Add a new "devsearch" Path setting to sudo.conf for configuring the

/dev paths to traverse instead of hard-coding a list in ttyname.c
The default value can be set at configure time.

INSTALL

@@ -368,6 +368,12 @@ Operating system-specific options:
 	Enable the creation of an Ubuntu-style admin flag file
 	the first time sudo is run.
 
+  --enable-devsearch=PATH
+        Set a system-specific search path of directories to look in
+        for device nodes.  Sudo uses this when mapping the process's
+	tty device number to a device name.  The default value is:
+            /dev/pts:/dev/vt:/dev/term:/dev/zcons:/dev/pty:/dev
+
   --with-bsm-audit
         Enable support for sudo BSM audit logs on systems that support it.
 	This includes recent versions of FreeBSD, Mac OS X and Solaris.

configure

@@ -722,6 +722,7 @@ timeout
 vardir
 rundir
 iolog_dir
+devsearch
 FILEDIGEST
 exampledir
 TMPFILES_D
@@ -959,6 +960,7 @@ enable_rpath
 enable_static_sudoers
 enable_shared_libutil
 enable_tmpfiles_d
+enable_devsearch
 with_selinux
 enable_gss_krb5_ccache_name
 enable_shared
@@ -1641,6 +1643,8 @@ Optional Features:
   --disable-shared-libutil
                           Disable use of the libsudo_util shared library.
   --enable-tmpfiles.d=DIR Set the path to the systemd tmpfiles.d directory.
+  --enable-devsearch=PATH The colon-delimited path to search for device nodes
+                          when determing the tty name.
   --enable-gss-krb5-ccache-name
                           Use GSS-API to set the Kerberos V cred cache name
   --enable-shared[=PKGS]  build shared libraries [default=yes]
@@ -3051,6 +3055,7 @@ $as_echo "$as_me: Configuring Sudo version $PACKAGE_VERSION" >&6;}
 
 
 
+
 
 
 #
@@ -3098,6 +3103,7 @@ pam_session=on
 pam_login_service=sudo
 PLUGINDIR=/usr/local/libexec/sudo
 FILEDIGEST=filedigest.lo
+devsearch="/dev/pts:/dev/vt:/dev/term:/dev/zcons:/dev/pty:/dev"
 #
 # End initial values for man page substitution
 #
@@ -6664,6 +6670,23 @@ else
 fi
 
 
+# Check whether --enable-devsearch was given.
+if test "${enable_devsearch+set}" = set; then :
+  enableval=$enable_devsearch; case $enableval in
+    yes)	# use default value
+		;;
+    no)		{ $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: Ignoring attempt to disable the device search path" >&5
+$as_echo "$as_me: WARNING: Ignoring attempt to disable the device search path" >&2;}
+		;;
+    *)		devsearch="$enableval"
+esac
+fi
+
+cat >>confdefs.h <<EOF
+#define _PATH_SUDO_DEVSEARCH "$devsearch"
+EOF
+
+
 
 # Check whether --with-selinux was given.
 if test "${with_selinux+set}" = set; then :

configure.ac

@@ -97,6 +97,7 @@ AC_SUBST([COMPAT_EXP])
 AC_SUBST([TMPFILES_D])
 AC_SUBST([exampledir])
 AC_SUBST([FILEDIGEST])
+AC_SUBST([devsearch])
 dnl
 dnl Variables that get substituted in docs (not overridden by environment)
 dnl
@@ -185,6 +186,7 @@ pam_session=on
 pam_login_service=sudo
 PLUGINDIR=/usr/local/libexec/sudo
 FILEDIGEST=filedigest.lo
+devsearch="/dev/pts:/dev/vt:/dev/term:/dev/zcons:/dev/pty:/dev"
 #
 # End initial values for man page substitution
 #
@@ -1531,6 +1533,17 @@ esac], [
     test -f /usr/lib/tmpfiles.d/systemd.conf && TMPFILES_D=/usr/lib/tmpfiles.d
 ])
 
