Re: [PATCH] net: ravb: Fix dma_addr_t truncation in error case

[Sergey Shtylyov]

On 1/13/24 7:22 AM, Nikita Yushchenko wrote:

> In ravb_start_xmit(), ravb driver uses u32 variable to store result of
> dma_map_single() call. Since ravb hardware has 32-bit address fields in
> descriptors, this works properly when mapping is successful - it is
> platform's job to provide mapping addresses that fit into hardware
> limitations.
> 
> However, in failure case dma_map_single() returns DMA_MAPPING_ERROR
> constant that is 64-bit when dma_addr_t is 64-bit. Storing this constant
> in u32 leads to truncation, and further call to dma_mapping_error()
> fails to notice the error.
> 
> Fix that by storing result of dma_map_single() in a dma_addr_t
> variable.
> 
> Fixes: c156633f1353 ("Renesas Ethernet AVB driver proper")
> Signed-off-by: Nikita Yushchenko <nikita.yoush@xxxxxxxxxxxxxxxxxx>

Reviewed-by: Sergey Shtylyov <s.shtylyov@xxxxxx>

[...]

MBR, Sergey