[edk2-devel] [edk2-libc Patch] StdLib/LibC/StdLib: Handle possible math overflow in malloc()

[Rebecca Cran]

Reviewed-by: Rebecca Cran <rebecca at nuviainc.com>


Not sure the first \n is needed though.


-- 

Rebecca Cran


On 8/18/21 4:03 PM, Michael D Kinney wrote:
> REF: https://bugzilla.tianocore.org/show_bug.cgi?id=1510
>
> Check for addition overflow in malloc() when computing NodeSize
> and return error if overflow is detected.
>
> Cc: Rebecca Cran <rebecca at nuviainc.com>
> Cc: Yitzhak Briskman <yitzhak.briskman at intel.com>
> Cc: Jian J Wang <jian.j.wang at intel.com>
> Cc: Yonghong Zhu <yonghong.zhu at intel.com>
> Signed-off-by: Michael D Kinney <michael.d.kinney at intel.com>
> ---
>   StdLib/LibC/StdLib/Malloc.c | 6 ++++++
>   1 file changed, 6 insertions(+)
>
> diff --git a/StdLib/LibC/StdLib/Malloc.c b/StdLib/LibC/StdLib/Malloc.c
> index c131b9e..7bf8827 100644
> --- a/StdLib/LibC/StdLib/Malloc.c
> +++ b/StdLib/LibC/StdLib/Malloc.c
> @@ -94,6 +94,12 @@ malloc(size_t Size)
>       return NULL;
>     }
>   
> +  if ((Size + sizeof(CPOOL_HEAD)) < Size) {
> +    RetVal  = NULL;
> +    errno   = ENOMEM;
> +    DEBUG((DEBUG_ERROR, "\nERROR malloc: Size overflow\n"));
> +  }
> +
>     NodeSize = (UINTN)(Size + sizeof(CPOOL_HEAD));
>   
>     DEBUG((DEBUG_POOL, "malloc(%d): NodeSz: %d", Size, NodeSize));


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