From: Dmitry Vyukov <dvyukov@google.com>
To: Benjamin LaHaise <bcrl@kvack.org>
Cc: Jan Kara <jack@suse.cz>, Alexander Viro <viro@zeniv.linux.org.uk>,
linux-aio <linux-aio@kvack.org>,
"linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
syzkaller <syzkaller@googlegroups.com>,
Kostya Serebryany <kcc@google.com>,
Alexander Potapenko <glider@google.com>,
Sasha Levin <sasha.levin@oracle.com>,
Andrey Ryabinin <ryabinin.a.a@gmail.com>
Subject: Re: int overflow in io_getevents
Date: Thu, 7 Jan 2016 16:37:43 +0100 [thread overview]
Message-ID: <CACT4Y+bD6NXGf6Ry+9rP5mKWbQ1sWb2O-+8HuyRmiK+-gVJTtg@mail.gmail.com> (raw)
In-Reply-To: <20160107153132.GL4439@kvack.org>
On Thu, Jan 7, 2016 at 4:31 PM, Benjamin LaHaise <bcrl@kvack.org> wrote:
> On Thu, Jan 07, 2016 at 10:12:02AM +0100, Dmitry Vyukov wrote:
> ...
>> Sorry, but the following program still prints -9223372036562067969. I
>> think timespec_valid check will do.
>
> Ah, right. Yes, using timespec_valid() instead of timespec_valid_strict()
> as initially proposed will address my concerns. Updated commit below.
>
> -ben
> --
> "Thought is the essence of where you are now."
>
> commit 3a55c535cf3836257434518bd6bc11464c493492
> Author: Benjamin LaHaise <bcrl@kvack.org>
> Date: Thu Jan 7 10:25:44 2016 -0500
>
> aio: handle integer overflow in io_getevents() timespec usage
>
> Dmitry Vyukov reported an integer overflow in io_getevents() when
> running a fuzzer. Upon investigation, the triggers appears to be that
> an invalid value for the tv_sec or tv_nsec was passed in which is not
> handled by timespec_to_ktime(). This patch fixes that by making
> io_getevents() return -EINVAL when timespec_valid() checks fail. We
> use timespec_valid() instead of timespec_valid_strict() to avoid issues
> caused by userspace not knowing the cutoff for KTIME_SEC_MAX.
>
> Reported-by: Dmitry Vyukov <dvyukov@google.com>
> Signed-off-by: Benjamin LaHaise <bcrl@kvack.org>
>
> diff --git a/fs/aio.c b/fs/aio.c
> index 155f842..d161a2f 100644
> --- a/fs/aio.c
> +++ b/fs/aio.c
> @@ -1269,6 +1269,8 @@ static long read_events(struct kioctx *ctx, long min_nr, long nr,
>
> if (unlikely(copy_from_user(&ts, timeout, sizeof(ts))))
> return -EFAULT;
> + if (!timespec_valid())
pass ts to the function
> + return -EINVAL;
>
> until = timespec_to_ktime(ts);
> }
next prev parent reply other threads:[~2016-01-07 15:38 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-12-07 10:27 int overflow in io_getevents Dmitry Vyukov
2015-12-16 12:56 ` Jan Kara
2015-12-16 18:38 ` Dmitry Vyukov
2015-12-18 8:15 ` Jan Kara
2016-01-06 18:01 ` Benjamin LaHaise
2016-01-07 9:12 ` Dmitry Vyukov
2016-01-07 15:31 ` Benjamin LaHaise
2016-01-07 15:37 ` Dmitry Vyukov [this message]
2016-01-07 15:52 ` Benjamin LaHaise
2016-01-07 16:27 ` Dmitry Vyukov
2016-10-26 11:44 ` Jiri Slaby
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