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| author | Emil Velikov <emil.velikov@collabora.com> | 2020-03-19 20:29:29 +0300 |
|---|---|---|
| committer | Emil Velikov <emil.l.velikov@gmail.com> | 2020-03-30 14:20:32 +0300 |
| commit | 45bc3d26c95a8fc63a7d8668ca9e57ef0883351c (patch) | |
| tree | 2b8b7a32df9762d6a9025fd4ab6d9d6f7c920358 /drivers/gpu/drm/drm_ioctl.c | |
| parent | c7ccc1b783681722638ec0c432908f69d197303a (diff) | |
| download | linux-45bc3d26c95a8fc63a7d8668ca9e57ef0883351c.tar.xz | |
drm: rework SET_MASTER and DROP_MASTER perm handling
This commit reworks the permission handling of the two ioctls. In
particular it enforced the CAP_SYS_ADMIN check only, if:
- we're issuing the ioctl from process other than the one which opened
the node, and
- we are, or were master in the past
This ensures that we:
- do not regress the systemd-logind style of DRM_MASTER arbitrator
- allow applications which do not use systemd-logind to drop their
master capabilities (and regain them at later point) ... w/o running as
root.
See the comment above drm_master_check_perm() for more details.
v1:
- Tweak wording, fixup all checks, add igt test
v2:
- Add a few more comments, grammar nitpicks.
Cc: Adam Jackson <ajax@redhat.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Pekka Paalanen <ppaalanen@gmail.com>
Testcase: igt/core_setmaster/master-drop-set-user
Signed-off-by: Emil Velikov <emil.velikov@collabora.com>
Reviewed-by: Adam Jackson <ajax@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200319172930.230583-1-emil.l.velikov@gmail.com
Diffstat (limited to 'drivers/gpu/drm/drm_ioctl.c')
| -rw-r--r-- | drivers/gpu/drm/drm_ioctl.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/gpu/drm/drm_ioctl.c b/drivers/gpu/drm/drm_ioctl.c index 9e41972c4bbc..73e31dd4e442 100644 --- a/drivers/gpu/drm/drm_ioctl.c +++ b/drivers/gpu/drm/drm_ioctl.c @@ -599,8 +599,8 @@ static const struct drm_ioctl_desc drm_ioctls[] = { DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_SET_SAREA_CTX, drm_legacy_setsareactx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_GET_SAREA_CTX, drm_legacy_getsareactx, DRM_AUTH), - DRM_IOCTL_DEF(DRM_IOCTL_SET_MASTER, drm_setmaster_ioctl, DRM_ROOT_ONLY), - DRM_IOCTL_DEF(DRM_IOCTL_DROP_MASTER, drm_dropmaster_ioctl, DRM_ROOT_ONLY), + DRM_IOCTL_DEF(DRM_IOCTL_SET_MASTER, drm_setmaster_ioctl, 0), + DRM_IOCTL_DEF(DRM_IOCTL_DROP_MASTER, drm_dropmaster_ioctl, 0), DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_ADD_CTX, drm_legacy_addctx, DRM_AUTH|DRM_ROOT_ONLY), DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_RM_CTX, drm_legacy_rmctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), |