| From d3d19d6fc5736a798b118971935ce274f7deaa82 Mon Sep 17 00:00:00 2001 |
| From: Dan Carpenter <dan.carpenter@oracle.com> |
| Date: Mon, 13 Jan 2020 14:08:14 +0300 |
| Subject: fbdev: potential information leak in do_fb_ioctl() |
| |
| 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.ixpaymordi24n3av@kili.mountain |
| 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 |
| @@ -1134,7 +1134,7 @@ 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; |