+AC_ARG_ENABLE(devsearch,
+[AS_HELP_STRING([--enable-devsearch=PATH], [The colon-delimited path to search for device nodes when determing the tty name.])],
+[case $enableval in
+    yes)	# use default value
+		;;
+    no)		AC_MSG_WARN([Ignoring attempt to disable the device search path])
+		;;
+    *)		devsearch="$enableval"
+esac])
+SUDO_DEFINE_UNQUOTED(_PATH_SUDO_DEVSEARCH, "$devsearch")
+
 AC_ARG_WITH(selinux, [AS_HELP_STRING([--with-selinux], [enable SELinux support])],
 [case $with_selinux in
     yes)	SELINUX_USAGE="[[-r role]] [[-t type]] "

doc/sudo.conf.cat

@@ -106,6 +106,15 @@ DDEESSCCRRIIPPTTIIOONN
                _a_s_k_p_a_s_s may be overridden by the SUDO_ASKPASS environment
                variable.
 
+     devsearch
+               An ordered, colon-separated search path of directories to look
+               in for device nodes.  This is used when mapping the process's
+               tty device number to a device name.  Sudo will _n_o_t recurse into
+               subdirectories.  If terminal devices may be located in a
+               subdirectory of _/_d_e_v, that path must be explicitly listed in
+               _d_e_v_s_e_a_r_c_h.  The default value is:
+               /dev/pts:/dev/vt:/dev/term:/dev/zcons:/dev/pty:/dev
+
      noexec    The fully-qualified path to a shared library containing
                wrappers for the eexxeeccll(), eexxeeccllee(), eexxeeccllpp(), eexxeecctt(), eexxeeccvv(),
                eexxeeccvvee(), eexxeeccvvPP(), eexxeeccvvpp(), eexxeeccvvppee(), ffeexxeeccvvee(), ppooppeenn(),
@@ -418,4 +427,4 @@ DDIISSCCLLAAIIMMEERR
      file distributed with ssuuddoo or https://www.sudo.ws/license.html for
      complete details.
 
-Sudo 1.8.20                    October 15, 2016                    Sudo 1.8.20
+Sudo 1.8.21                      May 30, 2017                      Sudo 1.8.21

doc/sudo.conf.man.in

@@ -1,7 +1,7 @@
 .\" DO NOT EDIT THIS FILE, IT IS NOT THE MASTER!
 .\" IT IS GENERATED AUTOMATICALLY FROM sudo.conf.mdoc.in
 .\"
-.\" Copyright (c) 2010-2016 Todd C. Miller <Todd.Miller@courtesan.com>
+.\" Copyright (c) 2010-2017 Todd C. Miller <Todd.Miller@courtesan.com>
 .\"
 .\" Permission to use, copy, modify, and distribute this software for any
 .\" purpose with or without fee is hereby granted, provided that the above
@@ -16,7 +16,7 @@
 .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\" ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 .\"
-.TH "SUDO.CONF" "5" "October 15, 2016" "Sudo @PACKAGE_VERSION@" "File Formats Manual"
+.TH "SUDO.CONF" "5" "May 30, 2017" "Sudo @PACKAGE_VERSION@" "File Formats Manual"
 .nh
 .if n .ad l
 .SH "NAME"
@@ -238,6 +238,21 @@ may be overridden by the
 \fRSUDO_ASKPASS\fR
 environment variable.
 .TP 10n
+devsearch
+.br
+An ordered, colon-separated search path of directories to look in for
+device nodes.
+This is used when mapping the process's tty device number to a device name.
+Sudo will
+\fInot\fR
+recurse into subdirectories.
+If terminal devices may be located in a subdirectory of
+\fI/dev\fR,
+that path must be explicitly listed in
+\fIdevsearch\fR.
+The default value is:
+\fR/dev/pts:/dev/vt:/dev/term:/dev/zcons:/dev/pty:/dev\fR
+.TP 10n
 noexec
 The fully-qualified path to a shared library containing wrappers
 for the

