4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: David Disseldorp <ddiss@xxxxxxx> commit d8a6e505d6bba2250852fbc1c1c86fe68aaf9af3 upstream. An open directory may have a NULL private_data pointer prior to readdir. Fixes: 0de1f4c6f6c0 ("Add way to query server fs info for smb3") Signed-off-by: David Disseldorp <ddiss@xxxxxxx> Signed-off-by: Steve French <smfrench@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/cifs/ioctl.c | 2 ++ 1 file changed, 2 insertions(+) --- a/fs/cifs/ioctl.c +++ b/fs/cifs/ioctl.c @@ -272,6 +272,8 @@ long cifs_ioctl(struct file *filep, unsi rc = -EOPNOTSUPP; break; case CIFS_IOC_GET_MNT_INFO: + if (pSMBFile == NULL) + break; tcon = tlink_tcon(pSMBFile->tlink); rc = smb_mnt_get_fsinfo(xid, tcon, (void __user *)arg); break;