Mercurial > hg > octave-lojdl > gnulib-hg
changeset 17337:a72ac603a92f
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.
| author | Paul Eggert <eggert@cs.ucla.edu> |
|---|---|
| date | Thu, 14 Feb 2013 13:14:18 -0800 |
| parents | 603aa5fbb298 |
| children | 6f8d1926ece8 |
| files | ChangeLog lib/putenv.c m4/putenv.m4 modules/putenv |
| diffstat | 4 files changed, 49 insertions(+), 1 deletions(-) [+] |
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--- a/ChangeLog +++ b/ChangeLog @@ -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
--- a/lib/putenv.c +++ b/lib/putenv.c @@ -115,6 +115,37 @@ 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 @@ free (last_environ); last_environ = new_environ; environ = new_environ; +#endif } else *ep = string;