autofs-5.1.8 - fix sysconf(3) return handling

From: Fabian Groffen <grobian@gentoo.org>

The sysconf(3) return handling doesn't handle a -1 return with errno

not changed which indicated a maximum or minimum limit that's not

known.

Add handling of this case.

Signed-off-by: Fabian Groffen <grobian@gentoo.org>

Signed-off-by: Ian Kent <raven@themaw.net>

---

 CHANGELOG    |    1 +

 lib/mounts.c |   13 +++++++++++--

 2 files changed, 12 insertions(+), 2 deletions(-)

--- autofs-5.1.4.orig/CHANGELOG

+++ autofs-5.1.4/CHANGELOG

@@ -91,6 +91,7 @@

 - fix use after free in tree_mapent_delete_offset_tree().

 - fix memory leak in xdr_exports().

 - avoid calling pthread_getspecific() with NULL key_thread_attempt_id.

+- fix sysconf(3) return handling.

 xx/xx/2018 autofs-5.1.5

 - fix flag file permission.

--- autofs-5.1.4.orig/lib/mounts.c

+++ autofs-5.1.4/lib/mounts.c

@@ -2385,11 +2385,17 @@ void set_tsd_user_vars(unsigned int logo

 	/* Try to get passwd info */

+	/* sysconf may return -1 with unchanged errno to indicate unlimited

+	 * size, same for the call for _SC_GETGR_R_SIZE_MAX  below

+	 */

+	errno = 0;

 	tmplen = sysconf(_SC_GETPW_R_SIZE_MAX);

-	if (tmplen < 0) {

+	if (tmplen < 0 && errno != 0) {

 		error(logopt, "failed to get buffer size for getpwuid_r");

 		goto free_tsv;

 	}

+	if (tmplen < 0)

+		tmplen = 1024;	/* assume something reasonable */

 	pw_tmp = malloc(tmplen + 1);

 	if (!pw_tmp) {

@@ -2422,11 +2428,14 @@ void set_tsd_user_vars(unsigned int logo

 	/* Try to get group info */

+	errno = 0;

 	grplen = sysconf(_SC_GETGR_R_SIZE_MAX);

-	if (grplen < 0) {

+	if (grplen < 0 && errno != 0) {

 		error(logopt, "failed to get buffer size for getgrgid_r");

 		goto free_tsv_home;

 	}

+	if (grplen < 0)

+		grplen = 1024;

 	gr_tmp = NULL;

 	status = ERANGE;