lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Tue, 28 May 2013 10:35:05 +0200 From: Ingo Molnar <mingo@...nel.org> To: Matt Fleming <matt@...sole-pimps.org> Cc: Russ Anderson <rja@....com>, Matthew Garrett <matthew.garrett@...ula.com>, matt.fleming@...el.com, linux-efi@...r.kernel.org, x86@...nel.org, linux-kernel@...r.kernel.org, Thomas Gleixner <tglx@...utronix.de>, "H. Peter Anvin" <hpa@...ux.intel.com>, Borislav Petkov <bp@...en8.de> Subject: Re: [regression, bisected] x86: efi: Pass boot services variable info to runtime code * Matt Fleming <matt@...sole-pimps.org> wrote: > What appears to be happening is that your the EFI runtime services code > is calling into the EFI boot services code, which is definitely a bug in > your firmware because we're at runtime, but we've seen other machines > that do similar things so we usually handle it just fine. However, what > makes your case different, and the reason you see the above splat, is > that it's using the physical address of the EFI boot services region, > not the virtual one we setup with SetVirtualAddressMap(). Which is a > second firmware bug. Again, we have seen other machines that access > physical addresses after SetVirtualAddressMap(), but until now we > haven't had any non-optional code that triggered them. > > The only reason I can see that the offending commit would introduce this > problem is because it calls QueryVariableInfo() at boot time. I notice > that your machine is an SGI UV one, is there any chance you could get a > firmware fix for this? If possible, it would be also good to confirm > that it's this chunk of code in setup_efi_vars(), > > status = efi_call_phys4(sys_table->runtime->query_variable_info, > EFI_VARIABLE_NON_VOLATILE | > EFI_VARIABLE_BOOTSERVICE_ACCESS | > EFI_VARIABLE_RUNTIME_ACCESS, &store_size, > &remaining_size, &var_size); > > that later makes GetNextVariable() jump to the physical address of the > EFI Boot Services region. Because if not, we need to do some more > digging. > > Borislav, how are your 1:1 mapping patches coming along? In theory, once > those are merged we can gracefully workaround these kinds of issues. Handling these gracefully without crashing boxes or expecting firmware to be sane (which is wishful thinking) would be _SO_ preferred ... I suspect 1:1 mapped is what Windows does - and we simply need to provide a Windows-EFI compatible environment (which is reality), not just an EFI-spec environment (which is a fiction). Thanks, Ingo -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists