https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95104
--- Comment #16 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The releases/gcc-9 branch has been updated by Harald Anlauf <anl...@gcc.gnu.org>: https://gcc.gnu.org/g:0d607ecbf125551513e182a181ca9c6e25dc7609 commit r9-8633-g0d607ecbf125551513e182a181ca9c6e25dc7609 Author: Harald Anlauf <anl...@gmx.de> Date: Thu May 28 21:53:17 2020 +0200 PR fortran/95104 - Segfault on a legal WAIT statement The initial commit for this PR uncovered a latent issue with unit locking in the Fortran run-time library. Add check for valid unit. 2020-05-28 Harald Anlauf <anl...@gmx.de> libgfortran/ PR libfortran/95104 * io/unit.c (unlock_unit): Guard by check for NULL pointer. (cherry picked from commit 6ce3d791dfcba469e709935aba5743640f7d4959)