2 files changed, 35 insertions, 1 deletions

diff --git a/lib/libc/gen/wordexp.c b/lib/libc/gen/wordexp.c
index f1437e30bbe2..f8080c20d121 100644
--- a/lib/libc/gen/wordexp.c
+++ b/lib/libc/gen/wordexp.c
@@ -265,7 +265,15 @@ cleanup:
 		errno = serrno;
 		return (error);
 	}
-	if (wpid < 0 || !WIFEXITED(status) || WEXITSTATUS(status) != 0)
+	/*
+	 * Check process exit status, but ignore ECHILD as the child may have
+	 * been automatically reaped if the process had set SIG_IGN or
+	 * SA_NOCLDWAIT for SIGCHLD, and our reason for waitpid was just to
+	 * reap our own child on behalf of the calling process.
+	 */
+	if (wpid < 0 && errno != ECHILD)
+		return (WRDE_NOSPACE); /* abort for unknown reason */
+	if (wpid >= 0 && (!WIFEXITED(status) || WEXITSTATUS(status) != 0))
 		return (WRDE_NOSPACE); /* abort for unknown reason */
 
 	/*
diff --git a/lib/libc/tests/gen/wordexp_test.c b/lib/libc/tests/gen/wordexp_test.c
index 909097fbf51e..a8b9d5509633 100644
--- a/lib/libc/tests/gen/wordexp_test.c
+++ b/lib/libc/tests/gen/wordexp_test.c
@@ -292,6 +292,31 @@ ATF_TC_BODY(with_SIGCHILD_handler_test, tc)
 	ATF_REQUIRE(r == 0);
 }
 
+ATF_TC_WITHOUT_HEAD(with_SIGCHILD_ignore_test);
+ATF_TC_BODY(with_SIGCHILD_ignore_test, tc)
+{
+	struct sigaction sa;
+	wordexp_t we;
+	int r;
+
+	/* With SIGCHLD set to ignore so that the kernel auto-reaps zombies. */
+	sa.sa_flags = 0;
+	sigemptyset(&sa.sa_mask);
+	sa.sa_handler = SIG_IGN;
+	r = sigaction(SIGCHLD, &sa, NULL);
+	ATF_REQUIRE(r == 0);
+	r = wordexp("hello world", &we, 0);
+	ATF_REQUIRE(r == 0);
+	ATF_REQUIRE(we.we_wordc == 2);
+	ATF_REQUIRE(strcmp(we.we_wordv[0], "hello") == 0);
+	ATF_REQUIRE(strcmp(we.we_wordv[1], "world") == 0);
+	ATF_REQUIRE(we.we_wordv[2] == NULL);
+	wordfree(&we);
+	sa.sa_handler = SIG_DFL;
+	r = sigaction(SIGCHLD, &sa, NULL);
+	ATF_REQUIRE(r == 0);
+}
+
 ATF_TC_WITHOUT_HEAD(with_unused_non_default_IFS_test);
 ATF_TC_BODY(with_unused_non_default_IFS_test, tc)
 {
@@ -350,6 +375,7 @@ ATF_TP_ADD_TCS(tp)
 	ATF_TP_ADD_TC(tp, WRDE_BADCHAR_test);
 	ATF_TP_ADD_TC(tp, WRDE_SYNTAX_test);
 	ATF_TP_ADD_TC(tp, with_SIGCHILD_handler_test);
+	ATF_TP_ADD_TC(tp, with_SIGCHILD_ignore_test);
 	ATF_TP_ADD_TC(tp, with_unused_non_default_IFS_test);
 	ATF_TP_ADD_TC(tp, with_used_non_default_IFS_test);