From: Eric Biggers <ebiggers@kernel.org>
To: Jiri Slaby <jslaby@suse.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com,
Al Viro <viro@zeniv.linux.org.uk>
Subject: Re: [PATCH] tty: fix compat TIOCGSERIAL leaking uninitialized memory
Date: Mon, 24 Feb 2020 10:15:32 -0800 [thread overview]
Message-ID: <20200224181532.GA109047@gmail.com> (raw)
In-Reply-To: <1edbbced-58c1-7674-2d01-6a807ddf5968@suse.com>
On Mon, Feb 24, 2020 at 09:47:26AM +0100, Jiri Slaby wrote:
> On 24. 02. 20, 9:38, 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 struct 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.
> >
> > 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>
> > ---
> > drivers/tty/tty_io.c | 1 +
> > 1 file changed, 1 insertion(+)
> >
> > diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
> > index 1fcf7ad83dfa0..d24c250312edf 100644
> > --- a/drivers/tty/tty_io.c
> > +++ b/drivers/tty/tty_io.c
> > @@ -2731,6 +2731,7 @@ static int compat_tty_tiocgserial(struct tty_struct *tty,
> > struct serial_struct v;
> > int err;
> > memset(&v, 0, sizeof(struct serial_struct));
> > + memset(&v32, 0, sizeof(struct serial_struct32));
>
> sizeof(v32) please.
>
Sure, I was trying to be consistent with the other line, but I'll just change
them both to sizeof.
- Eric
next prev parent reply other threads:[~2020-02-24 18:15 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-24 8:18 KMSAN: kernel-infoleak in tty_compat_ioctl syzbot
2020-02-24 8:38 ` [PATCH] tty: fix compat TIOCGSERIAL leaking uninitialized memory Eric Biggers
2020-02-24 8:47 ` Jiri Slaby
2020-02-24 18:15 ` Eric Biggers [this message]
2020-02-24 18:20 ` [PATCH v2 0/2] tty: fix bugs in compat TIOCGSERIAL Eric Biggers
2020-02-24 18:20 ` [PATCH v2 1/2] tty: fix compat TIOCGSERIAL leaking uninitialized memory Eric Biggers
2020-02-25 7:30 ` Jiri Slaby
2020-03-02 21:24 ` Eric Biggers
2020-03-03 6:29 ` Greg Kroah-Hartman
2020-03-18 12:00 ` Greg Kroah-Hartman
2020-03-18 16:36 ` Eric Biggers
2020-02-24 18:20 ` [PATCH v2 2/2] tty: fix compat TIOCGSERIAL checking wrong function ptr Eric Biggers
2020-02-25 7:30 ` Jiri Slaby
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