From 085d04c3ddfb817ba5f13269b604384c260be84f Mon Sep 17 00:00:00 2001 From: Duncan Overbruck Date: Sat, 11 Jan 2020 22:19:37 +0100 Subject: [PATCH] add new HOME_MODE login.defs(5) option This option can be used to set a separate mode for useradd(8) and newusers(8) to create the home directories with. If this option is not set, the current behavior of using UMASK or the default umask is preserved. There are many distributions that set UMASK to 077 by default just to create home directories not readable by others and use things like /etc/profile, bashrc or sudo configuration files to set a less restrictive umask. This has always resulted in bug reports because it is hard to follow as users tend to change files like bashrc and are not about setting the umask to counteract the umask set in /etc/login.defs. A recent change in sudo has also resulted in many bug reports about this. sudo now tries to respect the umask set by pam modules and on systems where pam does not set a umask, the login.defs UMASK value is used. --- etc/login.defs | 7 +++++- lib/getdef.c | 1 + man/login.defs.5.xml | 4 ++++ man/login.defs.d/HOME_MODE.xml | 43 ++++++++++++++++++++++++++++++++++ man/login.defs.d/UMASK.xml | 3 ++- man/newusers.8.xml | 2 ++ man/useradd.8.xml | 2 ++ src/newusers.c | 6 ++--- src/useradd.c | 5 ++-- 9 files changed, 66 insertions(+), 7 deletions(-) create mode 100644 man/login.defs.d/HOME_MODE.xml diff --git a/etc/login.defs b/etc/login.defs index cd2597dc..a2f8cd50 100644 --- a/etc/login.defs +++ b/etc/login.defs @@ -195,12 +195,17 @@ KILLCHAR 025 # Default initial "umask" value used by login(1) on non-PAM enabled systems. # Default "umask" value for pam_umask(8) on PAM enabled systems. # UMASK is also used by useradd(8) and newusers(8) to set the mode for new -# home directories. +# home directories if HOME_MODE is not set. # 022 is the default value, but 027, or even 077, could be considered # for increased privacy. There is no One True Answer here: each sysadmin # must make up their mind. UMASK 022 +# HOME_MODE is used by useradd(8) and newusers(8) to set the mode for new +# home directories. +# If HOME_MODE is not set, the value of UMASK is used to create the mode. +#HOME_MODE 0700 + # # Password aging controls: # diff --git a/lib/getdef.c b/lib/getdef.c index bbb273f4..00f6abfe 100644 --- a/lib/getdef.c +++ b/lib/getdef.c @@ -93,6 +93,7 @@ static struct itemdef def_table[] = { {"FAKE_SHELL", NULL}, {"GID_MAX", NULL}, {"GID_MIN", NULL}, + {"HOME_MODE", NULL}, {"HUSHLOGIN_FILE", NULL}, {"KILLCHAR", NULL}, {"LASTLOG_UID_MAX", NULL}, diff --git a/man/login.defs.5.xml b/man/login.defs.5.xml index ebf60ba3..9e95da20 100644 --- a/man/login.defs.5.xml +++ b/man/login.defs.5.xml @@ -50,6 +50,7 @@ + @@ -185,6 +186,7 @@ &FAKE_SHELL; &FTMP_FILE; &GID_MAX; + &HOME_MODE; &HUSHLOGIN_FILE; &ISSUE_FILE; &KILLCHAR; @@ -401,6 +403,7 @@ ENCRYPT_METHOD GID_MAX GID_MIN MAX_MEMBERS_PER_GROUP MD5_CRYPT_ENAB + HOME_MODE PASS_MAX_DAYS PASS_MIN_DAYS PASS_WARN_AGE SHA_CRYPT_MAX_ROUNDS SHA_CRYPT_MIN_ROUNDS @@ -481,6 +484,7 @@ CREATE_HOME GID_MAX GID_MIN + HOME_MODE LASTLOG_UID_MAX MAIL_DIR MAX_MEMBERS_PER_GROUP PASS_MAX_DAYS PASS_MIN_DAYS PASS_WARN_AGE diff --git a/man/login.defs.d/HOME_MODE.xml b/man/login.defs.d/HOME_MODE.xml new file mode 100644 index 00000000..21aa55f7 --- /dev/null +++ b/man/login.defs.d/HOME_MODE.xml @@ -0,0 +1,43 @@ + + + (number) + + + The mode for new home directories. If not specified, + the is used to create the mode. + + + useradd and newusers use this + to set the mode of the home directory they create. + + + diff --git a/man/login.defs.d/UMASK.xml b/man/login.defs.d/UMASK.xml index d7b71a5e..0f061dbb 100644 --- a/man/login.defs.d/UMASK.xml +++ b/man/login.defs.d/UMASK.xml @@ -37,7 +37,8 @@ useradd and newusers use this - mask to set the mode of the home directory they create + mask to set the mode of the home directory they create if + is not set. It is also used by login to define users' initial diff --git a/man/newusers.8.xml b/man/newusers.8.xml index a1029a27..13307cc1 100644 --- a/man/newusers.8.xml +++ b/man/newusers.8.xml @@ -32,6 +32,7 @@ "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd" [ + @@ -382,6 +383,7 @@ &GID_MAX; + &HOME_MODE; &MAX_MEMBERS_PER_GROUP; diff --git a/man/useradd.8.xml b/man/useradd.8.xml index a16d7307..03612ce8 100644 --- a/man/useradd.8.xml +++ b/man/useradd.8.xml @@ -32,6 +32,7 @@ "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd" [ + @@ -681,6 +682,7 @@ &CREATE_HOME; &GID_MAX; + &HOME_MODE; &LASTLOG_UID_MAX; &MAIL_DIR; &MAX_MEMBERS_PER_GROUP; diff --git a/src/newusers.c b/src/newusers.c index 99c69f78..e9fe0e27 100644 --- a/src/newusers.c +++ b/src/newusers.c @@ -1216,9 +1216,9 @@ int main (int argc, char **argv) if ( ('\0' != fields[5][0]) && (access (newpw.pw_dir, F_OK) != 0)) { /* FIXME: should check for directory */ - mode_t msk = 0777 & ~getdef_num ("UMASK", - GETDEF_DEFAULT_UMASK); - if (mkdir (newpw.pw_dir, msk) != 0) { + mode_t mode = getdef_num ("HOME_MODE", + 0777 & ~getdef_num ("UMASK", GETDEF_DEFAULT_UMASK)); + if (mkdir (newpw.pw_dir, mode) != 0) { fprintf (stderr, _("%s: line %d: mkdir %s failed: %s\n"), Prog, line, newpw.pw_dir, diff --git a/src/useradd.c b/src/useradd.c index 62e57a4f..c29ae949 100644 --- a/src/useradd.c +++ b/src/useradd.c @@ -2155,8 +2155,9 @@ static void create_home (void) } (void) chown (prefix_user_home, user_id, user_gid); - chmod (prefix_user_home, - 0777 & ~getdef_num ("UMASK", GETDEF_DEFAULT_UMASK)); + mode_t mode = getdef_num ("HOME_MODE", + 0777 & ~getdef_num ("UMASK", GETDEF_DEFAULT_UMASK)); + chmod (prefix_user_home, mode); home_added = true; #ifdef WITH_AUDIT audit_logger (AUDIT_ADD_USER, Prog,