From patchwork Mon Dec 4 10:45:34 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mathias Nyman X-Patchwork-Id: 750344 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="JrNPHN/e" Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.7]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 95AEDB9 for ; Mon, 4 Dec 2023 02:44:53 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1701686694; x=1733222694; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=w0DnSPmZj85cgbMbS+eDufLxzKMrnYRs0INaeLDar+8=; b=JrNPHN/ebOGheBlRx46VxmE45b91GnECWk56rGp1BOd9Kk3Lhkl1idtS hvqekUePij93pXMy1Jh6LQ1D68R5KQO2CFcj6JpOPqBJaLmsjiMv+3hay CKax2SwlZX2ZWOt2Ya3lxfFWIBid4BJkY4vkQ5dzKPico9GzoZgTHR5KY vCdyKixowaMSu7sm+9VSEuotOS75QeBQj4x2Rs8k5vLSYGXZbjl/xqJok vfO+JICx2UxmNenEi5jaaxkerIhES5ptvK7JbBKLXVyO4qkJYOfkeDXSi 8Lj2pzUeoK8k0WpSEglqMQHsaLifleUy6eejtxdiIlKsAJZFoAV8xUpjf A==; X-IronPort-AV: E=McAfee;i="6600,9927,10913"; a="15260690" X-IronPort-AV: E=Sophos;i="6.04,249,1695711600"; d="scan'208";a="15260690" Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by fmvoesa101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 Dec 2023 02:44:54 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10913"; a="861339019" X-IronPort-AV: E=Sophos;i="6.04,249,1695711600"; d="scan'208";a="861339019" Received: from mattu-haswell.fi.intel.com ([10.237.72.199]) by FMSMGA003.fm.intel.com with ESMTP; 04 Dec 2023 02:44:51 -0800 From: Mathias Nyman To: Cc: , Mathias Nyman , Kuen-Han Tsai Subject: [PATCH v2 18/18] xhci: fix possible null pointer deref during xhci urb enqueue Date: Mon, 4 Dec 2023 12:45:34 +0200 Message-Id: <20231204104534.1335903-19-mathias.nyman@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20231204104534.1335903-1-mathias.nyman@linux.intel.com> References: <20231204104534.1335903-1-mathias.nyman@linux.intel.com> Precedence: bulk X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 There is a short gap between urb being submitted and actually added to the endpoint queue (linked). If the device is disconnected during this time then usb core is not yet aware of the pending urb, and device may be freed just before xhci_urq_enqueue() continues, dereferencing the freed device. Freeing the device is protected by the xhci spinlock, so make sure we take and keep the lock while checking that device exists, dereference it, and add the urb to the queue. Remove the unnecessary URB check, usb core checks it before calling xhci_urb_enqueue() Suggested-by: Kuen-Han Tsai Signed-off-by: Mathias Nyman --- drivers/usb/host/xhci.c | 40 +++++++++++++++++++++++----------------- 1 file changed, 23 insertions(+), 17 deletions(-) diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c index df31d44498d6..4929c4396e9e 100644 --- a/drivers/usb/host/xhci.c +++ b/drivers/usb/host/xhci.c @@ -1521,24 +1521,7 @@ static int xhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb, gfp_t mem_flag struct urb_priv *urb_priv; int num_tds; - if (!urb) - return -EINVAL; - ret = xhci_check_args(hcd, urb->dev, urb->ep, - true, true, __func__); - if (ret <= 0) - return ret ? ret : -EINVAL; - - slot_id = urb->dev->slot_id; ep_index = xhci_get_endpoint_index(&urb->ep->desc); - ep_state = &xhci->devs[slot_id]->eps[ep_index].ep_state; - - if (!HCD_HW_ACCESSIBLE(hcd)) - return -ESHUTDOWN; - - if (xhci->devs[slot_id]->flags & VDEV_PORT_ERROR) { - xhci_dbg(xhci, "Can't queue urb, port error, link inactive\n"); - return -ENODEV; - } if (usb_endpoint_xfer_isoc(&urb->ep->desc)) num_tds = urb->number_of_packets; @@ -1562,12 +1545,35 @@ static int xhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb, gfp_t mem_flag spin_lock_irqsave(&xhci->lock, flags); + ret = xhci_check_args(hcd, urb->dev, urb->ep, + true, true, __func__); + if (ret <= 0) { + ret = ret ? ret : -EINVAL; + goto free_priv; + } + + slot_id = urb->dev->slot_id; + + if (!HCD_HW_ACCESSIBLE(hcd)) { + ret = -ESHUTDOWN; + goto free_priv; + } + + if (xhci->devs[slot_id]->flags & VDEV_PORT_ERROR) { + xhci_dbg(xhci, "Can't queue urb, port error, link inactive\n"); + ret = -ENODEV; + goto free_priv; + } + if (xhci->xhc_state & XHCI_STATE_DYING) { xhci_dbg(xhci, "Ep 0x%x: URB %p submitted for non-responsive xHCI host.\n", urb->ep->desc.bEndpointAddress, urb); ret = -ESHUTDOWN; goto free_priv; } + + ep_state = &xhci->devs[slot_id]->eps[ep_index].ep_state; + if (*ep_state & (EP_GETTING_STREAMS | EP_GETTING_NO_STREAMS)) { xhci_warn(xhci, "WARN: Can't enqueue URB, ep in streams transition state %x\n", *ep_state);