doc/sudo.conf.mdoc.in

@@ -1,5 +1,5 @@
 .\"
-.\" Copyright (c) 2010-2016 Todd C. Miller <Todd.Miller@courtesan.com>
+.\" Copyright (c) 2010-2017 Todd C. Miller <Todd.Miller@courtesan.com>
 .\"
 .\" Permission to use, copy, modify, and distribute this software for any
 .\" purpose with or without fee is hereby granted, provided that the above
@@ -14,7 +14,7 @@
 .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\" ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 .\"
-.Dd October 15, 2016
+.Dd May 30, 2017
 .Dt SUDO.CONF @mansectform@
 .Os Sudo @PACKAGE_VERSION@
 .Sh NAME
@@ -215,6 +215,19 @@ The value of
 may be overridden by the
 .Ev SUDO_ASKPASS
 environment variable.
+.It devsearch
+An ordered, colon-separated search path of directories to look in for
+device nodes.
+This is used when mapping the process's tty device number to a device name.
+Sudo will
+.Em not
+recurse into subdirectories.
+If terminal devices may be located in a subdirectory of
+.Pa /dev ,
+that path must be explicitly listed in
+.Em devsearch .
+The default value is:
+.Li /dev/pts:/dev/vt:/dev/term:/dev/zcons:/dev/pty:/dev
 .It noexec
 The fully-qualified path to a shared library containing wrappers
 for the

include/sudo_conf.h

@@ -59,6 +59,7 @@ __dso_public const char *sudo_conf_askpass_path_v1(void);
 __dso_public const char *sudo_conf_sesh_path_v1(void);
 __dso_public const char *sudo_conf_noexec_path_v1(void);
 __dso_public const char *sudo_conf_plugin_dir_path_v1(void);
+__dso_public const char *sudo_conf_devsearch_path_v1(void);
 __dso_public struct sudo_conf_debug_list *sudo_conf_debugging_v1(void);
 __dso_public struct sudo_conf_debug_file_list *sudo_conf_debug_files_v1(const char *progname);
 __dso_public struct plugin_info_list *sudo_conf_plugins_v1(void);
@@ -71,6 +72,7 @@ __dso_public void sudo_conf_clear_paths_v1(void);
 #define sudo_conf_sesh_path() sudo_conf_sesh_path_v1()
 #define sudo_conf_noexec_path() sudo_conf_noexec_path_v1()
 #define sudo_conf_plugin_dir_path() sudo_conf_plugin_dir_path_v1()
+#define sudo_conf_devsearch_path() sudo_conf_devsearch_path_v1()
 #define sudo_conf_debugging() sudo_conf_debugging_v1()
 #define sudo_conf_debug_files(_a) sudo_conf_debug_files_v1((_a))
 #define sudo_conf_plugins() sudo_conf_plugins_v1()

lib/util/sudo_conf.c

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2009-2016 Todd C. Miller <Todd.Miller@courtesan.com>
+ * Copyright (c) 2009-2017 Todd C. Miller <Todd.Miller@courtesan.com>
  *
  * Permission to use, copy, modify, and distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
@@ -99,6 +99,7 @@ static struct sudo_conf_table sudo_conf_var_table[] = {
 #define SUDO_CONF_PATH_SESH		1
 #define SUDO_CONF_PATH_NOEXEC		2
 #define SUDO_CONF_PATH_PLUGIN_DIR	3
+#define SUDO_CONF_PATH_DEVSEARCH	4
 
 static struct sudo_conf_data {
     bool disable_coredump;
@@ -107,7 +108,7 @@ static struct sudo_conf_data {
     int max_groups;
     struct sudo_conf_debug_list debugging;
     struct plugin_info_list plugins;
-    struct sudo_conf_path_table path_table[5];
+    struct sudo_conf_path_table path_table[6];
 } sudo_conf_data = {
     true,
     true,
@@ -120,6 +121,7 @@ static struct sudo_conf_data {
 	{ "sesh", sizeof("sesh") - 1, false, _PATH_SUDO_SESH },
 	{ "noexec", sizeof("noexec") - 1, false, _PATH_SUDO_NOEXEC },
 	{ "plugin_dir", sizeof("plugin_dir") - 1, false, _PATH_SUDO_PLUGIN_DIR },
+	{ "devsearch", sizeof("devsearch") - 1, false, _PATH_SUDO_DEVSEARCH },
 	{ NULL }
     }
 };
@@ -451,6 +453,12 @@ sudo_conf_plugin_dir_path_v1(void)
     return sudo_conf_data.path_table[SUDO_CONF_PATH_PLUGIN_DIR].pval;
 }
 
