Jonathan Salwan 3e6778af21 drivers/cdrom/cdrom.c: use kzalloc() for failing hardware ... commit 542db01579 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@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> Cc: Jonathan Salwan <jonathan.salwan@gmail.com> Cc: Luis Henriques <luis.henriques@canonical.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2013-07-13 11:03:40 -07:00
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cdrom.c	drivers/cdrom/cdrom.c: use kzalloc() for failing hardware	2013-07-13 11:03:40 -07:00
gdrom.c	block: unexport DISK_EVENT_MEDIA_CHANGE for legacy/fringe drivers	2011-04-21 21:33:05 +02:00
Makefile	cdrom: Add support for Sega Dreamcast GD-ROM.	2008-01-28 13:19:04 +09:00