https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103940
--- Comment #3 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by David Malcolm <dmalc...@gcc.gnu.org>: https://gcc.gnu.org/g:2c16dfe6268eeeb4b7924ff423e274fa00894a4d commit r12-6526-g2c16dfe6268eeeb4b7924ff423e274fa00894a4d Author: David Malcolm <dmalc...@redhat.com> Date: Tue Jan 11 15:57:39 2022 -0500 analyzer: complain about tainted sizes with "access" attribute [PR103940] GCC 10 gained the "access" function and type attribute, which optionally can take a size-index param: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html -fanalyzer in trunk (for GCC 12) has gained a -Wanalyzer-tainted-size to complain about attacker-controlled size values, but this was only being used deep inside the region-model code when handling the hardcoded known behavior of certain functions (memset, IIRC). This patch extends -Wanalyzer-tainted-size to also complain about unsanitized attacker-controlled values being passed to function parameters marked as a size via the "access" attribute. Note that -fanalyzer-checker=taint is currently required in addition to -fanalyzer to use this warning, due to scaling issues (see bug 103533). gcc/analyzer/ChangeLog: PR analyzer/103940 * engine.cc (impl_sm_context::impl_sm_context): Add "unknown_side_effects" param and use it to initialize new m_unknown_side_effects field. (impl_sm_context::unknown_side_effects_p): New. (impl_sm_context::m_unknown_side_effects): New. (exploded_node::on_stmt): Pass unknown_side_effects to sm_ctxt ctor. * sm-taint.cc: Include "stringpool.h" and "attribs.h". (tainted_size::tainted_size): Drop "dir" param. (tainted_size::get_kind): Drop "FINAL". (tainted_size::emit): Likewise. (tainted_size::m_dir): Drop unused field. (class tainted_access_attrib_size): New subclass. (taint_state_machine::on_stmt): Call check_for_tainted_size_arg on external functions with unknown side effects. (taint_state_machine::check_for_tainted_size_arg): New. (region_model::check_region_for_taint): Drop "dir" param from tainted_size ctor. * sm.h (sm_context::unknown_side_effects_p): New. gcc/testsuite/ChangeLog: PR analyzer/103940 * gcc.dg/analyzer/taint-size-access-attr-1.c: New test. Signed-off-by: David Malcolm <dmalc...@redhat.com>
