69829f749a
commit 6becdb601bae2a043d7fb9762c4d48699528ea6e upstream. syzbot is reporting NULL pointer dereference at fuse_ctl_remove_conn() [1]. Since fc->ctl_ndents is incremented by fuse_ctl_add_conn() when new_inode() failed, fuse_ctl_remove_conn() reaches an inode-less dentry and tries to clear d_inode(dentry)->i_private field. Fix by only adding the dentry to the array after being fully set up. When tearing down the control directory, do d_invalidate() on it to get rid of any mounts that might have been added. [1] https://syzkaller.appspot.com/bug?id=f396d863067238959c91c0b7cfc10b163638cac6 Reported-by: syzbot <syzbot+32c236387d66c4516827@syzkaller.appspotmail.com> Fixes: bafa96541b25 ("[PATCH] fuse: add control filesystem") Cc: <stable@vger.kernel.org> # v2.6.18 Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.