Fix f_flags/f_mode in case of lookup_instantiate_filp() from open(pathname, 3)

Just set f_flags when shoving struct file into nameidata; don't
postpone that until __dentry_open().  do_filp_open() has correct
value; lookup_instantiate_filp() doesn't - we lose the difference
between O_RDWR and 3 by that point.

We still set .intent.open.flags, so no fs code needs to be changed.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 4 insertions, 2 deletions

diff --git a/fs/namei.c b/fs/namei.c
index dad4b80..d517f73 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1640,6 +1640,7 @@ struct file *do_filp_open(int dfd, const char *pathname,
 		if (filp == NULL)
 			return ERR_PTR(-ENFILE);
 		nd.intent.open.file = filp;
+		filp->f_flags = open_flag;
 		nd.intent.open.flags = flag;
 		nd.intent.open.create_mode = 0;
 		error = do_path_lookup(dfd, pathname,
@@ -1685,6 +1686,7 @@ struct file *do_filp_open(int dfd, const char *pathname,
 	if (filp == NULL)
 		goto exit_parent;
 	nd.intent.open.file = filp;
+	filp->f_flags = open_flag;
 	nd.intent.open.flags = flag;
 	nd.intent.open.create_mode = mode;
 	dir = nd.path.dentry;
@@ -1725,7 +1727,7 @@ do_last:
 			mnt_drop_write(nd.path.mnt);
 			goto exit;
 		}
-		filp = nameidata_to_filp(&nd, open_flag);
+		filp = nameidata_to_filp(&nd);
 		mnt_drop_write(nd.path.mnt);
 		if (nd.root.mnt)
 			path_put(&nd.root);
@@ -1789,7 +1791,7 @@ ok:
 			mnt_drop_write(nd.path.mnt);
 		goto exit;
 	}
-	filp = nameidata_to_filp(&nd, open_flag);
+	filp = nameidata_to_filp(&nd);
 	if (!IS_ERR(filp)) {
 		error = ima_path_check(&filp->f_path, filp->f_mode &
 			       (MAY_READ | MAY_WRITE | MAY_EXEC));