On Tue, Mar 02, 2021 at 04:14:18AM -0500, Jason Wang wrote:
> When CAP_IPC_LOCK is set we should not check locked memory against
> rlimit as what has been implemented in mlock().
>
> Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx>
Indeed and it's not just mlock.
Documentation/admin-guide/perf-security.rst:
RLIMIT_MEMLOCK and perf_event_mlock_kb resource constraints are ignored
for processes with the CAP_IPC_LOCK capability.
and let's add a Fixes: tag?
> ---
> drivers/vhost/vdpa.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
> index ef688c8c0e0e..e93572e2e344 100644
> --- a/drivers/vhost/vdpa.c
> +++ b/drivers/vhost/vdpa.c
> @@ -638,7 +638,8 @@ static int vhost_vdpa_process_iotlb_update(struct vhost_vdpa *v,
> mmap_read_lock(dev->mm);
>
> lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
> - if (npages + atomic64_read(&dev->mm->pinned_vm) > lock_limit) {
> + if (!capable(CAP_IPC_LOCK) &&
> + (npages + atomic64_read(&dev->mm->pinned_vm) > lock_limit)) {
> ret = -ENOMEM;
> goto unlock;
> }
> --
> 2.18.1
