Re: [PATCH v2] net: ethernet: fix NULL dereference in nixge_recv()

On Tue, Dec 17, 2024 at 12:25 PM Ma Ke make_ruc2021@163.com wrote:

Due to the failure of allocating the variable 'priv' in netdev_priv(ndev), this could result in 'priv->rx_bd_v' not being set during the allocation process of netdev_priv(ndev), which could lead to a null pointer dereference.

Move while() loop with 'priv->rx_bd_v' dereference after the check for its validity.

Found by code review.

Cc: stable@vger.kernel.org Fixes: 492caffa8a1a ("net: ethernet: nixge: Add support for National Instruments XGE netdev") Signed-off-by: Ma Ke make_ruc2021@163.com

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Changes in v2:

• modified the bug description as suggestions;
• modified the patch as the code style suggested.

I really do not understand this patch.

if priv->rx_bd_v allocation failed, surely the device is not operational, because nixge_hw_dma_bd_init() returns -ENOMEM