From: Franck Bui Date: Thu, 29 Sep 2016 11:59:49 +0200 Subject: [PATCH 1/1] pid1: don't return any error in manager_dispatch_notify_fd() 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. --- 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 43e231c..5704005 100644 --- a/src/core/manager.c +++ b/src/core/manager.c @@ -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; } } -- 2.10.0