Messages in this thread | | | From | Willy Tarreau <> | Subject | [PATCH 0/8] tools/nolibc: add support for stack protector | Date | Sat, 25 Mar 2023 16:45:08 +0100 |
| |
Hello Paul,
This is essentially Thomas' work so instead of paraphrasing his work, I'm pasting his description below. I've tested his changes on all supported archs, applied a tiny modification with his permission to continue to support passing CFLAGS, and for me this is all fine. In a short summary this adds support for stack protector to i386 and x86_64 in nolibc, and the accompanying test to the selftest program.
A new test category was added, "protection", which currently has a single test. Archs that support it will report "OK" there and those that do not will report "SKIPPED", as is already the case for tests that cannot be run.
This was applied on top of your dev.2023.03.20a branch. I'm reasonably confident with the nature of the changes, so if your queue for 6.4 is not closed yet, it can be a good target, otherwise 6.5 will be fine as well.
Thanks in advance! Willy
Thomas' description below:
This is useful when using nolibc for security-critical tools. Using nolibc has the advantage that the code is easily auditable and sandboxable with seccomp as no unexpected syscalls are used. Using compiler-assistent stack protection provides another security mechanism.
For this to work the compiler and libc have to collaborate.
This patch adds the following parts to nolibc that are required by the compiler:
* __stack_chk_guard: random sentinel value * __stack_chk_fail: handler for detected stack smashes
In addition an initialization function is added that randomizes the sentinel value.
Only support for global guards is implemented. Register guards are useful in multi-threaded context which nolibc does not provide support for.
Link: https://lwn.net/Articles/584225/
Thomas Weißschuh (8): tools/nolibc: add definitions for standard fds tools/nolibc: add helpers for wait() signal exits tools/nolibc: tests: constify test_names tools/nolibc: add support for stack protector tools/nolibc: tests: fold in no-stack-protector cflags tools/nolibc: tests: add test for -fstack-protector tools/nolibc: i386: add stackprotector support tools/nolibc: x86_64: add stackprotector support
tools/include/nolibc/Makefile | 4 +- tools/include/nolibc/arch-i386.h | 7 ++- tools/include/nolibc/arch-x86_64.h | 5 ++ tools/include/nolibc/nolibc.h | 1 + tools/include/nolibc/stackprotector.h | 53 ++++++++++++++++ tools/include/nolibc/types.h | 2 + tools/include/nolibc/unistd.h | 5 ++ tools/testing/selftests/nolibc/Makefile | 11 +++- tools/testing/selftests/nolibc/nolibc-test.c | 64 +++++++++++++++++++- 9 files changed, 144 insertions(+), 8 deletions(-) create mode 100644 tools/include/nolibc/stackprotector.h
-- 2.17.5
| |