Re: [PATCH] MdePkg/BasePeCoffLib: skip runtime relocation if relocation info is invalid.

["Hsueh, Hong-chihX" <hong-chihx.hsueh@intel.com>]

Hi Laszlo & Dandan,
Here is the updated patch for your review. Thank you!
https://lists.01.org/pipermail/edk2-devel/2019-January/035954.html

Regards,
Neo

> -----Original Message-----
> From: Laszlo Ersek [mailto:lersek@redhat.com]
> Sent: Tuesday, January 29, 2019 2:57 AM
> To: Hsueh, Hong-chihX <hong-chihx.hsueh@intel.com>; edk2-devel@lists.01.org
> Cc: Kinney, Michael D <michael.d.kinney@intel.com>; Gao, Liming
> <liming.gao@intel.com>; Bi, Dandan <dandan.bi@intel.com>
> Subject: Re: [PATCH] MdePkg/BasePeCoffLib: skip runtime relocation if
> relocation info is invalid.
> 
> On 01/29/19 00:22, Neo Hsueh wrote:
> > Skip runtime relocation for PE images that provide invalid relocation
> > infomation
> > (ex: RelocDir->Size = 0) to fix a hang observed while booting Windows.
> >
> > Contributed-under: TianoCore Contribution Agreement 1.1
> >
> > Signed-off-by: Neo Hsueh <hong-chihx.hsueh@intel.com>
> > Cc: Michael D Kinney <michael.d.kinney@intel.com>
> > Cc: Liming Gao <liming.gao@intel.com>
> > Cc: Dandan Bi <dandan.bi@intel.com>
> > Cc: Laszlo Ersek <lersek@redhat.com>
> > ---
> >  MdePkg/Library/BasePeCoffLib/BasePeCoff.c | 16 +++++++++++-----
> >  1 file changed, 11 insertions(+), 5 deletions(-)
> >
> > diff --git a/MdePkg/Library/BasePeCoffLib/BasePeCoff.c
> > b/MdePkg/Library/BasePeCoffLib/BasePeCoff.c
> > index 1bd079ad6a..6d6c37bd61 100644
> > --- a/MdePkg/Library/BasePeCoffLib/BasePeCoff.c
> > +++ b/MdePkg/Library/BasePeCoffLib/BasePeCoff.c
> > @@ -1002,7 +1002,7 @@ PeCoffLoaderRelocateImage (
> >                                                                              RelocDir->VirtualAddress +
> RelocDir->Size - 1,
> >                                                                              TeStrippedOffset
> >                                                                              );
> > -    if (RelocBase == NULL || RelocBaseEnd == NULL || RelocBaseEnd <
> RelocBase) {
> > +    if (RelocBase == NULL || RelocBaseEnd == NULL || (UINTN)
> > + RelocBaseEnd < (UINTN) RelocBase) {
> >        ImageContext->ImageError = IMAGE_ERROR_FAILED_RELOCATION;
> >        return RETURN_LOAD_ERROR;
> >      }
> > @@ -1022,7 +1022,7 @@ PeCoffLoaderRelocateImage (
> >      // Run the relocation information and apply the fixups
> >      //
> >      FixupData = ImageContext->FixupData;
> > -    while (RelocBase < RelocBaseEnd) {
> > +    while ((UINTN) RelocBase < (UINTN) RelocBaseEnd) {
> >
> >        Reloc     = (UINT16 *) ((CHAR8 *) RelocBase + sizeof
> (EFI_IMAGE_BASE_RELOCATION));
> >        //
> > @@ -1051,7 +1051,7 @@ PeCoffLoaderRelocateImage (
> >        //
> >        // Run this relocation record
> >        //
> > -      while (Reloc < RelocEnd) {
> > +      while ((UINTN) Reloc < (UINTN) RelocEnd) {
> >          Fixup = PeCoffLoaderImageAddress (ImageContext, RelocBase-
> >VirtualAddress + (*Reloc & 0xFFF), TeStrippedOffset);
> >          if (Fixup == NULL) {
> >            ImageContext->ImageError = IMAGE_ERROR_FAILED_RELOCATION;
> > @@ -1746,6 +1746,12 @@ PeCoffLoaderRelocateImageForRuntime (
> >                                                                              RelocDir->VirtualAddress +
> RelocDir->Size - 1,
> >                                                                              0
> >
> > );
> > +    if (RelocBase == NULL || RelocBaseEnd == NULL || (UINTN) RelocBaseEnd
> < (UINTN) RelocBase) {
> > +      //
> > +      // relocation block is not valid, just return
> > +      //
> > +      return;
> > +    }
> >    } else {
> >      //
> >      // Cannot find relocations, cannot continue to relocate the image, ASSERT
> for this invalid image.
> > @@ -1769,7 +1775,7 @@ PeCoffLoaderRelocateImageForRuntime (
> >      //
> >      FixupData = RelocationData;
> >      RelocBaseOrig = RelocBase;
> > -    while (RelocBase < RelocBaseEnd) {
> > +    while ((UINTN) RelocBase < (UINTN) RelocBaseEnd) {
> >        //
> >        // Add check for RelocBase->SizeOfBlock field.
> >        //
> > @@ -1794,7 +1800,7 @@ PeCoffLoaderRelocateImageForRuntime (
> >        //
> >        // Run this relocation record
> >        //
> > -      while (Reloc < RelocEnd) {
> > +      while ((UINTN) Reloc < (UINTN) RelocEnd) {
> >
> >          Fixup = PeCoffLoaderImageAddress (&ImageContext, RelocBase-
> >VirtualAddress + (*Reloc & 0xFFF), 0);
> >          if (Fixup == NULL) {
> >
> 
> I think this patch is good enough, but it seems to miss the size==0 check that
> Dandan asked for.
> 
> Thanks,
> laszlo