[PATCH 3/3] virtiofsd: Check file type in lo_flush()

[Vivek Goyal <vgoyal@redhat.com>]

Currently lo_flush() is written in such a way that it expects to receive
a FLUSH requests on a regular file (and not directories). For example,
we call lo_fi_fd() which searches lo->fd_map. If we open directories
using opendir(), we keep don't keep track of these in lo->fd_map instead
we keep them in lo->dir_map. So we expect lo_flush() to be called on
regular files only.

Even linux fuse client calls FLUSH only for regular files and not
directories. So put a check for filetype and return EBADF if
lo_flush() is called on a non-regular file.

Reported-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
---
 tools/virtiofsd/passthrough_ll.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/virtiofsd/passthrough_ll.c b/tools/virtiofsd/passthrough_ll.c
index 8ba79f503a..48a109d3f6 100644
--- a/tools/virtiofsd/passthrough_ll.c
+++ b/tools/virtiofsd/passthrough_ll.c
@@ -1968,7 +1968,7 @@ static void lo_flush(fuse_req_t req, fuse_ino_t ino, struct fuse_file_info *fi)
     struct lo_data *lo = lo_data(req);
 
     inode = lo_inode(req, ino);
-    if (!inode) {
+    if (!inode || !S_ISREG(inode->filetype)) {
         fuse_reply_err(req, EBADF);
         return;
     }
-- 
2.25.4