Dominique Leuenberger 2021-11-09 22:53:49 +00:00 committed by Git OBS Bridge
commit bf48957367
3 changed files with 96 additions and 0 deletions

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@ -0,0 +1,75 @@
From 44ed6a1724bac01cd1c1dd25defb62237df5f379 Mon Sep 17 00:00:00 2001
From: Thomas Haller <thaller@redhat.com>
Date: Fri, 21 May 2021 18:32:07 +0200
Subject: [PATCH 1/1] teamd: better handle failures to chown(TEAMD_RUN_DIR)
during teamd_drop_privileges()
NetworkManager is exec-ing teamd while running without CAP_CHOWN.
When teamd is configured to drop privileges, then it will call chown
while still running as root user. But the command will fail because of
lack of CAP_CHOWN.
Note that chown() succeeds if the calling process has CAP_CHOWN or if
the file already is owned by the calling user/group (whereas, changing
the group will still work, if the user is a member of that group).
The directory might have already been prepared with the right user/group.
Let's handle that. If the first chown() as root succeeds, we are good.
If it fails, we will retry after changing the user id. If the directory
already has the right/compatible user, this command will succeeds too
and teamd can proceed.
See-also: https://gitlab.freedesktop.org/NetworkManager/NetworkManager/-/issues/722
Signed-off-by: Thomas Haller <thaller@redhat.com>
---
teamd/teamd.c | 18 +++++++++++++-----
1 file changed, 13 insertions(+), 5 deletions(-)
diff --git a/teamd/teamd.c b/teamd/teamd.c
index b310140570c5..3ef3d6cf09f6 100644
--- a/teamd/teamd.c
+++ b/teamd/teamd.c
@@ -1714,6 +1714,7 @@ static int teamd_drop_privileges()
cap_t my_caps;
struct passwd *pw = NULL;
struct group *grpent = NULL;
+ int chown_succeeded;
if ((pw = getpwnam(TEAMD_USER)) == NULL) {
fprintf(stderr, "Error reading user %s entry (%m)\n", TEAMD_USER);
@@ -1734,11 +1735,12 @@ static int teamd_drop_privileges()
goto error;
}
- if (chown(TEAMD_RUN_DIR, pw->pw_uid, pw->pw_gid) < 0) {
- fprintf(stderr, "Unable to change ownership of %s to %s/%s (%m)\n",
- TEAMD_RUN_DIR, TEAMD_USER, TEAMD_GROUP);
- goto error;
- }
+ /* Try to change owner while still being root. We might not have
+ * capabilities, so this might fail. At this point, we accept that,
+ * because the directory might have been prepared with a suitable owner
+ * already. But on failure, we will retry as the new user below.
+ */
+ chown_succeeded = (chown(TEAMD_RUN_DIR, pw->pw_uid, pw->pw_gid) == 0);
if (prctl(PR_SET_KEEPCAPS, 1, 0, 0, 0) < 0)
goto error;
@@ -1758,6 +1760,12 @@ static int teamd_drop_privileges()
goto error;
}
+ if (!chown_succeeded && chown(TEAMD_RUN_DIR, pw->pw_uid, pw->pw_gid) < 0) {
+ fprintf(stderr, "Unable to change ownership of %s to %s/%s (%m)\n",
+ TEAMD_RUN_DIR, TEAMD_USER, TEAMD_GROUP);
+ goto error;
+ }
+
if ((my_caps = cap_init()) == NULL)
goto error;
if (cap_set_flag(my_caps, CAP_EFFECTIVE, ARRAY_SIZE(cv), cv, CAP_SET) < 0)
--
2.31.1

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@ -1,3 +1,10 @@
-------------------------------------------------------------------
Fri Nov 5 17:14:17 UTC 2021 - Otto Hollmann <otto.hollmann@suse.com>
- teamd: better handle failures to chown(TEAMD_RUN_DIR) during
teamd_drop_privileges() (bsc#1185424)
[+ better_handle_failures_to_chown.patch]
------------------------------------------------------------------- -------------------------------------------------------------------
Fri Oct 15 07:32:26 UTC 2021 - Johannes Segitz <jsegitz@suse.com> Fri Oct 15 07:32:26 UTC 2021 - Johannes Segitz <jsegitz@suse.com>

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@ -17,6 +17,8 @@
%bcond_without python2 %bcond_without python2
# _tmpfilesdir is not defined in systemd macros up to openSUSE 13.2
%{!?_tmpfilesdir: %global _tmpfilesdir %{_libexecdir}/tmpfiles.d }
Name: libteam Name: libteam
Version: 1.31 Version: 1.31
Release: 0 Release: 0
@ -32,6 +34,7 @@ Patch2: start_teamd_from_usr_sbin.patch
Patch3: ignore_ebusy_for_team_hwaddr_set.patch Patch3: ignore_ebusy_for_team_hwaddr_set.patch
Patch4: 0001-allow-send_interface-dbus.patch Patch4: 0001-allow-send_interface-dbus.patch
Patch5: harden_teamd@.service.patch Patch5: harden_teamd@.service.patch
Patch6: better_handle_failures_to_chown.patch
BuildRequires: doxygen BuildRequires: doxygen
BuildRequires: libcap-devel BuildRequires: libcap-devel
BuildRequires: libtool BuildRequires: libtool
@ -145,6 +148,14 @@ python ./setup.py install --root="$b" --prefix="%_prefix"
popd popd
%endif %endif
# Install /usr/lib/tmpfiles.d/libteam.conf
mkdir -p %{buildroot}%{_tmpfilesdir}
cat > %{buildroot}%{_tmpfilesdir}/libteam.conf <<EOF
# See tmpfiles.d(5) for details
# Type(d=directory) Path Mode UID GID Age(until delete when cleaning)
d %teamd_daemon_directory 0755 %teamd_user %teamd_group -
EOF
rm -f "$b/%_libdir"/*.la rm -f "$b/%_libdir"/*.la
%if 0%{?_unitdir:1} %if 0%{?_unitdir:1}
mkdir -p "$b/%_unitdir" mkdir -p "$b/%_unitdir"
@ -168,6 +179,8 @@ test -L %teamd_daemon_directory || rm -rf %teamd_daemon_directory && :
%endif %endif
%post tools %post tools
# Use %%tmpfiles_create when 13.2 is oldest in support scope
/usr/bin/systemd-tmpfiles --create %{_tmpfilesdir}/libteam.conf || :
# reload dbus to apply new teamd's policy # reload dbus to apply new teamd's policy
systemctl reload dbus.service 2>/dev/null || : systemctl reload dbus.service 2>/dev/null || :
%if 0%{?_unitdir:1} %if 0%{?_unitdir:1}
@ -217,6 +230,7 @@ fi
%if 0%{?_unitdir:1} %if 0%{?_unitdir:1}
%_unitdir %_unitdir
%endif %endif
%{_tmpfilesdir}/libteam.conf
%if %{with python2} %if %{with python2}
%files -n python-libteam %files -n python-libteam