If the SULOG_FILE does not exist when an su session is logged, make sure

the file is created with group root, instead of using the group of the
caller.

diff --git a/ChangeLog b/ChangeLog
index 608d0bbc885b56dc9a700c674268416869444269..a701e8c233459b75ffcea990b6f64e8746ed7dfe 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2008-04-27  Nicolas François  <nicolas.francois@centraliens.net>
+
+       * NEWS, libmisc/sulog.c: If the SULOG_FILE does not exist when an
+       su session is logged, make sure the file is created with group
+       root, instead of using the group of the caller.
+
 2008-04-27  Nicolas François  <nicolas.francois@centraliens.net>
 
        * NEWS, libmisc/fields.c, src/chfn.c, man/chfn.1.xml: Allow

diff --git a/NEWS b/NEWS
index 6ce02c0563ecc204a7576a007838b58b830be1c3..f5d42106083414fdd9550f708259c190ee9b75e7 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -12,6 +12,10 @@ shadow-4.1.1 -> shadow-4.1.2                                         UNRELEASED
 - chfn
   * Allow non-US-ASCII characters in the GECOS fields ("name", "room
     number", and "other info" fields).
+- su
+  * If the SULOG_FILE does not exist when an su session is logged, make
+    sure the file is created with group root, instead of using the group
+    of the caller.
 
 shadow-4.1.0 -> shadow-4.1.1                                           02-04-2008
 

diff --git a/libmisc/sulog.c b/libmisc/sulog.c
index b6f9eed436382183fffb9d9655c4777fd191dea8..f3aee2d3ab93ec781cb4e8d6ad57741fb88d7113 100644 (file)
--- a/libmisc/sulog.c
+++ b/libmisc/sulog.c
@@ -48,6 +48,7 @@ void sulog (const char *tty, int success, const char *oldname, const char *name)
        struct tm *tm;
        FILE *fp;
        mode_t oldmask;
+       gid_t oldgid = 0;
 
        if (success) {
                SYSLOG ((LOG_INFO,
@@ -60,9 +61,26 @@ void sulog (const char *tty, int success, const char *oldname, const char *name)
        if ((sulog_file = getdef_str ("SULOG_FILE")) == (char *) 0)
                return;
 
+       oldgid = getgid ();
        oldmask = umask (077);
+       /* Switch to group root to avoid creating the sulog file with
+        * the wrong group ownership. */
+       if ((oldgid != 0) && (setgid (0) != 0)) {
+               SYSLOG ((LOG_INFO,
+                        "su session not logged to %s", sulog_file));
+               /* Continue, but do not switch back to oldgid later */
+               oldgid = 0;
+       }
        fp = fopen (sulog_file, "a+");
        umask (oldmask);
+       if ((oldgid != 0) && (setgid (oldgid) != 0)) {
+               perror ("setgid");
+               SYSLOG ((LOG_ERR,
+                        "can't switch back to group `%d' in sulog",
+                        oldgid));
+               /* Do not return if the group permission were raised. */
+               exit (1);
+       }
        if (fp == (FILE *) 0)
                return;         /* can't open or create logfile */