[PATCH v2 2/4] nvme: reject invalid pr_read_keys() num_keys values

[Chaitanya Kulkarni]

On 11/27/25 07:54, Stefan Hajnoczi wrote:
> 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.
>
> Signed-off-by: Stefan Hajnoczi<stefanha at redhat.com>
> ---
>   drivers/nvme/host/pr.c | 4 ++++
>   1 file changed, 4 insertions(+)
>
> diff --git a/drivers/nvme/host/pr.c b/drivers/nvme/host/pr.c
> index ca6a74607b139..156a2ae1fac2e 100644
> --- a/drivers/nvme/host/pr.c
> +++ b/drivers/nvme/host/pr.c
> @@ -233,6 +233,10 @@ static int nvme_pr_read_keys(struct block_device *bdev,
>   	int ret, i;
>   	bool eds;
>   
> +	/* Check that keys fit into u32 rse_len */
> +	if (num_keys > (U32_MAX - sizeof(*rse)) / sizeof(rse->regctl_eds[0]))
> +		return -EINVAL;

de-referencing res in res->regctl_eds[0] is safe in this patch ?

if so please ignore this comment ...

-ck