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Allow ssp_test:read to pass more reliably
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Authored by arichardson on Mar 1 2021, 2:55 PM.

Details

Summary

It appears that the stackframe layout can be slightly different depending on
compiler and target architecture. For example, when using CHERI LLVM for RISC-V
we can actually overflow the buffer by up to 8 bytes without SSP detecting it.
Fix this by increasing the overflow to 15 bytes.

Diff Detail

Repository
R10 FreeBSD src repository
Lint
Automatic diff as part of commit; lint not applicable.
Unit
Automatic diff as part of commit; unit tests not applicable.

Event Timeline

I think this is reasonable. I don't think we care whether SSP detects a stack overflow that overwrites only padding.

This revision is now accepted and ready to land.Mar 1 2021, 3:36 PM
contrib/netbsd-tests/lib/libc/ssp/t_ssp.sh
397

I wonder if this consistently works on NetBSD?

contrib/netbsd-tests/lib/libc/ssp/t_ssp.sh
397

Unlikely.