Re: [PATCH] aio: add timeout validity check for io_[p]getevents

From: Jeff Moyer <jmoyer@redhat.com>
To: "zhangyi \(F\)" <yi.zhang@huawei.com>
Cc: <linux-aio@kvack.org>, <linux-fsdevel@vger.kernel.org>,
	<linux-kernel@vger.kernel.org>, <bcrl@kvack.org>,
	<viro@zeniv.linux.org.uk>, <wangkefeng.wang@huawei.com>
Subject: Re: [PATCH] aio: add timeout validity check for io_[p]getevents
Date: Thu, 25 Jul 2019 10:43:46 -0400	[thread overview]
Message-ID: <x49imrqb2e5.fsf@segfault.boston.devel.redhat.com> (raw)
In-Reply-To: <1564039289-7672-1-git-send-email-yi.zhang@huawei.com> (zhangyi's message of "Thu, 25 Jul 2019 15:21:29 +0800")

"zhangyi (F)" <yi.zhang@huawei.com> writes:

> io_[p]getevents syscall should return -EINVAL if if timeout is out of
> range, add this validity check.
>
> Signed-off-by: zhangyi (F) <yi.zhang@huawei.com>
> ---
>  fs/aio.c | 11 +++++++++--
>  1 file changed, 9 insertions(+), 2 deletions(-)
>
> diff --git a/fs/aio.c b/fs/aio.c
> index 01e0fb9..dd967a0 100644
> --- a/fs/aio.c
> +++ b/fs/aio.c
> @@ -2031,10 +2031,17 @@ static long do_io_getevents(aio_context_t ctx_id,
>  		struct io_event __user *events,
>  		struct timespec64 *ts)
>  {
> -	ktime_t until = ts ? timespec64_to_ktime(*ts) : KTIME_MAX;
> -	struct kioctx *ioctx = lookup_ioctx(ctx_id);
> +	ktime_t until = KTIME_MAX;
> +	struct kioctx *ioctx = NULL;
>  	long ret = -EINVAL;
>  
> +	if (ts) {
> +		if (!timespec64_valid(ts))
> +			return ret;
> +		until = timespec64_to_ktime(*ts);
> +	}
> +
> +	ioctx = lookup_ioctx(ctx_id);
>  	if (likely(ioctx)) {
>  		if (likely(min_nr <= nr && min_nr >= 0))
>  			ret = read_events(ioctx, min_nr, nr, events, until);

Reviewed-by: Jeff Moyer <jmoyer@redhat.com>

The previous suggestion[1] of fixing the helpers never materialized, so
let's just get this fixed, already.

-Jeff

[1] https://marc.info/?l=linux-fsdevel&m=152209450618587&w=2