Skip to content

Add info on minimal UBSan runtime #931

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 4 commits into from
Jul 10, 2025
Merged

Add info on minimal UBSan runtime #931

Changes from 1 commit
Commits
Show all changes
4 commits
Select commit Hold shift + click to select a range
eb70445
Add info on minimal UBSan runtime
yugr Jun 22, 2025
2e11f27
Update docs/Compiler-Hardening-Guides/Compiler-Options-Hardening-Guid…
yugr Jun 27, 2025
661ba58
Update docs/Compiler-Hardening-Guides/Compiler-Options-Hardening-Guid…
yugr Jun 27, 2025
1ea1177
Also mention -fsanitize-trap=undefined as a way to enable minimal run…
yugr Jun 29, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
4 changes: 3 additions & 1 deletion docs/Compiler-Hardening-Guides/Compiler-Options-Hardening-Guide-for-C-and-C++.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1206,7 +1206,7 @@ While more efficient compared to dynamic analysis, sanitizers are still prohibit

As with all testing practices, sanitizers cannot absolutely prove the absence of bugs. However, when used appropriately and regularly they can help in identifying latent memory, concurrency, and undefined behavior-related bugs which may be difficult to pinpoint.

Sanitizers should not be used for hardening in production environments, particularly for Set User ID (SUID) binaries, as they expose operational parameters via environmental variables which can be manipulated to clobber root-owned files and privilege escalation[^Nagy2016].
Sanitizers should not be used for hardening in production environments (apart from UBSan with minimal runtime - see below), particularly for Set User ID (SUID) binaries, as they expose operational parameters via environmental variables which can be manipulated to clobber root-owned files and privilege escalation[^Nagy2016].

[^Nagy2016]: Nagy , Szabolcs, [Address Sanitizer local root](https://www.openwall.com/lists/oss-security/2016/02/17/9), Openwall mailing list, 2016-02-16.

Expand Down Expand Up @@ -1317,6 +1317,8 @@ To enable UBSan add `-fsanitize=undefined` to the compiler flags (`CFLAGS` for C

The run-time behavior of UBSan can be influenced using the `UBSAN_OPTIONS` environment variable. If set to `UBSAN_OPTIONS=help=1` the available options are shown at startup of the instrumented program.

Unlike other sanitizers, UBSan comes with an option to enable a minimal runtime which does not expose additional attack surfaces and can be enabled in production environments. You can use `-fsanitize-minimal-runtime` flag to enable it.

[^gcc-instrumentation]: GCC team, [Program Instrumentation Options](https://gcc.gnu.org/onlinedocs/gcc/Instrumentation-Options.html#Instrumentation-Options), GCC Manual, 2023-07-27.

[^clang-ubsan]: LLVM team, [UndefinedBehaviorSanitizer](https://clang.llvm.org/docs/UndefinedBehaviorSanitizer.html), Clang documentation, 2023-03-17.
Expand Down