From: Dan Carpenter <dan.carpenter@xxxxxxxxxx> commit d3d19d6fc5736a798b118971935ce274f7deaa82 upstream. The "fix" struct has a 2 byte hole after ->ywrapstep and the "fix = info->fix;" assignment doesn't necessarily clear it. It depends on the compiler. The solution is just to replace the assignment with an memcpy(). Fixes: 1f5e31d7e55a ("fbmem: don't call copy_from/to_user() with mutex held") Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Cc: Arnd Bergmann <arnd@xxxxxxxx> Cc: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx> Cc: Andrea Righi <righi.andrea@xxxxxxxxx> Cc: Daniel Vetter <daniel.vetter@xxxxxxxx> Cc: Sam Ravnborg <sam@xxxxxxxxxxxx> Cc: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx> Cc: Daniel Thompson <daniel.thompson@xxxxxxxxxx> Cc: Peter Rosin <peda@xxxxxxxxxx> Cc: Jani Nikula <jani.nikula@xxxxxxxxx> Cc: Gerd Hoffmann <kraxel@xxxxxxxxxx> Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@xxxxxxxxxxx> Link: https://patchwork.freedesktop.org/patch/msgid/20200113100132.ixpaymordi24n3av@kili.mountain Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/video/fbdev/core/fbmem.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/video/fbdev/core/fbmem.c +++ b/drivers/video/fbdev/core/fbmem.c @@ -1115,7 +1115,7 @@ static long do_fb_ioctl(struct fb_info * break; case FBIOGET_FSCREENINFO: lock_fb_info(info); - fix = info->fix; + memcpy(&fix, &info->fix, sizeof(fix)); if (info->flags & FBINFO_HIDE_SMEM_START) fix.smem_start = 0; unlock_fb_info(info);