autofs: fix missing fput for FSCONFIG_SET_FD

[ Upstream commit 6a64c52 ]

If you pass an fd using FSCONFIG_SET_FD, autofs_parse_fd() "steals" the
param->file and so the fs_context infrastructure will not do fput() for
us.

Fixes: e6ec453 ("autofs: convert autofs to use the new mount api")
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
Link: https://lore.kernel.org/r/20240731-fsconfig-fsparam_fd-fixes-v2-1-e7c472224417@cyphar.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

Author: cyphar

fs/autofs/inode.c

@@ -172,8 +172,7 @@ static int autofs_parse_fd(struct fs_context *fc, struct autofs_sb_info *sbi,
 	ret = autofs_check_pipe(pipe);
 	if (ret < 0) {
 		errorf(fc, "Invalid/unusable pipe");
-		if (param->type != fs_value_is_file)
-			fput(pipe);
+		fput(pipe);
 		return -EBADF;
 	}