+const char *
+sudo_conf_devsearch_path_v1(void)
+{
+    return sudo_conf_data.path_table[SUDO_CONF_PATH_DEVSEARCH].pval;
+}
+
 int
 sudo_conf_group_source_v1(void)
 {

lib/util/util.exp.in

@@ -7,6 +7,7 @@ sudo_conf_disable_coredump_v1
 sudo_conf_group_source_v1
 sudo_conf_max_groups_v1
 sudo_conf_noexec_path_v1
+sudo_conf_devsearch_path_v1
 sudo_conf_plugin_dir_path_v1
 sudo_conf_plugins_v1
 sudo_conf_probe_interfaces_v1

pathnames.h.in

@@ -123,6 +123,10 @@
 # undef _PATH_SUDO_PLUGIN_DIR
 #endif /* _PATH_SUDO_PLUGIN_DIR */
 
+#ifndef _PATH_SUDO_DEVSEARCH
+# undef _PATH_SUDO_DEVSEARCH
+#endif /* _PATH_SUDO_DEVSEARCH */
+
 #ifndef _PATH_VI
 # undef _PATH_VI
 #endif /* _PATH_VI */

src/ttyname.c

@@ -62,12 +62,6 @@
 
 #include "sudo.h"
 
-#if defined(HAVE_STRUCT_DIRENT_D_NAMLEN) && HAVE_STRUCT_DIRENT_D_NAMLEN
-# define NAMLEN(dirent)	(dirent)->d_namlen
-#else
-# define NAMLEN(dirent)	strlen((dirent)->d_name)
-#endif
-
 /*
  * How to access the tty device number in struct kinfo_proc.
  */
@@ -145,22 +139,9 @@ sudo_ttyname_dev(dev_t tdev, char *name, size_t namelen)
 }
 #elif defined(HAVE_STRUCT_PSINFO_PR_TTYDEV) || defined(HAVE_PSTAT_GETPROC) || defined(__linux__)
 /*
- * Device nodes and directories to search before searching all of /dev
+ * Device nodes to ignore.
  */
-static char *search_devs[] = {
-    "/dev/console",
-    "/dev/pts/",	/* POSIX pty */
-    "/dev/vt/",		/* Solaris virtual console */
-    "/dev/term/",	/* Solaris serial ports */
-    "/dev/zcons/",	/* Solaris zone console */
-    "/dev/pty/",	/* HP-UX old-style pty */
-    NULL
-};
-
-/*
- * Device nodes to ignore when searching all of /dev
- */
-static char *ignore_devs[] = {
+static const char *ignore_devs[] = {
     "/dev/stdin",
     "/dev/stdout",
     "/dev/stderr",
@@ -207,7 +188,7 @@ sudo_ttyname_scan(const char *dir, dev_t rdev, char *name, size_t namelen)
 	"scanning for dev %u in %s", (unsigned int)rdev, dir);
 
     sdlen = strlen(dir);
-    if (dir[sdlen - 1] == '/')
+    while (sdlen > 0 && dir[sdlen - 1] == '/')
 	sdlen--;
     if (sdlen + 1 >= sizeof(pathbuf)) {
 	errno = ERANGE;
@@ -215,32 +196,33 @@ sudo_ttyname_scan(const char *dir, dev_t rdev, char *name, size_t namelen)
     }
     memcpy(pathbuf, dir, sdlen);
     pathbuf[sdlen++] = '/';
-    pathbuf[sdlen] = '\0';
 
     while ((dp = readdir(d)) != NULL) {
 	struct stat sb;
-	size_t d_len, len;
 
 	/* Skip anything starting with "." */
 	if (dp->d_name[0] == '.')
 	    continue;
 
