From: Zhang Xiaoxu <zhangxiaoxu5@xxxxxxxxxx> commit b1763d265af62800ec96eeb79803c4c537dcef3a upstream. Commit c7803b05f74b ("smb3: fix ksmbd bigendian bug in oplock break, and move its struct to smbfs_common") use the defination of 'struct validate_negotiate_info_req' in smbfs_common, the array length of 'Dialects' changed from 1 to 4, but the protocol does not require the client to send all 4. This lead the request which satisfied with protocol and server to fail. So just ensure the request payload has the 'DialectCount' in smb2_ioctl(), then fsctl_validate_negotiate_info() will use it to validate the payload length and each dialect. Also when the {in, out}_buf_len is less than the required, should goto out to initialize the status in the response header. Fixes: f7db8fd03a4b ("ksmbd: add validation in smb2_ioctl") Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@xxxxxxxxxx> Acked-by: Namjae Jeon <linkinjeon@xxxxxxxxxx> Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/ksmbd/smb2pdu.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) --- a/fs/ksmbd/smb2pdu.c +++ b/fs/ksmbd/smb2pdu.c @@ -7637,11 +7637,16 @@ int smb2_ioctl(struct ksmbd_work *work) goto out; } - if (in_buf_len < sizeof(struct validate_negotiate_info_req)) - return -EINVAL; + if (in_buf_len < offsetof(struct validate_negotiate_info_req, + Dialects)) { + ret = -EINVAL; + goto out; + } - if (out_buf_len < sizeof(struct validate_negotiate_info_rsp)) - return -EINVAL; + if (out_buf_len < sizeof(struct validate_negotiate_info_rsp)) { + ret = -EINVAL; + goto out; + } ret = fsctl_validate_negotiate_info(conn, (struct validate_negotiate_info_req *)&req->Buffer[0],