From c3a8638cf447ae5901dccb89ea766d768febe529 Mon Sep 17 00:00:00 2001

From: Colin Guthrie <colin@mageia.org>

Date: Wed, 29 Oct 2014 14:03:41 +0000

Subject: [PATCH] sysusers: Preserve ownership and mode on /etc/passwd and

 friends

When running sysusers we would clobber file ownership and permissions

on the files /etc/passwd, /etc/group and /etc/[g]shadow.

This simply preserves the ownership and mode if existing files are

found.

(cherry picked from commit e3c72c21d62aadabf4df436c3e2c7219eeeccc1c)

---

 src/sysusers/sysusers.c | 61 +++++++++++++++++++++++++++++++++----------------

 1 file changed, 41 insertions(+), 20 deletions(-)

diff --git a/src/sysusers/sysusers.c b/src/sysusers/sysusers.c

index 9b9be96a0a..c133dc5f10 100644

--- a/src/sysusers/sysusers.c

+++ b/src/sysusers/sysusers.c

@@ -358,6 +358,7 @@ static int write_files(void) {

         _cleanup_fclose_ FILE *passwd = NULL, *group = NULL, *shadow = NULL, *gshadow = NULL;

         _cleanup_free_ char *passwd_tmp = NULL, *group_tmp = NULL, *shadow_tmp = NULL, *gshadow_tmp = NULL;

         const char *passwd_path = NULL, *group_path = NULL, *shadow_path = NULL, *gshadow_path = NULL;

+        struct stat st;

         bool group_changed = false;

         Iterator iterator;

         Item *i;

@@ -372,15 +373,17 @@ static int write_files(void) {

                 if (r < 0)

                         goto finish;

-                if (fchmod(fileno(group), 0644) < 0) {

-                        r = -errno;

-                        goto finish;

-                }

-

                 original = fopen(group_path, "re");

                 if (original) {

                         struct group *gr;

+                        if (fstat(fileno(original), &st) < 0 ||

+                            fchmod(fileno(group), st.st_mode & 07777) < 0 ||

+                            fchown(fileno(group), st.st_uid, st.st_gid) < 0) {

+                                r = -errno;

+                                goto finish;

+                        }

+

                         errno = 0;

                         while ((gr = fgetgrent(original))) {

                                 /* Safety checks against name and GID

@@ -418,6 +421,9 @@ static int write_files(void) {

                 } else if (errno != ENOENT) {

                         r = -errno;

                         goto finish;

+                } else if (fchmod(fileno(group), 0644) < 0) {

+                        r = -errno;

+                        goto finish;

                 }

                 HASHMAP_FOREACH(i, todo_gids, iterator) {

@@ -449,15 +455,17 @@ static int write_files(void) {

                 if (r < 0)

                         goto finish;

-                if (fchmod(fileno(gshadow), 0000) < 0) {

-                        r = -errno;

-                        goto finish;

-                }

-

                 original = fopen(gshadow_path, "re");

                 if (original) {

                         struct sgrp *sg;

+                        if (fstat(fileno(original), &st) < 0 ||

+                            fchmod(fileno(gshadow), st.st_mode & 07777) < 0 ||

+                            fchown(fileno(gshadow), st.st_uid, st.st_gid) < 0) {

+                                r = -errno;

+                                goto finish;

+                        }

+

                         errno = 0;

                         while ((sg = fgetsgent(original))) {

@@ -483,6 +491,9 @@ static int write_files(void) {

                 } else if (errno != ENOENT) {

                         r = -errno;

                         goto finish;

+                } else if (fchmod(fileno(gshadow), 0000) < 0) {

+                        r = -errno;

+                        goto finish;

                 }

                 HASHMAP_FOREACH(i, todo_gids, iterator) {

@@ -513,15 +524,17 @@ static int write_files(void) {

                 if (r < 0)

                         goto finish;

-                if (fchmod(fileno(passwd), 0644) < 0) {

-                        r = -errno;

-                        goto finish;

-                }

-

                 original = fopen(passwd_path, "re");

                 if (original) {

                         struct passwd *pw;

+                        if (fstat(fileno(original), &st) < 0 ||

+                            fchmod(fileno(passwd), st.st_mode & 07777) < 0 ||

+                            fchown(fileno(passwd), st.st_uid, st.st_gid) < 0) {

+                                r = -errno;

+                                goto finish;

+                        }

+

                         errno = 0;

                         while ((pw = fgetpwent(original))) {

@@ -552,6 +565,9 @@ static int write_files(void) {

                 } else if (errno != ENOENT) {

                         r = -errno;

                         goto finish;

+                } else if (fchmod(fileno(passwd), 0644) < 0) {

+                        r = -errno;

+                        goto finish;

                 }

                 HASHMAP_FOREACH(i, todo_uids, iterator) {

@@ -596,15 +612,17 @@ static int write_files(void) {

                 if (r < 0)

                         goto finish;

-                if (fchmod(fileno(shadow), 0000) < 0) {

-                        r = -errno;

-                        goto finish;

-                }

-

                 original = fopen(shadow_path, "re");

                 if (original) {

                         struct spwd *sp;

+                        if (fstat(fileno(original), &st) < 0 ||

+                            fchmod(fileno(shadow), st.st_mode & 07777) < 0 ||

+                            fchown(fileno(shadow), st.st_uid, st.st_gid) < 0) {

+                                r = -errno;

+                                goto finish;

+                        }

+

                         errno = 0;

                         while ((sp = fgetspent(original))) {

@@ -629,6 +647,9 @@ static int write_files(void) {

                 } else if (errno != ENOENT) {

                         r = -errno;

                         goto finish;

+                } else if (fchmod(fileno(shadow), 0000) < 0) {

+                        r = -errno;

+                        goto finish;

                 }

                 lstchg = (long) (now(CLOCK_REALTIME) / USEC_PER_DAY);