From: Dan Carpenter dan.carpenter@oracle.com
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@oracle.com Cc: Andrew Morton akpm@linux-foundation.org Cc: Arnd Bergmann arnd@arndb.de Cc: "Eric W. Biederman" ebiederm@xmission.com Cc: Andrea Righi righi.andrea@gmail.com Cc: Daniel Vetter daniel.vetter@ffwll.ch Cc: Sam Ravnborg sam@ravnborg.org Cc: Maarten Lankhorst maarten.lankhorst@linux.intel.com Cc: Daniel Thompson daniel.thompson@linaro.org Cc: Peter Rosin peda@axentia.se Cc: Jani Nikula jani.nikula@intel.com Cc: Gerd Hoffmann kraxel@redhat.com Signed-off-by: Bartlomiej Zolnierkiewicz b.zolnierkie@samsung.com Link: https://patchwork.freedesktop.org/patch/msgid/20200113100132.ixpaymordi24n3a... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- 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 @@ -1122,7 +1122,7 @@ static long do_fb_ioctl(struct fb_info * case FBIOGET_FSCREENINFO: if (!lock_fb_info(info)) return -ENODEV; - fix = info->fix; + memcpy(&fix, &info->fix, sizeof(fix)); unlock_fb_info(info);
ret = copy_to_user(argp, &fix, sizeof(fix)) ? -EFAULT : 0;