nvme: reject invalid pr_read_keys() num_keys values

[ Upstream commit 38ec8469f39e0e96e7dd9b76f05e0f8eb78be681 ]

The pr_read_keys() interface has a u32 num_keys parameter. The NVMe
Reservation Report command has a u32 maximum length. Reject num_keys
values that are too large to fit.

This will become important when pr_read_keys() is exposed to untrusted
userspace via an <linux/pr.h> ioctl.

BUG=b/494186991
TEST=presubmit
RELEASE_NOTE=None

cos-patch: security-moderate
Change-Id: I0a211d92ef162906d5ff9c65962501fb900fb17e
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Stable-dep-of: c3320153769f ("nvme: fix memory allocation in nvme_pr_read_keys()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: chenglongtang <chenglongtang@google.com>
Reviewed-on: https://cos-review.googlesource.com/c/third_party/kernel/+/143886
Tested-by: Cusky Presubmit Bot <presubmit@cos-infra-prod.iam.gserviceaccount.com>
Reviewed-by: Kevin Berry <kpberry@google.com>