clapack: fix stack buffer overflow in ilaenv_ and prevent Intel runtime symbol interposition (!568) · Merge requests · YAC / YAC-dev

Summary

Two bugs in the bundled CLAPACK were fixed:

Buffer overflow in ilaenv_ (ilaenv.c): the f2c-translated local variable subnam was declared as char subnam[1] instead of the correct char subnam[6] (mistranslation of Fortran CHARACTER*6 SUBNAM). The subsequent uppercase-conversion loop and s_copy call wrote out of bounds.
Symbol interposition by Intel's Fortran runtime (libifcore/MKL): s_cmp, s_copy, and related f2c helpers share names with Intel's runtime, which exports them with 32-bit int length arguments (vs. f2c's 64-bit ftnlen). When Intel libraries appear in the same link the dynamic linker resolves these to Intel's ABI-incompatible versions, causing stack corruption. The existing blaswrap.h rename mechanism (already used for all BLAS symbols) is extended with 12 new #define renames covering the affected f2c helpers and LAPACK utility routines. The #include "blaswrap.h" is added to f2c.h so that the renames apply uniformly to all CLAPACK translation units, including F2CLIBS.

All code changes are covered by unit tests
Code coverage did not deteriorate
Code follows Style Guide
Documentation updated, if necessary
WIP: Manual running of configure/build jobs was successful
Update changelog, if changes are worth mentioning (Develop section in doc/src/changelog.dox, add section if not yet included)