diff options
| -rw-r--r-- | ChangeLog | 10 | ||||
| -rw-r--r-- | lib/putenv.c | 32 | ||||
| -rw-r--r-- | m4/putenv.m4 | 6 | ||||
| -rw-r--r-- | modules/putenv | 2 |
4 files changed, 49 insertions, 1 deletions
@@ -1,3 +1,13 @@ +2013-02-14 Paul Eggert <eggert@cs.ucla.edu> + + putenv: fix heap corruption with mixed putenv/_putenv + Problem reported by Michael Goffioul in + <http://lists.gnu.org/archive/html/bug-gnulib/2013-02/msg00061.html>. + * lib/putenv.c (putenv) [HAVE__PUTENV]: + Rely on _putenv to allocate the new environment. + * m4/putenv.m4 (gl_PREREQ_PUTENV): New macro. + * modules/putenv (configure.ac): Use it. + 2013-02-11 Paul Eggert <eggert@cs.ucla.edu> unsetenv etc.: port to Solaris 11 + GNU Emacs diff --git a/lib/putenv.c b/lib/putenv.c index 5f0fedaf9c..0ec392f866 100644 --- a/lib/putenv.c +++ b/lib/putenv.c @@ -115,6 +115,37 @@ putenv (char *string) if (*ep == NULL) { +#if HAVE__PUTENV + /* Rely on _putenv to allocate the new environment. If other + parts of the application use _putenv, the !HAVE__PUTENV code + would fight over who owns the environ vector, causing a crash. */ + if (name_end[1]) + return _putenv (string); + else + { + /* _putenv ("NAME=") unsets NAME, so invoke _putenv ("NAME=x") + to allocate the environ vector and then replace the new + entry with "NAME=". */ + int putenv_result, putenv_errno; + char *name_x = malloc (name_end - string + sizeof "=x"); + if (!name_x) + return -1; + memcpy (name_x, string, name_end - string + 1); + name_x[name_end - string + 1] = 'x'; + name_x[name_end - string + 2] = 0; + putenv_result = _putenv (name_x); + putenv_errno = errno; + for (ep = environ; *ep; ep++) + if (*ep == name_x) + { + *ep = string; + break; + } + free (name_x); + __set_errno (putenv_errno); + return putenv_result; + } +#else static char **last_environ = NULL; char **new_environ = (char **) malloc ((size + 2) * sizeof (char *)); if (new_environ == NULL) @@ -126,6 +157,7 @@ putenv (char *string) free (last_environ); last_environ = new_environ; environ = new_environ; +#endif } else *ep = string; diff --git a/m4/putenv.m4 b/m4/putenv.m4 index 9de53527a7..03ed4f97db 100644 --- a/m4/putenv.m4 +++ b/m4/putenv.m4 @@ -48,3 +48,9 @@ AC_DEFUN([gl_FUNC_PUTENV], ;; esac ]) + +# Prerequisites of lib/putenv.c. +AC_DEFUN([gl_PREREQ_PUTENV], +[ + AC_CHECK_FUNCS([_putenv]) +]) diff --git a/modules/putenv b/modules/putenv index 3321a5e95f..e39f1450f6 100644 --- a/modules/putenv +++ b/modules/putenv @@ -14,6 +14,7 @@ configure.ac: gl_FUNC_PUTENV if test $REPLACE_PUTENV = 1; then AC_LIBOBJ([putenv]) + gl_PREREQ_PUTENV fi gl_STDLIB_MODULE_INDICATOR([putenv]) @@ -27,4 +28,3 @@ LGPL Maintainer: Jim Meyering, glibc - |