +324,7 @@ static int nvme_nvm_identity(struct nvm_dev *nvmdev, struct nvm_id *nvm_id)
        nvm_id->cap = le32_to_cpu(nvme_nvm_id->cap);
        nvm_id->dom = le32_to_cpu(nvme_nvm_id->dom);
        memcpy(&nvm_id->ppaf, &nvme_nvm_id->ppaf,
-                                       sizeof(struct nvme_nvm_addr_format));
+                                       sizeof(struct nvm_addr_format));
 
        ret = init_grps(nvm_id, nvme_nvm_id);
 out: