lkml.org 
[lkml]   [2020]   [Feb]   [25]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH v2 1/2] tty: fix compat TIOCGSERIAL leaking uninitialized memory
From
Date
On 24. 02. 20, 19:20, Eric Biggers wrote:
> From: Eric Biggers <ebiggers@google.com>
>
> Commit 77654350306a ("take compat TIOC[SG]SERIAL treatment into
> tty_compat_ioctl()") changed the compat version of TIOCGSERIAL to start
> copying a whole 'serial_struct32' to userspace rather than individual
> fields, but failed to initialize all padding and fields -- namely the
> hole after the 'iomem_reg_shift' field, and the 'reserved' field.
>
> Fix this by initializing the struct to zero.
>
> [v2: use sizeof, and convert the adjacent line for consistency.]
>
> Reported-by: syzbot+8da9175e28eadcb203ce@syzkaller.appspotmail.com
> Fixes: 77654350306a ("take compat TIOC[SG]SERIAL treatment into tty_compat_ioctl()")
> Cc: <stable@vger.kernel.org> # v4.20+
> Signed-off-by: Eric Biggers <ebiggers@google.com>

Acked-by: Jiri Slaby <jslaby@suse.cz>

> ---
> drivers/tty/tty_io.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
> index 1fcf7ad83dfa0a..db4a13bc855ed6 100644
> --- a/drivers/tty/tty_io.c
> +++ b/drivers/tty/tty_io.c
> @@ -2730,7 +2730,9 @@ static int compat_tty_tiocgserial(struct tty_struct *tty,
> struct serial_struct32 v32;
> struct serial_struct v;
> int err;
> - memset(&v, 0, sizeof(struct serial_struct));
> +
> + memset(&v, 0, sizeof(v));
> + memset(&v32, 0, sizeof(v32));
>
> if (!tty->ops->set_serial)
> return -ENOTTY;
>


--
js
suse labs

\
 
 \ /
  Last update: 2020-02-25 08:30    [W:0.073 / U:0.264 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site