Re: [PATCH v3] serial: pch_uart: potential dereference of null pointer

[Greg KH]

On Thu, Dec 16, 2021 at 10:14:54PM +0800, Jiasheng Jiang wrote:
> The return value of dma_alloc_coherent() needs to be checked.
> To avoid dereference of null pointer in case of the failure of alloc.
> Signed-off-by: Jiasheng Jiang <jiasheng@xxxxxxxxxxx>

A blank line is always needed before the signed-off-by line.

> ---
> Changelog:
> 
> v2 -> v3
> 
> *Change 1. Remove dev_err.
> *Change 2. Change the return type of pch_request_dma to int.
> *Change 3. Return -ENOMEM when dma_alloc_coherent() failed and 0 the
> others.
> *Change 4. Check return value of dma_alloc_coherent().

I see v3 here, not v4.  Where is v4?

And how did you test this change?

thanks,

greg k-h