-	d_len = NAMLEN(dp);
-	if (sdlen + d_len >= sizeof(pathbuf))
+	pathbuf[sdlen] = '\0';
+	if (strlcat(pathbuf, dp->d_name, sizeof(pathbuf)) >= sizeof(pathbuf)) {
+	    sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,
+		"%s%s is too big to fit in pathbuf", pathbuf, dp->d_name);
 	    continue;
-	memcpy(&pathbuf[sdlen], dp->d_name, d_len + 1); /* copy NUL too */
-	d_len += sdlen;
+	}
 
+	/* Ignore device nodes listed in ignore_devs[]. */
 	for (i = 0; ignore_devs[i] != NULL; i++) {
-	    len = strlen(ignore_devs[i]);
-	    if (ignore_devs[i][len - 1] == '/')
-		len--;
-	    if (d_len == len && strncmp(pathbuf, ignore_devs[i], len) == 0)
+	    if (strcmp(pathbuf, ignore_devs[i]) == 0)
 		break;
 	}
-	if (ignore_devs[i] != NULL)
+	if (ignore_devs[i] != NULL) {
+	    sudo_debug_printf(SUDO_DEBUG_DEBUG|SUDO_DEBUG_LINENO,
+		"ignoring %s", pathbuf);
 	    continue;
-# if defined(HAVE_STRUCT_DIRENT_D_TYPE) && defined(DTTOIF)
+	}
+
+# if defined(HAVE_STRUCT_DIRENT_D_TYPE)
 	/*
 	 * Avoid excessive stat() calls by checking dp->d_type.
 	 */
@@ -248,18 +230,19 @@ sudo_ttyname_scan(const char *dir, dev_t rdev, char *name, size_t namelen)
 	    case DT_CHR:
 	    case DT_LNK:
 	    case DT_UNKNOWN:
-		/* Could be a character device, stat() it. */
-		if (stat(pathbuf, &sb) == -1)
-		    continue;
 		break;
 	    default:
 		/* Not a character device or link, skip it. */
+		sudo_debug_printf(SUDO_DEBUG_DEBUG|SUDO_DEBUG_LINENO,
+		    "skipping non-device %s", pathbuf);
 		continue;
 	}
-# else
-	if (stat(pathbuf, &sb) == -1)
-	    continue;
 # endif
+	if (stat(pathbuf, &sb) == -1) {
+	    sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO|SUDO_DEBUG_ERRNO,
+		"unable to stat %s", pathbuf);
+	    continue;
+	}
 	if (S_ISCHR(sb.st_mode) && sb.st_rdev == rdev) {
 	    sudo_debug_printf(SUDO_DEBUG_INFO|SUDO_DEBUG_LINENO,
 		"resolved dev %u as %s", (unsigned int)rdev, pathbuf);
@@ -281,67 +264,88 @@ done:
     debug_return_str(ret);
 }
 
+static char *
+sudo_dev_check(dev_t rdev, const char *devname, char *buf, size_t buflen)
+{
+    struct stat sb;
+    debug_decl(sudo_dev_check, SUDO_DEBUG_UTIL)
+
+    if (stat(devname, &sb) == 0) {
+	if (S_ISCHR(sb.st_mode) && sb.st_rdev == rdev) {
+	    sudo_debug_printf(SUDO_DEBUG_INFO|SUDO_DEBUG_LINENO,
+		"comparing dev %u to %s: match!",
+		(unsigned int)rdev, devname);
+	    if (strlcpy(buf, devname, buflen) < buflen)
+		debug_return_str(buf);
+	    sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,
+		"unable to store %s, have %zu, need %zu",
+		devname, buflen, strlen(devname) + 1);
+	    errno = ERANGE;
+	}
+    }
+    sudo_debug_printf(SUDO_DEBUG_INFO|SUDO_DEBUG_LINENO,
+	"comparing dev %u to %s: no", (unsigned int)rdev, devname);
+    debug_return_str(NULL);
+}
+
 /*
  * Like ttyname() but uses a dev_t instead of an open fd.
  * Returns name on success and NULL on failure, setting errno.
  * Generic version.
  */
 static char *
-sudo_ttyname_dev(dev_t rdev, char *name, size_t namelen)
+sudo_ttyname_dev(dev_t rdev, char *buf, size_t buflen)
 {
-    char buf[PATH_MAX], **sd, *devname;
-    char *ret = NULL;
-    struct stat sb;
+    const char *devsearch, *devsearch_end;
+    char path[PATH_MAX], *ret;
+    const char *cp, *ep;
     size_t len;
     debug_decl(sudo_ttyname_dev, SUDO_DEBUG_UTIL)
 
