Backport 2.28: Fix false positives in constant time tests using MSan with Clang 16 #9943
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In the documentation of `MBEDTLS_TEST_CONSTANT_FLOW_MEMSAN`, note that since Clang 16, an extra command line option `-fsanitize-memory-param-retval` is required. As documented in the release notes https://releases.llvm.org/16.0.0/tools/clang/docs/ReleaseNotes.html#sanitizers since Clang 16, MSan forbids passing "uninitialized" values in and out of functions. In constant-flow testing, "uninitialized" values are actually secrets that must be manipulated with a data-independent flow, and it's perfectly fine to pass these in and out of functions. Fix Mbed-TLS#9921 Signed-off-by: Gilles Peskine <[email protected]>
New CMake build types CFMemSan, CFMemSanDbg to take care of differing compiler command lines with Clang <15 and Clang >=16. Signed-off-by: Gilles Peskine <[email protected]>
Support Clang >=16 in component_test_memsan_constant_flow. Modern versions of Clang require an extra compiler option to avoid false positives. Fixes Mbed-TLS#9921. Signed-off-by: Gilles Peskine <[email protected]>
Add some basic checks of constant flow sanitizers. In particular, detect the specific way in which Clang 16 broke our constant-flow testing (by default, "uninitialized" values may not be passed to or returned from functions). Signed-off-by: Gilles Peskine <[email protected]>
Signed-off-by: Gilles Peskine <[email protected]>
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This was referenced Jan 30, 2025
It wasn't getting declared in some configurations (e.g. config-no-entropy.h). Signed-off-by: Gilles Peskine <[email protected]>
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Closing as the last 2.28 release has gone out and it will no longer be maintained |
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Fix false positives of constant-flow testing when using
MBEDTLS_TEST_CONSTANT_FLOW_MEMSANon Clang 16 and above. Fixes #9921. Simple backport of #9922.PR checklist