https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110147
Bug ID: 110147 Summary: UBSAN error in rust-demangle.c: NULL pointer passed to memcpy Product: gcc Version: unknown Status: UNCONFIRMED Severity: normal Priority: P3 Component: demangler Assignee: unassigned at gcc dot gnu.org Reporter: lukas.dresel at cs dot ucsb.edu Target Milestone: --- This was discovered using our hybrid fuzzer originally on `binutils` `nm-new`. It appears to be caused by passing the string "_RYC0.vdj\\lc[kniso,bz" to `rust_demangle`. In the second invocation of `str_buf_append`, the `memcpy` src pointer is set to NULL. I have added the attached `nm-new` binary with debug symbols which exhibits the error, and the reproducing testcase. The above string was extracted from gdb.