upstream: Replace all calls to signal(2) with a wrapper around

sigaction(2). This wrapper blocks all other signals during the handler
preventing races between handlers, and sets SA_RESTART which should reduce
the potential for short read/write operations.

OpenBSD-Commit-ID: 5e047663fd77a40d7b07bdabe68529df51fd2519

1 files changed, 5 insertions, 4 deletions

diff --git a/ssh-sk-client.c b/ssh-sk-client.c
index 359327b68..8d7e6c305 100644
--- a/ssh-sk-client.c
+++ b/ssh-sk-client.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssh-sk-client.c,v 1.6 2020/01/21 07:07:31 djm Exp $ */
+/* $OpenBSD: ssh-sk-client.c,v 1.7 2020/01/23 07:10:22 dtucker Exp $ */
 /*
  * Copyright (c) 2019 Google LLC
  *
@@ -39,6 +39,7 @@
 #include "digest.h"
 #include "pathnames.h"
 #include "ssh-sk.h"
+#include "misc.h"
 
 /* #define DEBUG_SK 1 */
 
@@ -73,13 +74,13 @@ start_helper(int *fdp, pid_t *pidp, void (**osigchldp)(int))
                 error("socketpair: %s", strerror(errno));
                 return SSH_ERR_SYSTEM_ERROR;
         }
-        osigchld = signal(SIGCHLD, SIG_DFL);
+        osigchld = ssh_signal(SIGCHLD, SIG_DFL);
         if ((pid = fork()) == -1) {
                 oerrno = errno;
                 error("fork: %s", strerror(errno));
                 close(pair[0]);
                 close(pair[1]);
-                signal(SIGCHLD, osigchld);
+                ssh_signal(SIGCHLD, osigchld);
                 errno = oerrno;
                 return SSH_ERR_SYSTEM_ERROR;
         }
@@ -220,7 +221,7 @@ client_converse(struct sshbuf *msg, struct sshbuf **respp, u_int type)
         }
         sshbuf_free(req);
         sshbuf_free(resp);
-        signal(SIGCHLD, osigchld);
+        ssh_signal(SIGCHLD, osigchld);
         errno = oerrno;
         return r;