2020-03-18 07:54:34

by Qiujun Huang

Subject: [PATCH v2] drm/lease: fix WARNING in idr_destroy

drm_lease_create takes ownership of leases. And leases will be released
by drm_master_put.

drm_master_put
->drm_master_destroy
->idr_destroy

So we needn't call idr_destroy again.

Reported-and-tested-by: [email protected]
Signed-off-by: Qiujun Huang <[email protected]>
---
drivers/gpu/drm/drm_lease.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/drm_lease.c b/drivers/gpu/drm/drm_lease.c
index b481caf..825abe3 100644
--- a/drivers/gpu/drm/drm_lease.c
+++ b/drivers/gpu/drm/drm_lease.c
@@ -542,10 +542,12 @@ int drm_mode_create_lease_ioctl(struct drm_device *dev,
}

DRM_DEBUG_LEASE("Creating lease\n");
+ /* lessee will take the ownership of leases */
lessee = drm_lease_create(lessor, &leases);

if (IS_ERR(lessee)) {
ret = PTR_ERR(lessee);
+ idr_destroy(&leases);
goto out_leases;
}

@@ -580,7 +582,6 @@ int drm_mode_create_lease_ioctl(struct drm_device *dev,

out_leases:
put_unused_fd(fd);
- idr_destroy(&leases);

DRM_DEBUG_LEASE("drm_mode_create_lease_ioctl failed: %d\n", ret);
return ret;
--
1.8.3.1

2020-03-18 13:40:10

by Daniel Vetter

Subject: Re: [PATCH v2] drm/lease: fix WARNING in idr_destroy

On Wed, Mar 18, 2020 at 03:53:50PM +0800, Qiujun Huang wrote:
> drm_lease_create takes ownership of leases. And leases will be released
> by drm_master_put.
>
> drm_master_put
> ->drm_master_destroy
> ->idr_destroy
>
> So we needn't call idr_destroy again.
>
> Reported-and-tested-by: [email protected]
> Signed-off-by: Qiujun Huang <[email protected]>

Thanks for the respin, and I've also seen the syzbot confirmation, so all
great.

Merged to -fixes with a cc: stable.
-Daniel

> ---
> drivers/gpu/drm/drm_lease.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/drm_lease.c b/drivers/gpu/drm/drm_lease.c
> index b481caf..825abe3 100644
> --- a/drivers/gpu/drm/drm_lease.c
> +++ b/drivers/gpu/drm/drm_lease.c
> @@ -542,10 +542,12 @@ int drm_mode_create_lease_ioctl(struct drm_device *dev,
> }
>
> DRM_DEBUG_LEASE("Creating lease\n");
> + /* lessee will take the ownership of leases */
> lessee = drm_lease_create(lessor, &leases);
>
> if (IS_ERR(lessee)) {
> ret = PTR_ERR(lessee);
> + idr_destroy(&leases);
> goto out_leases;
> }
>
> @@ -580,7 +582,6 @@ int drm_mode_create_lease_ioctl(struct drm_device *dev,
>
> out_leases:
> put_unused_fd(fd);
> - idr_destroy(&leases);
>
> DRM_DEBUG_LEASE("drm_mode_create_lease_ioctl failed: %d\n", ret);
> return ret;
> --
> 1.8.3.1
>

--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch