From eac7230fdb4672c2cb56f6a01a1744f562c01f80 Mon Sep 17 00:00:00 2001
From: Lao Wei <zrlw@qq.com>
Date: Mon, 9 Jul 2018 08:15:53 -0400
Subject: [PATCH] media: fix: media: pci: meye: validate offset to avoid arbitrary access
Git-commit: eac7230fdb4672c2cb56f6a01a1744f562c01f80
Patch-mainline: v4.20-rc1
References: bsc#1051510
Motion eye video4linux driver for Sony Vaio PictureBook desn't validate user-controlled parameter
'vma->vm_pgoff', a malicious process might access all of kernel memory from user space by trying
pass different arbitrary address.
Discussion: http://www.openwall.com/lists/oss-security/2018/07/06/1
Signed-off-by: Lao Wei <zrlw@qq.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
drivers/media/pci/meye/meye.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/media/pci/meye/meye.c b/drivers/media/pci/meye/meye.c
index 7285edcdd323..bd870e60c32b 100644
--- a/drivers/media/pci/meye/meye.c
+++ b/drivers/media/pci/meye/meye.c
@@ -1460,7 +1460,7 @@ static int meye_mmap(struct file *file, struct vm_area_struct *vma)
unsigned long page, pos;
mutex_lock(&meye.lock);
- if (size > gbuffers * gbufsize) {
+ if (size > gbuffers * gbufsize || offset > gbuffers * gbufsize - size) {
mutex_unlock(&meye.lock);
return -EINVAL;
}
--
2.16.4