Xiaohui Zhang wrote:

> From: Zhang Xiaohui <ruc_zhangxiao...@163.com>
> 
> If the hardware receives an oversized packet with too many rx fragments,
> skb_shinfo(skb)->frags can overflow and corrupt memory of adjacent pages.
> This becomes especially visible if it corrupts the freelist pointer of
> a slab page.
> 
> Signed-off-by: Zhang Xiaohui <ruc_zhangxiao...@163.com>

Hi, thanks for your patch.

It appears this is a part of a series of patches (at least this one and
one to the ice driver) - please send as one series, with a cover letter
explanation.

Please justify how this is a bug and how this is found / reproduced.

I'll respond separately to the ice driver patch as I don't know this
hardware and it's limits, but I suspect that you've tried to fix a bug
where there was none. (It seems like something a code scanner might find
and be confused about)

> ---
>  drivers/net/ethernet/pensando/ionic/ionic_txrx.c | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/ethernet/pensando/ionic/ionic_txrx.c 
> b/drivers/net/ethernet/pensando/ionic/ionic_txrx.c
> index 169ac4f54..a3e274c65 100644
> --- a/drivers/net/ethernet/pensando/ionic/ionic_txrx.c
> +++ b/drivers/net/ethernet/pensando/ionic/ionic_txrx.c
> @@ -102,8 +102,12 @@ static struct sk_buff *ionic_rx_frags(struct ionic_queue 
> *q,
>  
>               dma_unmap_page(dev, dma_unmap_addr(page_info, dma_addr),
>                              PAGE_SIZE, DMA_FROM_DEVICE);
> -             skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags,
> +             struct skb_shared_info *shinfo = skb_shinfo(skb);

you can't declare variables in the middle of a code flow in C, did you
compile this?

> +
> +             if (shinfo->nr_frags < ARRAY_SIZE(shinfo->frags)) {
> +                     skb_add_rx_frag(skb, shinfo->nr_frags,
>                               page_info->page, 0, frag_len, PAGE_SIZE);
> +             }
>               page_info->page = NULL;
>               page_info++;
>               i--;


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