On 2023-04-11 15:44, Daniel Vetter wrote:
On Tue, Apr 04, 2023 at 09:39:34PM +0200, Daniel Vetter wrote:This is an oversight from dc5bdb68b5b3 ("drm/fb-helper: Fix vt restore") - I failed to realize that nasty userspace could set this. It's not pretty to mix up kernel-internal and userspace uapi flags like this, but since the entire fb_var_screeninfo structure is uapi we'd need to either add a new parameter to the ->fb_set_par callback and fb_set_par() function, which has a _lot_ of users. Or some other fairly ugly side-channel int fb_info. Neither is a pretty prospect. Instead just correct the issue at hand by filtering out this kernel-internal flag in the ioctl handling code. Signed-off-by: Daniel Vetter <daniel.vet...@intel.com> Fixes: dc5bdb68b5b3 ("drm/fb-helper: Fix vt restore") Cc: Alex Deucher <alexander.deuc...@amd.com> Cc: shl...@fastmail.com Cc: Michel Dänzer <mic...@daenzer.net> Cc: Noralf Trønnes <nor...@tronnes.org> Cc: Thomas Zimmermann <tzimmerm...@suse.de> Cc: Daniel Vetter <daniel.vet...@intel.com> Cc: Maarten Lankhorst <maarten.lankho...@linux.intel.com> Cc: Maxime Ripard <mrip...@kernel.org> Cc: David Airlie <airl...@linux.ie> Cc: Daniel Vetter <dan...@ffwll.ch> Cc: dri-devel@lists.freedesktop.org Cc: <sta...@vger.kernel.org> # v5.7+ Cc: Bartlomiej Zolnierkiewicz <b.zolnier...@samsung.com> Cc: Geert Uytterhoeven <ge...@linux-m68k.org> Cc: Nathan Chancellor <natechancel...@gmail.com> Cc: Qiujun Huang <hqjag...@gmail.com> Cc: Peter Rosin <p...@axentia.se> Cc: linux-fb...@vger.kernel.org Cc: Helge Deller <del...@gmx.de> Cc: Sam Ravnborg <s...@ravnborg.org> Cc: Geert Uytterhoeven <geert+rene...@glider.be> Cc: Samuel Thibault <samuel.thiba...@ens-lyon.org> Cc: Tetsuo Handa <penguin-ker...@i-love.sakura.ne.jp> Cc: Shigeru Yoshida <syosh...@redhat.com>An Ack on this (or a better idea) would be great, so I can stuff it into -fixes.
Acked-by: Maarten Lankhorst <maarten.lankho...@linux.intel.com>
