Check the return value of the fchdir() system call

dtach was not checking if the fchdir back to the old directory worked
when it tried to get around the sun_path length limit.

2 files changed, 15 insertions, 3 deletions

diff --git a/attach.c b/attach.c
index 5fd301c..8ac3bf3 100644
--- a/attach.c
+++ b/attach.c
@@ -170,7 +170,11 @@ attach_main(int noerror)
 				if (chdir(sockname) >= 0)
 				{
 					s = connect_socket(slash + 1);
-					fchdir(dirfd);
+					if (s >= 0 && fchdir(dirfd) < 0)
+					{
+						close(s);
+						s = -1;
+					}
 				}
 				*slash = '/';
 				close(dirfd);
@@ -315,7 +319,11 @@ push_main()
 				if (chdir(sockname) >= 0)
 				{
 					s = connect_socket(slash + 1);
-					fchdir(dirfd);
+					if (s >= 0 && fchdir(dirfd) < 0)
+					{
+						close(s);
+						s = -1;
+					}
 				}
 				*slash = '/';
 				close(dirfd);
diff --git a/master.c b/master.c
index 3755f65..81aa6a9 100644
--- a/master.c
+++ b/master.c
@@ -594,7 +594,11 @@ master_main(char **argv, int waitattach, int dontfork)
 				if (chdir(sockname) >= 0)
 				{
 					s = create_socket(slash + 1);
-					fchdir(dirfd);
+					if (s >= 0 && fchdir(dirfd) < 0)
+					{
+						close(s);
+						s = -1;
+					}
 				}
 				*slash = '/';
 				close(dirfd);