linux-kernel - [PATCH 1/2] auxdisplay/cfag12864bfb.c: Convert to use vm_map_pages

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Message-Id: <1558366136-3765-1-git-send-email-jrdr.linux@gmail.com>
Date:   Mon, 20 May 2019 20:58:56 +0530
From:   Souptick Joarder <jrdr.linux@...il.com>
To:     miguel.ojeda.sandonis@...il.com
Cc:     linux-kernel@...r.kernel.org, willy@...radead.org,
        Souptick Joarder <jrdr.linux@...il.com>
Subject: [PATCH 1/2] auxdisplay/cfag12864bfb.c: Convert to use vm_map_pages_zero()

While using mmap, the incorrect value of length and vm_pgoff are
ignored and this driver go ahead with mapping cfag12864b_buffer
to user vma.

Convert vm_insert_pages() to use vm_map_pages_zero(). We could later
"fix" these drivers to behave according to the normal vm_pgoff
offsetting simply by removing the _zero suffix on the function name and
if that causes regressions, it gives us an easy way to revert.

Signed-off-by: Souptick Joarder <jrdr.linux@...il.com>
---
 drivers/auxdisplay/cfag12864bfb.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/auxdisplay/cfag12864bfb.c b/drivers/auxdisplay/cfag12864bfb.c
index 40c8a55..4074886 100644
--- a/drivers/auxdisplay/cfag12864bfb.c
+++ b/drivers/auxdisplay/cfag12864bfb.c
@@ -52,8 +52,9 @@
 
 static int cfag12864bfb_mmap(struct fb_info *info, struct vm_area_struct *vma)
 {
-	return vm_insert_page(vma, vma->vm_start,
-		virt_to_page(cfag12864b_buffer));
+	struct page *pages = virt_to_page(cfag12864b_buffer);
+
+	return vm_map_pages_zero(vma, &pages, 1);
 }
 
 static struct fb_ops cfag12864bfb_ops = {
-- 
1.9.1