From 0356607264b8e1476d98a81667488ba1d6295d23 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?S=C3=B6ren=20Tempel?= Date: Tue, 9 Jun 2020 17:51:26 +0200 Subject: [PATCH] deluser: check if specified home is a directory before removing it MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit On Alpine, some users use /dev/null as a home directory. When removing such a user with `deluser --remove-home` this causes the /dev/null device file to be removed which is undesirable. To prevent this pitfall, check if the home directory specified for the user is an actual directory (or a symlink to a directory). Implementations of similar tools for other operating systems also implement such checks. For instance, the OpenBSD rmuser(1) implementation [0]. [0]: https://github.com/openbsd/src/blob/b69faa6c70c5bfcfdddc6138cd8e0ee18cc15b03/usr.sbin/adduser/rmuser.perl#L143-L151 function old new delta deluser_main 337 380 +43 Signed-off-by: Sören Tempel Signed-off-by: Denys Vlasenko --- loginutils/deluser.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/loginutils/deluser.c b/loginutils/deluser.c index 56bc7eaa6..8e7df737c 100644 --- a/loginutils/deluser.c +++ b/loginutils/deluser.c @@ -99,8 +99,14 @@ int deluser_main(int argc, char **argv) pfile = bb_path_passwd_file; if (ENABLE_FEATURE_SHADOWPASSWDS) sfile = bb_path_shadow_file; - if (opt_delhome) - remove_file(pw->pw_dir, FILEUTILS_RECUR); + if (opt_delhome) { + struct stat st; + + /* Make sure home is an actual directory before + * removing it (e.g. users with /dev/null as home) */ + if (stat(pw->pw_dir, &st) == 0 && S_ISDIR(st.st_mode)) + remove_file(pw->pw_dir, FILEUTILS_RECUR); + } } else { struct group *gr; do_delgroup: