[PATCH 0/4] aarch64: avoid mprotect(PROT_BTI|PROT_EXEC) [BZ #26831]

From: Szabolcs Nagy <szabolcs.nagy@arm.com>
To: libc-alpha@sourceware.org
Cc: Jeremy Linton <jeremy.linton@arm.com>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Mark Rutland <mark.rutland@arm.com>,
	Will Deacon <will.deacon@arm.com>,
	Mark Brown <broonie@kernel.org>,
	Florian Weimer <fweimer@redhat.com>,
	Kees Cook <keescook@chromium.org>,
	Salvatore Mesoraca <s.mesoraca16@gmail.com>,
	Lennart Poettering <mzxreary@0pointer.de>,
	Topi Miettinen <toiwoton@gmail.com>,
	linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	kernel-hardening@lists.openwall.com,
	linux-hardening@vger.kernel.org
Subject: [PATCH 0/4] aarch64: avoid mprotect(PROT_BTI|PROT_EXEC) [BZ #26831]
Date: Tue,  3 Nov 2020 10:25:37 +0000	[thread overview]
Message-ID: <cover.1604393169.git.szabolcs.nagy@arm.com> (raw)

Re-mmap executable segments instead of mprotecting them in
case mprotect is seccomp filtered.

For the kernel mapped main executable we don't have the fd
for re-mmap so linux needs to be updated to add BTI. (In the
presence of seccomp filters for mprotect(PROT_EXEC) the libc
cannot change BTI protection at runtime based on user space
policy so it is better if the kernel maps BTI compatible
binaries with PROT_BTI by default.)

Szabolcs Nagy (4):
  elf: Pass the fd to note processing [BZ #26831]
  elf: Move note processing after l_phdr is updated [BZ #26831]
  aarch64: Use mmap to add PROT_BTI instead of mprotect [BZ #26831]
  aarch64: Remove the bti link_map field [BZ #26831]

 elf/dl-load.c              | 38 ++++++++++++++++---------------
 elf/rtld.c                 |  4 ++--
 sysdeps/aarch64/dl-bti.c   | 46 ++++++++++++++++++++------------------
 sysdeps/aarch64/dl-prop.h  | 17 +++++++-------
 sysdeps/aarch64/linkmap.h  |  1 -
 sysdeps/generic/dl-prop.h  |  6 ++---
 sysdeps/generic/ldsodefs.h |  5 +++--
 sysdeps/x86/dl-prop.h      |  6 ++---
 8 files changed, 64 insertions(+), 59 deletions(-)

-- 
2.17.1