lkml.org 
[lkml]   [2016]   [Jan]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: int overflow in io_getevents
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);
> }


\
 
 \ /
  Last update: 2016-01-07 17:01    [W:0.062 / U:0.792 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site