libfuse: fix multiple close of device fd

- fuse_kern_unmount closes handle (e.g. 19)
- a thread in my process opens a file - the OS assigns newly freed
handle (i.e. 19)
- fuse_kern_chan_destroy closes the same handle (i.e. 19)
- a thread in my process opens another file - the OS assigns newly
freed handle (i.e. 19)
- * MAYHEM *

Reported by Dan Greenfield

1 files changed, 6 insertions, 3 deletions

diff --git a/lib/mount_bsd.c b/lib/mount_bsd.c
index 9ee74fb..36c5a2b 100644
--- a/lib/mount_bsd.c
+++ b/lib/mount_bsd.c
@@ -228,18 +228,21 @@ void fuse_kern_unmount(const char *mountpoint, int fd)
 	(void)mountpoint;
 
 	if (fstat(fd, &sbuf) == -1)
-		return;
+		goto out;
 
 	devname_r(sbuf.st_rdev, S_IFCHR, dev, 128);
 
 	if (strncmp(dev, "fuse", 4))
-		return;
+		goto out;
 
 	strtol(dev + 4, &ep, 10);
 	if (*ep != '\0')
-		return;
+		goto out;
 
 	do_unmount(dev, fd);
+
+out:
+	close(fd);
 }
 
 /* Check if kernel is doing init in background */