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authorPeter Malone <peter.malone@gmail.com>2018-03-07 16:00:34 +0300
committerBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>2018-03-07 16:00:34 +0300
commit250c6c49e3b68756b14983c076183568636e2bde (patch)
tree0a893a4160c4b68a1240e0c6efad154ed7c8bfdb /drivers/video/fbdev/sbuslib.c
parent5fe9cfbe44b6892e17f803125c4761221b0175c6 (diff)
downloadlinux-250c6c49e3b68756b14983c076183568636e2bde.tar.xz
fbdev: Fixing arbitrary kernel leak in case FBIOGETCMAP_SPARC in sbusfb_ioctl_helper().
Fixing arbitrary kernel leak in case FBIOGETCMAP_SPARC in sbusfb_ioctl_helper(). 'index' is defined as an int in sbusfb_ioctl_helper(). We retrieve this from the user: if (get_user(index, &c->index) || __get_user(count, &c->count) || __get_user(ured, &c->red) || __get_user(ugreen, &c->green) || __get_user(ublue, &c->blue)) return -EFAULT; and then we use 'index' in the following way: red = cmap->red[index + i] >> 8; green = cmap->green[index + i] >> 8; blue = cmap->blue[index + i] >> 8; This is a classic information leak vulnerability. 'index' should be an unsigned int, given its usage above. This patch is straight-forward; it changes 'index' to unsigned int in two switch-cases: FBIOGETCMAP_SPARC && FBIOPUTCMAP_SPARC. This patch fixes CVE-2018-6412. Signed-off-by: Peter Malone <peter.malone@gmail.com> Acked-by: Mathieu Malaterre <malat@debian.org> Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Diffstat (limited to 'drivers/video/fbdev/sbuslib.c')
-rw-r--r--drivers/video/fbdev/sbuslib.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/video/fbdev/sbuslib.c b/drivers/video/fbdev/sbuslib.c
index af6fc97f4ba4..a436d44f1b7f 100644
--- a/drivers/video/fbdev/sbuslib.c
+++ b/drivers/video/fbdev/sbuslib.c
@@ -122,7 +122,7 @@ int sbusfb_ioctl_helper(unsigned long cmd, unsigned long arg,
unsigned char __user *ured;
unsigned char __user *ugreen;
unsigned char __user *ublue;
- int index, count, i;
+ unsigned int index, count, i;
if (get_user(index, &c->index) ||
__get_user(count, &c->count) ||
@@ -161,7 +161,7 @@ int sbusfb_ioctl_helper(unsigned long cmd, unsigned long arg,
unsigned char __user *ugreen;
unsigned char __user *ublue;
struct fb_cmap *cmap = &info->cmap;
- int index, count, i;
+ unsigned int index, count, i;
u8 red, green, blue;
if (get_user(index, &c->index) ||