This is a note to let you know that I've just added the patch titled CIFS: fix type confusion in copy offload ioctl to the 3.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: cifs-fix-type-confusion-in-copy-offload-ioctl.patch and it can be found in the queue-3.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 4c17a6d56bb0cad3066a714e94f7185a24b40f49 Mon Sep 17 00:00:00 2001 From: Jann Horn <jann@xxxxxxxxx> Date: Fri, 11 Sep 2015 16:27:27 +0200 Subject: CIFS: fix type confusion in copy offload ioctl From: Jann Horn <jann@xxxxxxxxx> commit 4c17a6d56bb0cad3066a714e94f7185a24b40f49 upstream. This might lead to local privilege escalation (code execution as kernel) for systems where the following conditions are met: - CONFIG_CIFS_SMB2 and CONFIG_CIFS_POSIX are enabled - a cifs filesystem is mounted where: - the mount option "vers" was used and set to a value >=2.0 - the attacker has write access to at least one file on the filesystem To attack this, an attacker would have to guess the target_tcon pointer (but guessing wrong doesn't cause a crash, it just returns an error code) and win a narrow race. Signed-off-by: Jann Horn <jann@xxxxxxxxx> Signed-off-by: Steve French <smfrench@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/cifs/ioctl.c | 6 ++++++ 1 file changed, 6 insertions(+) --- a/fs/cifs/ioctl.c +++ b/fs/cifs/ioctl.c @@ -67,6 +67,12 @@ static long cifs_ioctl_clone(unsigned in goto out_drop_write; } + if (src_file.file->f_op->unlocked_ioctl != cifs_ioctl) { + rc = -EBADF; + cifs_dbg(VFS, "src file seems to be from a different filesystem type\n"); + goto out_fput; + } + if ((!src_file.file->private_data) || (!dst_file->private_data)) { rc = -EBADF; cifs_dbg(VFS, "missing cifsFileInfo on copy range src file\n"); Patches currently in stable-queue which might be from jann@xxxxxxxxx are queue-3.14/cifs-fix-type-confusion-in-copy-offload-ioctl.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html