Messages in this thread | | | Date | Wed, 16 Sep 2020 08:19:49 +0200 | From | Christoph Hellwig <> | Subject | Re: [PATCH] dma-direct: Fix potential NULL pointer dereference |
| |
On Tue, Sep 15, 2020 at 04:46:17PM -0400, Thomas Tai wrote: > I tried out the suggested changes, and it successfully warned the null > pointer without panic. I notice that there are some places outside the > dma-direct, which calls dma_capable(). > > https://elixir.bootlin.com/linux/v5.9-rc5/source/arch/x86/kernel/amd_gart_64.c#L187 > > https://elixir.bootlin.com/linux/v5.9-rc5/source/drivers/xen/swiotlb-xen.c#L387
All of these still come in throught the wrappers in kernel/dma/mapping.c.
> Given that the WARN_ON_ONCE already did the intended warning, would you be > ok that I keep the null checking in dma_capable()?
No, the generic dma mapping layer is the right place.
| |