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libunwind is built without shadow stack support. Therefore, Fedora applications that link against libunwind are lacking protection at runtime. As far as I can tell, this is due to some assembly files that are not annotated and an upstream fix already exists for the same: https://github.com/libunwind/libunwind/commit/84607272d8a9bd8b19d2ac720641feab4bc2dc91 https://github.com/libunwind/libunwind/commit/155b3d90f4a0d5fe99f126da0ddbc6c76d0b3e71 Some background for why this bug is being filed and marked with a "High" severity: We (the glibc team) are planning to enable Shadow Stack protection by default in Fedora 45, and this bug report is a result of early testing. Here is a WIP/draft Fedora System-Wide Change Proposal: https://fedoraproject.org/wiki/Changes/ShadowStack There are some notes in the Documentation section of the change proposal on how to identify and fix issues such as these: https://fedoraproject.org/wiki/Changes/ShadowStack#Documentation However, in the case of libunwind, backporting the fixes mentioned might suffice. Reproducible: Always
I'm not sure what's going on with the upstream, I think maybe the 1.8.3 code is different from the "master" branch in key ways, but these changes don't seem to apply (even manually) to that tree. I think we might need to wait for upstream to push another stable release.
This bug appears to have been reported against 'rawhide' during the Fedora Linux 45 development cycle. Changing version to 45.