Re: [PATCH] softmmu/memory: Validate {read, write}_with_attrs before calling

[Philippe Mathieu-Daudé]

Cc'ing PJP for https://www.mail-archive.com/qemu-devel@nongnu.org/msg730311.html

On Sun, Sep 5, 2021 at 5:41 PM Bin Meng <bmeng.cn@gmail.com> wrote:
>
> {read,write}_with_attrs might be missing, and the codes currently do
> not validate them before calling, which will cause segment fault.
>
> Fixes: 62a0db942dec ("memory: Remove old_mmio accessors")
> Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
> ---
>
>  softmmu/memory.c | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/softmmu/memory.c b/softmmu/memory.c
> index bfedaf9c4d..b97ffd4ba7 100644
> --- a/softmmu/memory.c
> +++ b/softmmu/memory.c
> @@ -1426,12 +1426,14 @@ static MemTxResult 
> memory_region_dispatch_read1(MemoryRegion *mr,
>                                           mr->ops->impl.max_access_size,
>                                           memory_region_read_accessor,
>                                           mr, attrs);
> -    } else {
> +    } else if (mr->ops->read_with_attrs) {
>          return access_with_adjusted_size(addr, pval, size,
>                                           mr->ops->impl.min_access_size,
>                                           mr->ops->impl.max_access_size,
>                                           
> memory_region_read_with_attrs_accessor,
>                                           mr, attrs);
> +    } else {
> +        return MEMTX_ERROR;
>      }
>  }
>
> @@ -1506,13 +1508,15 @@ MemTxResult memory_region_dispatch_write(MemoryRegion 
> *mr,
>                                           mr->ops->impl.max_access_size,
>                                           memory_region_write_accessor, mr,
>                                           attrs);
> -    } else {
> +    } else if (mr->ops->write_with_attrs) {
>          return
>              access_with_adjusted_size(addr, &data, size,
>                                        mr->ops->impl.min_access_size,
>                                        mr->ops->impl.max_access_size,
>                                        
> memory_region_write_with_attrs_accessor,
>                                        mr, attrs);
> +    } else {
> +        return MEMTX_ERROR;
>      }
>  }
>
> --
> 2.25.1
>