| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.4 143/159] fbdev: sbuslib: integer overflow in sbusfb_ioctl_helper() | Date | Fri, 22 Nov 2019 11:28:54 +0100 |
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From: Dan Carpenter <dan.carpenter@oracle.com>
[ Upstream commit e5017716adb8aa5c01c52386c1b7470101ffe9c5 ]
The "index + count" addition can overflow. Both come directly from the user. This bug leads to an information leak.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Cc: Peter Malone <peter.malone@gmail.com> Cc: Philippe Ombredanne <pombredanne@nexb.com> Cc: Mathieu Malaterre <malat@debian.org> Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Signed-off-by: Sasha Levin <sashal@kernel.org> --- drivers/video/fbdev/sbuslib.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/video/fbdev/sbuslib.c b/drivers/video/fbdev/sbuslib.c index b425718925c01..52e161dbd2047 100644 --- a/drivers/video/fbdev/sbuslib.c +++ b/drivers/video/fbdev/sbuslib.c @@ -170,7 +170,7 @@ int sbusfb_ioctl_helper(unsigned long cmd, unsigned long arg, get_user(ublue, &c->blue)) return -EFAULT; - if (index + count > cmap->len) + if (index > cmap->len || count > cmap->len - index) return -EINVAL; for (i = 0; i < count; i++) { -- 2.20.1
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