     /*
-     * First check search_devs[] for common tty devices.
+     * First, check /dev/console.
      */
-    for (sd = search_devs; (devname = *sd) != NULL; sd++) {
-	len = strlen(devname);
-	if (devname[len - 1] == '/') {
-	    if (strcmp(devname, "/dev/pts/") == 0) {
-		/* Special case /dev/pts */
-		(void)snprintf(buf, sizeof(buf), "%spts/%u", _PATH_DEV,
-		    (unsigned int)minor(rdev));
-		if (stat(buf, &sb) == 0) {
-		    if (S_ISCHR(sb.st_mode) && sb.st_rdev == rdev) {
-			sudo_debug_printf(SUDO_DEBUG_INFO|SUDO_DEBUG_LINENO,
-			    "comparing dev %u to %s: match!",
-			    (unsigned int)rdev, buf);
-			if (strlcpy(name, buf, namelen) < namelen)
-			    ret = name;
-			else
-			    errno = ERANGE;
-			goto done;
-		    }
-		}
-		sudo_debug_printf(SUDO_DEBUG_INFO|SUDO_DEBUG_LINENO,
-		    "comparing dev %u to %s: no", (unsigned int)rdev, buf);
-	    } else {
-		/* Traverse directory */
-		ret = sudo_ttyname_scan(devname, rdev, name, namelen);
-		if (ret != NULL || errno == ENOMEM)
-		    goto done;
-	    }
-	} else {
-	    if (stat(devname, &sb) == 0) {
-		if (S_ISCHR(sb.st_mode) && sb.st_rdev == rdev) {
-		    if (strlcpy(name, devname, namelen) < namelen)
-			ret = name;
-		    else
-			errno = ERANGE;
-		    goto done;
-		}
-	    }
-	}
-    }
+    ret = sudo_dev_check(rdev, "/dev/console", buf, buflen);
+    if (ret != NULL)
+	goto done;
 
     /*
-     * Not found?  Check all device nodes in /dev.
+     * Then check the device search path.
      */
-    ret = sudo_ttyname_scan(_PATH_DEV, rdev, name, namelen);
+    devsearch = sudo_conf_devsearch_path();
+    devsearch_end = devsearch + strlen(devsearch);
+    for (cp = sudo_strsplit(devsearch, devsearch_end, ":", &ep);
+	cp != NULL; cp = sudo_strsplit(NULL, devsearch_end, ":", &ep)) {
+
+	len = (size_t)(ep - cp);
+	if (len >= sizeof(path)) {
+	    sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,
+		"devsearch entry %.*s too long", (int)len, cp);
+	    continue;
+	}
+	memcpy(path, cp, len);
+	path[len] = '\0';
+
+	if (strcmp(path, "/dev/pts") == 0) {
+	    /* Special case /dev/pts */
+	    len = (size_t)snprintf(path, sizeof(path), "/dev/pts/%u",
+		(unsigned int)minor(rdev));
+	    if (len >= sizeof(path)) {
+		sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,
+		    "devsearch entry /dev/pts/%u too long",
+		    (unsigned int)minor(rdev));
+		continue;
+	    }
+	    ret = sudo_dev_check(rdev, path, buf, buflen);
+	    if (ret != NULL)
+		goto done;
+	} else {
+	    /* Scan path, looking for rdev. */
+	    ret = sudo_ttyname_scan(path, rdev, buf, buflen);
+	    if (ret != NULL || errno == ENOMEM)
+		goto done;
+	}
+    }
 
 done:
     debug_return_str(ret);