busybox: backport sulogin empty root password fix

This allows system maintenance login if the root password is empty.

(From OE-Core rev: 28bb8fe5c144e02c28bff54b5b81c8da33b9f58b)

Signed-off-by: Jonathan Liu <net147@gmail.com>
Signed-off-by: Saul Wold <sgw@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

2 files changed, 59 insertions, 0 deletions

diff --git a/meta/recipes-core/busybox/busybox-1.20.2/busybox-sulogin-empty-root-password.patch b/meta/recipes-core/busybox/busybox-1.20.2/busybox-sulogin-empty-root-password.patch
new file mode 100644
index 0000000000..baad298a3f
--- /dev/null
+++ b/meta/recipes-core/busybox/busybox-1.20.2/busybox-sulogin-empty-root-password.patch
@@ -0,0 +1,58 @@
+Upstream-Status: Backport
+Signed-off-by: Jonathan Liu <net147@gmail.com>
+
+From b6dc13c2d3754704b1bf5af4e6b957b48585102f Mon Sep 17 00:00:00 2001
+From: Jonathan Liu <net147@gmail.com>
+Date: Tue, 21 May 2013 17:01:55 +0200
+Subject: [PATCH] sulogin: allow system maintenance login if root password is
+ empty
+
+The current password checking is unable to distinguish between the user
+entering an empty password or pressing Control-D. As a result, an empty
+password always results in normal startup.
+
+We modify bb_ask to return NULL if Control-D is pressed without entering
+a password. The sulogin applet is then modified to only proceed to
+normal startup if bb_ask returns NULL. This covers EOF with no password,
+interrupt by timeout and ^C.
+
+Signed-off-by: Jonathan Liu <net147@gmail.com>
+Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
+---
+ libbb/bb_askpass.c   | 4 +++-
+ loginutils/sulogin.c | 4 ++--
+ 2 files changed, 5 insertions(+), 3 deletions(-)
+
+diff --git a/libbb/bb_askpass.c b/libbb/bb_askpass.c
+index fe2b506..77c1bcd 100644
+--- a/libbb/bb_askpass.c
++++ b/libbb/bb_askpass.c
+@@ -65,7 +65,9 @@ char* FAST_FUNC bb_ask(const int fd, int timeout, const char *prompt)
+        i = 0;
+        while (1) {
+                int r = read(fd, &ret[i], 1);
+-               if (r < 0) {
++               if ((i == 0 && r == 0) /* EOF (^D) with no password */
++                || r < 0
++               ) {
+                        /* read is interrupted by timeout or ^C */
+                        ret = NULL;
+                        break;
+diff --git a/loginutils/sulogin.c b/loginutils/sulogin.c
+index f79802a..65e6384 100644
+--- a/loginutils/sulogin.c
++++ b/loginutils/sulogin.c
+@@ -83,8 +83,8 @@ int sulogin_main(int argc UNUSED_PARAM, char **argv)
+                cp = bb_ask(STDIN_FILENO, timeout,
+                                "Give root password for system maintenance\n"
+                                "(or type Control-D for normal startup):");
+-
+-               if (!cp || !*cp) {
++               if (!cp) {
++                       /* ^D, ^C, timeout, or read error */
+                        bb_info_msg("Normal startup");
+                        return 0;
+                }
+-- 
+1.8.2.3
+
diff --git a/meta/recipes-core/busybox/busybox_1.20.2.bb b/meta/recipes-core/busybox/busybox_1.20.2.bb
index 1445a5e46c..07d722d722 100644
--- a/meta/recipes-core/busybox/busybox_1.20.2.bb
+++ b/meta/recipes-core/busybox/busybox_1.20.2.bb
@@ -33,6 +33,7 @@ SRC_URI = "http://www.busybox.net/downloads/busybox-${PV}.tar.bz2;name=tarball \
            file://testsuite-du-du-k-works-fix-false-positive.patch \
            file://strict-atime.patch \
            file://fail_on_no_media.patch \
+           file://busybox-sulogin-empty-root-password.patch \
            file://inetd.conf \
            file://inetd"