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From:   Len Baker <len.baker@gmx.com>
To:     Keith Busch <kbusch@kernel.org>, Jens Axboe <axboe@fb.com>,
        Christoph Hellwig <hch@lst.de>,
        Sagi Grimberg <sagi@grimberg.me>,
        Chaitanya Kulkarni <kch@nvidia.com>
Cc:     Len Baker <len.baker@gmx.com>, Kees Cook <keescook@chromium.org>,
        "Gustavo A. R. Silva" <gustavoars@kernel.org>,
        linux-hardening@vger.kernel.org, linux-nvme@lists.infradead.org,
        linux-kernel@vger.kernel.org
Subject: [PATCH] nvmet: prefer flex_array_size and struct_size over open coded arithmetic
Date:   Sun, 24 Oct 2021 19:29:21 +0200
Message-Id: <20211024172921.4110-1-len.baker@gmx.com>
MIME-Version: 1.0
Content-Transfer-Encoding: quoted-printable
Precedence: bulk

In an effort to avoid open-coded arithmetic in the kernel [1], use the
flex_array_size() and struct_size() helpers instead of an open-coded
calculation.

[1] https://github.com/KSPP/linux/issues/160

Signed-off-by: Len Baker <len.baker@gmx.com>
=2D--
 drivers/nvme/host/multipath.c   | 2 +-
 drivers/nvme/target/admin-cmd.c | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c
index 954e84df6eb7..7f2071f2460c 100644
=2D-- a/drivers/nvme/host/multipath.c
+++ b/drivers/nvme/host/multipath.c
@@ -562,7 +562,7 @@ static int nvme_parse_ana_log(struct nvme_ctrl *ctrl, =
void *data,
 			return -EINVAL;

 		nr_nsids =3D le32_to_cpu(desc->nnsids);
-		nsid_buf_size =3D nr_nsids * sizeof(__le32);
+		nsid_buf_size =3D flex_array_size(desc, nsids, nr_nsids);

 		if (WARN_ON_ONCE(desc->grpid =3D=3D 0))
 			return -EINVAL;
diff --git a/drivers/nvme/target/admin-cmd.c b/drivers/nvme/target/admin-c=
md.c
index 403de678fd06..6fb24746de06 100644
=2D-- a/drivers/nvme/target/admin-cmd.c
+++ b/drivers/nvme/target/admin-cmd.c
@@ -264,7 +264,7 @@ static u32 nvmet_format_ana_group(struct nvmet_req *re=
q, u32 grpid,
 	desc->chgcnt =3D cpu_to_le64(nvmet_ana_chgcnt);
 	desc->state =3D req->port->ana_state[grpid];
 	memset(desc->rsvd17, 0, sizeof(desc->rsvd17));
-	return sizeof(struct nvme_ana_group_desc) + count * sizeof(__le32);
+	return struct_size(desc, nsids, count);
 }

 static void nvmet_execute_get_log_page_ana(struct nvmet_req *req)
=2D-
2.25.1