commit 969e9733c7d17edf1e239a73fa172f357561f440

Author: Florian Weimer <fweimer@redhat.com>

Date:   Tue Feb 21 09:20:28 2023 +0100

    gshadow: Matching sgetsgent, sgetsgent_r ERANGE handling (bug 30151)

    Before this change, sgetsgent_r did not set errno to ERANGE, but

    sgetsgent only check errno, not the return value from sgetsgent_r.

    Consequently, sgetsgent did not detect any error, and reported

    success to the caller, without initializing the struct sgrp object

    whose address was returned.

    This commit changes sgetsgent_r to set errno as well.  This avoids

    similar issues in applications which only change errno.

    Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>

diff --git a/gshadow/Makefile b/gshadow/Makefile

index 796fbbf473..a95524593a 100644

--- a/gshadow/Makefile

+++ b/gshadow/Makefile

@@ -26,7 +26,7 @@ headers		= gshadow.h

 routines	= getsgent getsgnam sgetsgent fgetsgent putsgent \

 		  getsgent_r getsgnam_r sgetsgent_r fgetsgent_r

-tests = tst-gshadow tst-putsgent tst-fgetsgent_r

+tests = tst-gshadow tst-putsgent tst-fgetsgent_r tst-sgetsgent

 CFLAGS-getsgent_r.c += -fexceptions

 CFLAGS-getsgent.c += -fexceptions

diff --git a/gshadow/sgetsgent_r.c b/gshadow/sgetsgent_r.c

index ea085e91d7..c75624e1f7 100644

--- a/gshadow/sgetsgent_r.c

+++ b/gshadow/sgetsgent_r.c

@@ -61,7 +61,10 @@ __sgetsgent_r (const char *string, struct sgrp *resbuf, char *buffer,

       buffer[buflen - 1] = '\0';

       sp = strncpy (buffer, string, buflen);

       if (buffer[buflen - 1] != '\0')

-	return ERANGE;

+	{

+	  __set_errno (ERANGE);

+	  return ERANGE;

+	}

     }

   else

     sp = (char *) string;

diff --git a/gshadow/tst-sgetsgent.c b/gshadow/tst-sgetsgent.c

new file mode 100644

index 0000000000..0370c10fd0

--- /dev/null

+++ b/gshadow/tst-sgetsgent.c

@@ -0,0 +1,69 @@

+/* Test large input for sgetsgent (bug 30151).

+   Copyright (C) 2023 Free Software Foundation, Inc.

+   This file is part of the GNU C Library.

+

+   The GNU C Library is free software; you can redistribute it and/or

+   modify it under the terms of the GNU Lesser General Public

+   License as published by the Free Software Foundation; either

+   version 2.1 of the License, or (at your option) any later version.

+

+   The GNU C Library is distributed in the hope that it will be useful,

+   but WITHOUT ANY WARRANTY; without even the implied warranty of

+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

+   Lesser General Public License for more details.

+

+   You should have received a copy of the GNU Lesser General Public

+   License along with the GNU C Library; if not, see

+   <https://www.gnu.org/licenses/>.  */

+

+#include <gshadow.h>

+#include <stddef.h>

+#include <support/check.h>

+#include <support/support.h>

+#include <support/xmemstream.h>

+#include <stdlib.h>

+

+static int

+do_test (void)

+{

+  /* Create a shadow group with 1000 members.  */

+  struct xmemstream mem;

+  xopen_memstream (&mem;;

+  const char *passwd = "k+zD0nucwfxAo3sw1NXUj6K5vt5M16+X0TVGdE1uFvq5R8V7efJ";

+  fprintf (mem.out, "group-name:%s::m0", passwd);

+  for (int i = 1; i < 1000; ++i)

+    fprintf (mem.out, ",m%d", i);

+  xfclose_memstream (&mem;;

+

+  /* Call sgetsgent.  */

+  char *input = mem.buffer;

+  struct sgrp *e = sgetsgent (input);

+  TEST_VERIFY_EXIT (e != NULL);

+  TEST_COMPARE_STRING (e->sg_namp, "group-name");

+  TEST_COMPARE_STRING (e->sg_passwd, passwd);

+  /* No administrators.  */

+  TEST_COMPARE_STRING (e->sg_adm[0], NULL);

+  /* Check the members list.  */

+  for (int i = 0; i < 1000; ++i)

+    {

+      char *member = xasprintf ("m%d", i);

+      TEST_COMPARE_STRING (e->sg_mem[i], member);

+      free (member);

+    }

+  TEST_COMPARE_STRING (e->sg_mem[1000], NULL);

+

+  /* Check that putsgent brings back the input string.  */

+  xopen_memstream (&mem;;

+  TEST_COMPARE (putsgent (e, mem.out), 0);

+  xfclose_memstream (&mem;;

+  /* Compare without the trailing '\n' that putsgent added.  */

+  TEST_COMPARE (mem.buffer[mem.length - 1], '\n');

+  mem.buffer[mem.length - 1] = '\0';

+  TEST_COMPARE_STRING (mem.buffer, input);

+

+  free (mem.buffer);

+  free (input);

+  return 0;

+}

+

+#include <support/test-driver.c>