+++ This bug was initially created as a clone of Bug #1196114 +++ System startup hangs after fallback.efi appears to cause an invalid memory access. The UEFI assert mentioned in bz#1196114: "ASSERT .../MdeModulePkg/Core/Dxe/Mem/Pool.c(488): Tail->Signature == ((('p') | ('t' << 8)) | ((('a') | ('l' << 8)) << 16))" ...is reproducible on other EFI platforms. The hang can be reproduced by installing Fedora 24 onto a qemu Linux VM in EFI mode [1]. [1]: https://fedoraproject.org/wiki/Using_UEFI_with_QEMU
Tagging Peter for info as package administrator. I'll note that if I extract the fallback.efi binary out of the CentOS 7 build of the shim package and place it on the target image it resolves the problem. The version from CentOS is v0.9 while Fedora is back at v0.8, so it seems like all we need is to synchronize Fedora on v0.9.
Dan, I changed the Hardware field on clone-origin bug 1196114 to "All", and I also bumped the Version field to 24 there. Please see bug 1196114 comment 16 as well. With that, these two bugs are now identical, so I'm closing this one as a duplicate. Thanks. *** This bug has been marked as a duplicate of bug 1196114 ***