This is a note to let you know that I've just added the patch titled
drivers/cdrom/cdrom.c: use kzalloc() for failing hardware
to the 3.9-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:
drivers-cdrom-cdrom.c-use-kzalloc-for-failing-hardware.patch
and it can be found in the queue-3.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 542db01579fbb7ea7d1f7bb9ddcef1559df660b2 Mon Sep 17 00:00:00 2001
From: Jonathan Salwan <jonathan.salwan@xxxxxxxxx>
Date: Wed, 3 Jul 2013 15:01:13 -0700
Subject: drivers/cdrom/cdrom.c: use kzalloc() for failing hardware
From: Jonathan Salwan <jonathan.salwan@xxxxxxxxx>
commit 542db01579fbb7ea7d1f7bb9ddcef1559df660b2 upstream.
In drivers/cdrom/cdrom.c mmc_ioctl_cdrom_read_data() allocates a memory
area with kmalloc in line 2885.
2885 cgc->buffer = kmalloc(blocksize, GFP_KERNEL);
2886 if (cgc->buffer == NULL)
2887 return -ENOMEM;
In line 2908 we can find the copy_to_user function:
2908 if (!ret && copy_to_user(arg, cgc->buffer, blocksize))
The cgc->buffer is never cleaned and initialized before this function.
If ret = 0 with the previous basic block, it's possible to display some
memory bytes in kernel space from userspace.
When we read a block from the disk it normally fills the ->buffer but if
the drive is malfunctioning there is a chance that it would only be
partially filled. The result is an leak information to userspace.
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Cc: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Jonathan Salwan <jonathan.salwan@xxxxxxxxx>
Cc: Luis Henriques <luis.henriques@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/cdrom/cdrom.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/cdrom/cdrom.c
+++ b/drivers/cdrom/cdrom.c
@@ -2882,7 +2882,7 @@ static noinline int mmc_ioctl_cdrom_read
if (lba < 0)
return -EINVAL;
- cgc->buffer = kmalloc(blocksize, GFP_KERNEL);
+ cgc->buffer = kzalloc(blocksize, GFP_KERNEL);
if (cgc->buffer == NULL)
return -ENOMEM;
Patches currently in stable-queue which might be from jonathan.salwan@xxxxxxxxx are
queue-3.9/drivers-cdrom-cdrom.c-use-kzalloc-for-failing-hardware.patch
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