On 14 May 2018 at 08:57, Ingo Molnar <mingo@xxxxxxxxxx> wrote: > > * Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx> wrote: > >> Mixed mode allows a kernel built for x86_64 to interact with 32-bit >> EFI firmware, but requires us to define all struct definitions carefully >> when it comes to pointer sizes. efi_pci_io_protocol32 currently uses a >> void* for the 'romimage' field, which will be interpreted as a 64-bit >> field on such kernels, potentially resulting in bogus memory references >> and subsequent crashes. > > Yeah, so the first confusion I ran into is: > > s/efi_pci_io_protocol32 > /efi_pci_io_protocol_32 > > Once I found it in the code I made this change: > > s/efi: fix efi_pci_io_protocol32 prototype for mixed mode > /efi: Fix 'struct efi_pci_io_protocol32' definition for mixed mode > > Because we normally use the 'prototype' name for function declarations, not for > data type definitions. Adding 'struct' and putting it between quotes makes it > obvious at a glance that we are talking about a structure definition here. > OK. > BTW., since it's marked -stable, due to: > > > potentially resulting in bogus memory references > > and subsequent crashes. > > I'm moving it to efi/urgent: the principle here is that if a patch is urgent > enough for -stable then it should generally not wait for the next merge window. > The issue was found by inspection rather than a crash report, so I was in doubt about this. > Also, because this actually fixes a crash, I extended the title to spell this out > more clearly: > > Subject: efi: Avoid potential crashes, fix the 'struct efi_pci_io_protocol_32' definition for mixed mode > > ... which also makes it easier for maintainers of older stable kernels to decide > whether to backport the patch or not. > OK. > Anyway, the patch is looking good otherwise, no need to resend. > > Thanks, > > Ingo -- To unsubscribe from this list: send the line "unsubscribe linux-efi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
