rpms
/
systemd
2
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

Better fix for the notify message issue

This commit is contained in:
Zbigniew Jędrzejewski-Szmek 2016-09-29 17:04:15 -04:00
parent 20fa848003
commit 3a5d9b71f4
4 changed files with 137 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
0016-If-the-notification-message-length-is-0-ignore-the-m.patch
View File

@ -1,4 +1,4 @@
From d22ed4fb5c503575bc4d62b599d790ebce8cbab4 Mon Sep 17 00:00:00 2001
From 2e9b525caa9e3126e54f0d9506d0c36d7d533997 Mon Sep 17 00:00:00 2001
From: Jorge Niedbalski <jorge.niedbalski@canonical.com>
Date: Wed, 28 Sep 2016 18:25:50 -0300
Subject: [PATCH] If the notification message length is 0, ignore the message
@ -7,6 +7,7 @@ Subject: [PATCH] If the notification message length is 0, ignore the message
Fixes #4234.
Signed-off-by: Jorge Niedbalski <jnr@metaklass.org>
(cherry picked from commit 531ac2b2349da02acc9c382849758e07eb92b020)
---
src/core/manager.c | 4 ++++
1 file changed, 4 insertions(+)

51
0017-pid1-don-t-return-any-error-in-manager_dispatch_noti.patch Normal file
View File

@ -0,0 +1,51 @@
From 39e5e97e68a9c1bca3bcfa6c9316a83dad0b072d Mon Sep 17 00:00:00 2001
From: Franck Bui <fbui@suse.com>
Date: Thu, 29 Sep 2016 19:44:34 +0200
Subject: [PATCH] pid1: don't return any error in manager_dispatch_notify_fd()
(#4240)
If manager_dispatch_notify_fd() fails and returns an error then the handling of
service notifications will be disabled entirely leading to a compromised system.
For example pid1 won't be able to receive the WATCHDOG messages anymore and
will kill all services supposed to send such messages.
(cherry picked from commit 9987750e7a4c62e0eb8473603150596ba7c3a015)
---
src/core/manager.c | 13 +++++++++----
1 file changed, 9 insertions(+), 4 deletions(-)
diff --git a/src/core/manager.c b/src/core/manager.c
index a085ed899a..36488b673a 100644
--- a/src/core/manager.c
+++ b/src/core/manager.c
@@ -1643,10 +1643,14 @@ static int manager_dispatch_notify_fd(sd_event_source *source, int fd, uint32_t
n = recvmsg(m->notify_fd, &msghdr, MSG_DONTWAIT|MSG_CMSG_CLOEXEC);
if (n < 0) {
- if (errno == EAGAIN || errno == EINTR)
- return 0;
+ if (!IN_SET(errno, EAGAIN, EINTR))
+ log_error("Failed to receive notification message: %m");
- return -errno;
+ /* It's not an option to return an error here since it
+ * would disable the notification handler entirely. Services
+ * wouldn't be able to send the WATCHDOG message for
+ * example... */
+ return 0;
}
if (n == 0) {
log_debug("Got zero-length notification message. Ignoring.");
@@ -1673,7 +1677,8 @@ static int manager_dispatch_notify_fd(sd_event_source *source, int fd, uint32_t
r = fdset_new_array(&fds, fd_array, n_fds);
if (r < 0) {
close_many(fd_array, n_fds);
- return log_oom();
+ log_oom();
+ return 0;
}
}
--
2.9.0

80
0018-pid1-process-zero-length-notification-messages-again.patch Normal file
View File

@ -0,0 +1,80 @@
From 9d77c48a80e1cc2ad016eba1756a5ca293d51f86 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Zbigniew=20J=C4=99drzejewski-Szmek?= <zbyszek@in.waw.pl>
Date: Thu, 29 Sep 2016 16:06:02 +0200
Subject: [PATCH] pid1: process zero-length notification messages again
This undoes 531ac2b234. I acked that patch without looking at the code
carefully enough. There are two problems:
- we want to process the fds anyway
- in principle empty notification messages are valid, and we should
process them as usual, including logging using log_unit_debug().
(cherry picked from commit 8523bf7dd514a3a2c6114b7b8fb8f308b4f09fc4)
---
src/core/manager.c | 15 ++++++---------
1 file changed, 6 insertions(+), 9 deletions(-)
diff --git a/src/core/manager.c b/src/core/manager.c
index 36488b673a..85bf858992 100644
--- a/src/core/manager.c
+++ b/src/core/manager.c
@@ -1584,13 +1584,12 @@ static int manager_dispatch_cgroups_agent_fd(sd_event_source *source, int fd, ui
return 0;
}
-static void manager_invoke_notify_message(Manager *m, Unit *u, pid_t pid, const char *buf, size_t n, FDSet *fds) {
+static void manager_invoke_notify_message(Manager *m, Unit *u, pid_t pid, const char *buf, FDSet *fds) {
_cleanup_strv_free_ char **tags = NULL;
assert(m);
assert(u);
assert(buf);
- assert(n > 0);
tags = strv_split(buf, "\n\r");
if (!tags) {
@@ -1652,10 +1651,6 @@ static int manager_dispatch_notify_fd(sd_event_source *source, int fd, uint32_t
* example... */
return 0;
}
- if (n == 0) {
- log_debug("Got zero-length notification message. Ignoring.");
- return 0;
- }
CMSG_FOREACH(cmsg, &msghdr) {
if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_RIGHTS) {
@@ -1692,25 +1687,27 @@ static int manager_dispatch_notify_fd(sd_event_source *source, int fd, uint32_t
return 0;
}
+ /* The message should be a string. Here we make sure it's NUL-terminated,
+ * but only the part until first NUL will be used anyway. */
buf[n] = 0;
/* Notify every unit that might be interested, but try
* to avoid notifying the same one multiple times. */
u1 = manager_get_unit_by_pid_cgroup(m, ucred->pid);
if (u1) {
- manager_invoke_notify_message(m, u1, ucred->pid, buf, n, fds);
+ manager_invoke_notify_message(m, u1, ucred->pid, buf, fds);
found = true;
}
u2 = hashmap_get(m->watch_pids1, PID_TO_PTR(ucred->pid));
if (u2 && u2 != u1) {
- manager_invoke_notify_message(m, u2, ucred->pid, buf, n, fds);
+ manager_invoke_notify_message(m, u2, ucred->pid, buf, fds);
found = true;
}
u3 = hashmap_get(m->watch_pids2, PID_TO_PTR(ucred->pid));
if (u3 && u3 != u2 && u3 != u1) {
- manager_invoke_notify_message(m, u3, ucred->pid, buf, n, fds);
+ manager_invoke_notify_message(m, u3, ucred->pid, buf, fds);
found = true;
}
--
2.9.0

5
systemd.spec
View File

@ -12,7 +12,7 @@
Name: systemd
Url: http://www.freedesktop.org/wiki/Software/systemd
Version: 231
Release: 5%{?gitcommit:.git%{gitcommitshort}}%{?dist}
Release: 6%{?gitcommit:.git%{gitcommitshort}}%{?dist}
# For a breakdown of the licensing, see README
License: LGPLv2+ and MIT and GPLv2+
Summary: A System and Service Manager
@ -946,6 +946,9 @@ getent passwd systemd-journal-upload >/dev/null 2>&1 || useradd -r -l -g systemd
%{_mandir}/man[1578]/systemd-nspawn.*
%changelog
* Thu Sep 29 2016 Zbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl> - 231-6
- Better fix for (#1380286)
* Thu Sep 29 2016 Zbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl> - 231-5
- Denial-of-service bug against pid1 (#1380286)