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.
This commit is contained in:
Franck Bui 2016-09-29 19:44:34 +02:00 committed by Zbigniew Jędrzejewski-Szmek
parent 531ac2b234
commit 9987750e7a
1 changed files with 9 additions and 4 deletions

View File

@ -1716,10 +1716,14 @@ 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.");
@ -1746,7 +1750,8 @@ 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;
}
}