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Subject: Re: [PATCH] md/bitmap: check input value with ULONG_MAX in
 timeout_store
To:     linan666@huaweicloud.com, song@kernel.org
Cc:     linux-raid@vger.kernel.org, linux-kernel@vger.kernel.org,
        linan122@huawei.com, yi.zhang@huawei.com, houtao1@huawei.com,
        yangerkun@huawei.com, "yukuai (C)" <yukuai3@huawei.com>
References: <20230527101851.3266500-1-linan666@huaweicloud.com>
From:   Yu Kuai <yukuai1@huaweicloud.com>
Message-ID: <3a1d4ad3-3f85-4ccb-130a-ba3b58d7eeb4@huaweicloud.com>
Date:   Sun, 28 May 2023 15:48:07 +0800
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Hi,

?? 2023/05/27 18:18, linan666@huaweicloud.com д??:
> From: Li Nan <linan122@huawei.com>
> 
> The type of timeout is unsigned long, but it is compared with 'LONG_MAX'
> in timeout_store(), which lead to value within (LONG_MAX, ULONG_MAX.]/HZ
> can't be set. Fix it by checking input value with ULONG_MAX.
> 

nak, because MAX_SCHEDULE_TIMEOUT is LONG_MAX, and LONG_MAX should be
enough for real use case.

Thanks,
Kuai
> Signed-off-by: Li Nan <linan122@huawei.com>
> ---
>   drivers/md/md-bitmap.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/md/md-bitmap.c b/drivers/md/md-bitmap.c
> index bc8d7565171d..5fd9cba65be8 100644
> --- a/drivers/md/md-bitmap.c
> +++ b/drivers/md/md-bitmap.c
> @@ -2460,7 +2460,7 @@ timeout_store(struct mddev *mddev, const char *buf, size_t len)
>   		return rv;
>   
>   	/* just to make sure we don't overflow... */
> -	if (timeout >= LONG_MAX / HZ)
> +	if (timeout >= ULONG_MAX / HZ)
>   		return -EINVAL;
>   
>   	timeout = timeout * HZ / 10000;
>