linux-stable/drivers/cdrom
Jonathan Salwan 542db01579 drivers/cdrom/cdrom.c: use kzalloc() for failing hardware
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@oracle.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03 16:07:25 -07:00
..
cdrom.c drivers/cdrom/cdrom.c: use kzalloc() for failing hardware 2013-07-03 16:07:25 -07:00
gdrom.c drivers/cdrom/gdrom.c: fix device number leak 2013-07-03 16:07:25 -07:00
Makefile cdrom: Add support for Sega Dreamcast GD-ROM. 2008-01-28 13:19:04 +09:00