commit 4568f4bc0f116f097a13b1d931de93cf525ae204
author Christopher Ferris <cferris@google.com> Tue Oct 23 17:42:41 2018 -0700
committer Christopher Ferris <cferris@google.com> Mon Oct 29 18:08:09 2018 -0700
tree 2832d853a8b2dfa6f66f1c5d04d22df742b22d4d
parent 2a8460721ca219ea2d9bc00e0412297afd12df47

Verify that the elf matches the expected arch.

To avoid a case where a malicious app might try and trick the system to
create an elf and register object that mismatches, always verify that they
are the same arch.

Test: Ran unit tests.
Change-Id: I66978e9e02f8e4f396856912e7019528ead4838e

libbacktrace/UnwindStack.cpp

diff --git a/libbacktrace/UnwindStack.cpp b/libbacktrace/UnwindStack.cpp
index 4e7f761..fe28eba 100644
--- a/libbacktrace/UnwindStack.cpp
+++ b/libbacktrace/UnwindStack.cpp
@@ -49,6 +49,7 @@
   unwindstack::Unwinder unwinder(MAX_BACKTRACE_FRAMES + num_ignore_frames, stack_map->stack_maps(),
                                  regs, stack_map->process_memory());
   unwinder.SetResolveNames(stack_map->ResolveNames());
+  stack_map->SetArch(regs->Arch());
   if (stack_map->GetJitDebug() != nullptr) {
     unwinder.SetJitDebug(stack_map->GetJitDebug(), regs->Arch());
   }