Commit 84909f7d authored by Nilay Shroff's avatar Nilay Shroff Committed by Keith Busch
Browse files

nvmet: use kzalloc instead of ZERO_PAGE in nvme_execute_identify_ns_nvm() 



The nvme_execute_identify_ns_nvm function uses ZERO_PAGE for copying
SG list with all zeros. As ZERO_PAGE would not necessarily return the
virtual-address of the zero page, we need to first convert the page
address to kernel virtual-address and then use it as source address
for copying the data to SG list with all zeros. Using return address
of ZERO_PAGE(0) as source address for copying data to SG list would
fill the target buffer with random/garbage value and causes the
undesired side effect.

As other identify implemenations uses kzalloc for allocating a zero
filled buffer, we decided use kzalloc for allocating a zero filled
buffer in nvme_execute_identify_ns_nvm function and then use this
buffer for copying all zeros to SG list buffers. So esentially, we
now avoid using ZERO_PAGE.

Reported-by: default avatarYi Zhang <yi.zhang@redhat.com>
Fixes: 64a51080 ("nvmet: implement id ns for nvm command set")
Link: https://lore.kernel.org/all/CAHj4cs8OVyxmn4XTvA=y4uQ3qWpdw-x3M3FSUYr-KpE-nhaFEA@mail.gmail.com/


Signed-off-by: default avatarNilay Shroff <nilay@linux.ibm.com>
Tested-by: default avatarYi Zhang <yi.zhang@redhat.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarChaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: default avatarKeith Busch <kbusch@kernel.org>
parent ec9b3ac6

drivers/nvme/target/admin-cmd.c

+7 −2
Original line number Diff line number Diff line
@@ -902,13 +902,18 @@ static void nvmet_execute_identify_ctrl_nvm(struct nvmet_req *req) 
static void nvme_execute_identify_ns_nvm(struct nvmet_req *req)

{

	u16 status;

	struct nvme_id_ns_nvm *id;



	status = nvmet_req_find_ns(req);

	if (status)

		goto out;



	status = nvmet_copy_to_sgl(req, 0, ZERO_PAGE(0),

				   NVME_IDENTIFY_DATA_SIZE);

	id = kzalloc(sizeof(*id), GFP_KERNEL);

	if (!id) {

		status = NVME_SC_INTERNAL;

		goto out;

	}

	status = nvmet_copy_to_sgl(req, 0, id, sizeof(*id));

out:

	nvmet_req_complete(req, status);

}