On September 01, 2020 5:12 PM, Laszlo Ersek wrote:
> The DxeImageVerificationHandler() function currently checks whether
> "SecDataDir" has enough room for "WinCertificate->dwLength". However,
> for advancing "OffSet", "WinCertificate->dwLength" is aligned to the next
> multiple of 8. If "WinCertificate->dwLength" is large enough, the alignment
> will return 0, and "OffSet" will be stuck at the same value.
>
> Check whether "SecDataDir" has room left for both "WinCertificate-
> >dwLength" and the alignment.
>
> Cc: Jian J Wang <jian.j.w...@intel.com>
> Cc: Jiewen Yao <jiewen....@intel.com>
> Cc: Min Xu <min.m...@intel.com>
> Cc: Wenyi Xie <xiewen...@huawei.com>
> Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=2215
> Signed-off-by: Laszlo Ersek <ler...@redhat.com>
Reviewed-by: Min M Xu <min.m...@intel.com>
> ---
> SecurityPkg/Library/DxeImageVerificationLib/DxeImageVerificationLib.c | 4
> +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git
> a/SecurityPkg/Library/DxeImageVerificationLib/DxeImageVerificationLib.c
> b/SecurityPkg/Library/DxeImageVerificationLib/DxeImageVerificationLib.c
> index 100739eb3eb6..11154b6cc58a 100644
> --- a/SecurityPkg/Library/DxeImageVerificationLib/DxeImageVerificationLib.c
> +++ b/SecurityPkg/Library/DxeImageVerificationLib/DxeImageVerificationLi
> +++ b.c
> @@ -1860,7 +1860,9 @@ DxeImageVerificationHandler (
> break;
> }
> WinCertificate = (WIN_CERTIFICATE *) (mImageBase + OffSet);
> - if (SecDataDirLeft < WinCertificate->dwLength) {
> + if (SecDataDirLeft < WinCertificate->dwLength ||
> + (SecDataDirLeft - WinCertificate->dwLength <
> + ALIGN_SIZE (WinCertificate->dwLength))) {
> break;
> }
>
> --
> 2.19.1.3.g30247aa5d201
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