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| author | Peter Malone <peter.malone@gmail.com> | 2018-03-07 14:00:34 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-05-30 07:50:35 +0200 |
| commit | 05b4268070b14dbd77ac6f5986b77a80a458fffa (patch) | |
| tree | 601944fe16b5974875c88a9644e0d0d79727f24a | |
| parent | d2d48e0161b54be303b8023fd85b4c95ac8b83ca (diff) | |
fbdev: Fixing arbitrary kernel leak in case FBIOGETCMAP_SPARC in sbusfb_ioctl_helper().
[ Upstream commit 250c6c49e3b68756b14983c076183568636e2bde ]
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>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/video/fbdev/sbuslib.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/video/fbdev/sbuslib.c b/drivers/video/fbdev/sbuslib.c index a350209ffbd3..31c301d6be62 100644 --- a/drivers/video/fbdev/sbuslib.c +++ b/drivers/video/fbdev/sbuslib.c @@ -121,7 +121,7 @@ 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) || @@ -160,7 +160,7 @@ 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) || |