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 <[email protected]> Fixes: dc5bdb68b5b3 ("drm/fb-helper: Fix vt restore") Cc: Alex Deucher <[email protected]> Cc: [email protected] Cc: Michel Dänzer <[email protected]> Cc: Noralf Trønnes <[email protected]> Cc: Thomas Zimmermann <[email protected]> Cc: Daniel Vetter <[email protected]> Cc: Maarten Lankhorst <[email protected]> Cc: Maxime Ripard <[email protected]> Cc: David Airlie <[email protected]> Cc: Daniel Vetter <[email protected]> Cc: [email protected] Cc: <[email protected]> # v5.7+ Cc: Bartlomiej Zolnierkiewicz <[email protected]> Cc: Geert Uytterhoeven <[email protected]> Cc: Nathan Chancellor <[email protected]> Cc: Qiujun Huang <[email protected]> Cc: Peter Rosin <[email protected]> Cc: [email protected] Cc: Helge Deller <[email protected]> Cc: Sam Ravnborg <[email protected]> Cc: Geert Uytterhoeven <[email protected]> Cc: Samuel Thibault <[email protected]> Cc: Tetsuo Handa <[email protected]> Cc: Shigeru Yoshida <[email protected]> --- drivers/video/fbdev/core/fbmem.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c index 875541ff185b..3fd95a79e4c3 100644 --- a/drivers/video/fbdev/core/fbmem.c +++ b/drivers/video/fbdev/core/fbmem.c @@ -1116,6 +1116,8 @@ static long do_fb_ioctl(struct fb_info *info, unsigned int cmd, case FBIOPUT_VSCREENINFO: if (copy_from_user(&var, argp, sizeof(var))) return -EFAULT; + /* only for kernel-internal use */ + var.activate &= ~FB_ACTIVATE_KD_TEXT; console_lock(); lock_fb_info(info); ret = fbcon_modechange_possible(info, &var); -- 2.40.0
