Re: [PATCH 4/4] ef/libstub: arm/arm64: randomize the base of the UEFI rt services region

2017-04-10 Thread Ard Biesheuvel
On 10 April 2017 at 10:41, Mark Rutland wrote: > On Fri, Apr 07, 2017 at 04:51:16PM +0100, Ard Biesheuvel wrote: >> On 7 April 2017 at 16:47, James Morse wrote: >> > On 24/03/17 13:24, Ard Biesheuvel wrote: >> >> Update the allocation logic for the

Re: [PATCH 4/4] ef/libstub: arm/arm64: randomize the base of the UEFI rt services region

2017-04-10 Thread Mark Rutland
On Fri, Apr 07, 2017 at 04:51:16PM +0100, Ard Biesheuvel wrote: > On 7 April 2017 at 16:47, James Morse wrote: > > On 24/03/17 13:24, Ard Biesheuvel wrote: > >> Update the allocation logic for the virtual mapping of the UEFI runtime > >> services to start from a randomized

Re: [PATCH 4/4] ef/libstub: arm/arm64: randomize the base of the UEFI rt services region

2017-04-07 Thread James Morse
Hi Ard, On 07/04/17 16:51, Ard Biesheuvel wrote: > That is quite interesting, to be honest, because that patch should > effectively be a NOP on systems that do not implement > EFI_RNG_PROTOCOL. > > Could you run this from the UEFI shell please? > >

Re: [PATCH 4/4] ef/libstub: arm/arm64: randomize the base of the UEFI rt services region

2017-04-07 Thread Ard Biesheuvel
On 7 April 2017 at 16:47, James Morse wrote: > Hi Ard, > > On 24/03/17 13:24, Ard Biesheuvel wrote: >> Update the allocation logic for the virtual mapping of the UEFI runtime >> services to start from a randomized base address if KASLR is in effect, >> and if the UEFI

Re: [PATCH 4/4] ef/libstub: arm/arm64: randomize the base of the UEFI rt services region

2017-04-07 Thread James Morse
Hi Ard, On 24/03/17 13:24, Ard Biesheuvel wrote: > Update the allocation logic for the virtual mapping of the UEFI runtime > services to start from a randomized base address if KASLR is in effect, > and if the UEFI firmware exposes an implementation of EFI_RNG_PROTOCOL. > > This makes it more

[PATCH 4/4] ef/libstub: arm/arm64: randomize the base of the UEFI rt services region

2017-03-24 Thread Ard Biesheuvel
Update the allocation logic for the virtual mapping of the UEFI runtime services to start from a randomized base address if KASLR is in effect, and if the UEFI firmware exposes an implementation of EFI_RNG_PROTOCOL. This makes it more difficult to predict the location of exploitable data