This is a note to let you know that I've just added the patch titled
fbcon: Fix boundary checks for fbcon=vc:n1-n2 parameters
to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
fbcon-fix-boundary-checks-for-fbcon-vc-n1-n2-parameters.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From cad564ca557f8d3bb3b1fa965d9a2b3f6490ec69 Mon Sep 17 00:00:00 2001
From: Helge Deller <deller@xxxxxx>
Date: Thu, 2 Jun 2022 22:06:28 +0200
Subject: fbcon: Fix boundary checks for fbcon=vc:n1-n2 parameters
From: Helge Deller <deller@xxxxxx>
commit cad564ca557f8d3bb3b1fa965d9a2b3f6490ec69 upstream.
The user may use the fbcon=vc:<n1>-<n2> option to tell fbcon to take
over the given range (n1...n2) of consoles. The value for n1 and n2
needs to be a positive number and up to (MAX_NR_CONSOLES - 1).
The given values were not fully checked against those boundaries yet.
To fix the issue, convert first_fb_vc and last_fb_vc to unsigned
integers and check them against the upper boundary, and make sure that
first_fb_vc is smaller than last_fb_vc.
Cc: stable@xxxxxxxxxxxxxxx # v4.19+
Reviewed-by: Daniel Vetter <daniel.vetter@xxxxxxxx>
Signed-off-by: Helge Deller <deller@xxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/YpkYRMojilrtZIgM@p100
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/video/fbdev/core/fbcon.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
--- a/drivers/video/fbdev/core/fbcon.c
+++ b/drivers/video/fbdev/core/fbcon.c
@@ -123,8 +123,8 @@ static int logo_lines;
enums. */
static int logo_shown = FBCON_LOGO_CANSHOW;
/* console mappings */
-static int first_fb_vc;
-static int last_fb_vc = MAX_NR_CONSOLES - 1;
+static unsigned int first_fb_vc;
+static unsigned int last_fb_vc = MAX_NR_CONSOLES - 1;
static int fbcon_is_default = 1;
static int primary_device = -1;
static int fbcon_has_console_bind;
@@ -474,10 +474,12 @@ static int __init fb_console_setup(char
options += 3;
if (*options)
first_fb_vc = simple_strtoul(options, &options, 10) - 1;
- if (first_fb_vc < 0)
+ if (first_fb_vc >= MAX_NR_CONSOLES)
first_fb_vc = 0;
if (*options++ == '-')
last_fb_vc = simple_strtoul(options, &options, 10) - 1;
+ if (last_fb_vc < first_fb_vc || last_fb_vc >= MAX_NR_CONSOLES)
+ last_fb_vc = MAX_NR_CONSOLES - 1;
fbcon_is_default = 0;
continue;
}
Patches currently in stable-queue which might be from deller@xxxxxx are
queue-5.4/fbcon-fix-boundary-checks-for-fbcon-vc-n1-n2-parameters.patch
