linux-kernel - Re: [PATCH v5] dma-buf: system_heap: Add a size check for allocation

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <4f2631d3-0845-cae6-6fc0-9c00ce6301ce@amd.com>
Date:   Thu, 20 Jan 2022 09:27:07 +0100
From:   Christian König <christian.koenig@....com>
To:     guangming.cao@...iatek.com, john.stultz@...aro.org
Cc:     benjamin.gaignard@...aro.org, bo.song@...iatek.com,
        caoguangming34@...il.com, dri-devel@...ts.freedesktop.org,
        jianjiao.zeng@...iatek.com, labbott@...hat.com,
        libo.kang@...iatek.com, linaro-mm-sig@...ts.linaro.org,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
        linux-media@...r.kernel.org, linux-mediatek@...ts.infradead.org,
        lmark@...eaurora.org, matthias.bgg@...il.com,
        michael.j.ruhl@...el.com, mingyuan.ma@...iatek.com,
        sumit.semwal@...aro.org, wsd_upstream@...iatek.com,
        yf.wang@...iatek.com
Subject: Re: [PATCH v5] dma-buf: system_heap: Add a size check for allocation



Am 20.01.22 um 08:08 schrieb guangming.cao@...iatek.com:
> From: Guangming <Guangming.Cao@...iatek.com>
>
> Add a size check for allocation since the allocation size should be
> always less than the total DRAM size on system heap.
> Adding this check can prevent comsuming too much time for invalid allocations.
>
> Signed-off-by: Guangming <Guangming.Cao@...iatek.com>
> ---
>   drivers/dma-buf/heaps/system_heap.c | 8 ++++++++
>   1 file changed, 8 insertions(+)
>
> diff --git a/drivers/dma-buf/heaps/system_heap.c b/drivers/dma-buf/heaps/system_heap.c
> index 23a7e74ef966..459dc18bc4a2 100644
> --- a/drivers/dma-buf/heaps/system_heap.c
> +++ b/drivers/dma-buf/heaps/system_heap.c
> @@ -347,6 +347,14 @@ static struct dma_buf *system_heap_allocate(struct dma_heap *heap,
>   	struct page *page, *tmp_page;
>   	int i, ret = -ENOMEM;
>   
> +	/*
> +	 * Size check. The "len" should be less than totalram since system_heap
> +	 * memory is comes from system. Adding check here can prevent comsuming
> +	 * too much time for invalid allocations.
> +	 */
> +	if (len >> PAGE_SHIFT > totalram_pages())

Maybe use PFN_UP() or PFN_DOWN() here instead of open coding this.

Apart from that looks good to me.

Christian.

> +		return ERR_PTR(-EINVAL);
> +
>   	buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
>   	if (!buffer)
>   		return ERR_PTR(-ENOMEM);