Messages in this thread | | | Date | Wed, 19 Jun 2019 16:58:12 -0400 | From | Sasha Levin <> | Subject | Re: [PATCH AUTOSEL 4.19 17/49] efi/x86/Add missing error handling to old_memmap 1:1 mapping code |
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On Sun, Jun 09, 2019 at 08:14:29PM +0200, Ard Biesheuvel wrote: >On Sat, 8 Jun 2019 at 13:43, Sasha Levin <sashal@kernel.org> wrote: >> >> From: Gen Zhang <blackgod016574@gmail.com> >> >> [ Upstream commit 4e78921ba4dd0aca1cc89168f45039add4183f8e ] >> >> The old_memmap flow in efi_call_phys_prolog() performs numerous memory >> allocations, and either does not check for failure at all, or it does >> but fails to propagate it back to the caller, which may end up calling >> into the firmware with an incomplete 1:1 mapping. >> >> So let's fix this by returning NULL from efi_call_phys_prolog() on >> memory allocation failures only, and by handling this condition in the >> caller. Also, clean up any half baked sets of page tables that we may >> have created before returning with a NULL return value. >> >> Note that any failure at this level will trigger a panic() two levels >> up, so none of this makes a huge difference, but it is a nice cleanup >> nonetheless. >> >> [ardb: update commit log, add efi_call_phys_epilog() call on error path] >> >> Signed-off-by: Gen Zhang <blackgod016574@gmail.com> >> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> >> Cc: Linus Torvalds <torvalds@linux-foundation.org> >> Cc: Peter Zijlstra <peterz@infradead.org> >> Cc: Rob Bradford <robert.bradford@intel.com> >> Cc: Thomas Gleixner <tglx@linutronix.de> >> Cc: linux-efi@vger.kernel.org >> Link: http://lkml.kernel.org/r/20190525112559.7917-2-ard.biesheuvel@linaro.org >> Signed-off-by: Ingo Molnar <mingo@kernel.org> >> Signed-off-by: Sasha Levin <sashal@kernel.org> > >This was already discussed in the thread that proposed this patch for >stable: please don't queue this right now, the patches are more likely >to harm than hurt, and they certainly don't fix a security >vulnerability, as has been claimed.
I've dropped this, thank you.
-- Thanks, Sasha
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