Hi folks,
CVE-2018-6412 has been created for this. Is it possible for you to add a note indicating the CVE number when merging the patch?
I received the CVE number after the patch was created and ack'd, which is why I didn't include it in the commit message.
On Jan 31, 2018 10:49, "Mathieu Malaterre" malat@debian.org wrote:
Hi Peter,
On Wed, Jan 31, 2018 at 3:57 PM, Peter Malone peter.malone@gmail.com wrote:
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.
Signed-off-by: Peter Malone peter.malone@gmail.com
much better :)
v2: fixed formatting
drivers/video/fbdev/sbuslib.c | 4 ++-- 1 file 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) ||-- 2.14.3
By just looking at the code and commit message:
Acked-by: Mathieu Malaterre malat@debian.org