lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Message-ID: <20221115100039.441295-1-pawell@cadence.com>
Date:   Tue, 15 Nov 2022 05:00:39 -0500
From:   Pawel Laszczak <pawell@...ence.com>
To:     <peter.chen@...nel.org>
CC:     <linux-usb@...r.kernel.org>, <gregkh@...uxfoundation.org>,
        <felipe.balbi@...ux.intel.com>, <rogerq@...nel.org>,
        <a-govindraju@...com>, <linux-kernel@...r.kernel.org>,
        Pawel Laszczak <pawell@...ence.com>, <stable@...r.kernel.org>
Subject: [PATCH] usb: cdns3: remove fetched trb from cache before dequeuing

After doorbell DMA fetches the TRB. If during dequeuing request
driver changes NORMAL TRB to LINK TRB but doesn't delete it from
controller cache then controller will handle cached TRB and packet
can be lost.

The example scenario for this issue looks like:
1. queue request - set doorbell
2. dequeue request
3. send OUT data packet from host
4. Device will accept this packet which is unexpected
5. queue new request - set doorbell
6. Device lost the expected packet.

By setting DFLUSH controller clears DRDY bit and stop DMA transfer.

Fixes: 7733f6c32e36 ("usb: cdns3: Add Cadence USB3 DRD Driver")
cc: <stable@...r.kernel.org>
Signed-off-by: Pawel Laszczak <pawell@...ence.com>
---
 drivers/usb/cdns3/cdns3-gadget.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/drivers/usb/cdns3/cdns3-gadget.c b/drivers/usb/cdns3/cdns3-gadget.c
index 5adcb349718c..ccfaebca6faa 100644
--- a/drivers/usb/cdns3/cdns3-gadget.c
+++ b/drivers/usb/cdns3/cdns3-gadget.c
@@ -2614,6 +2614,7 @@ int cdns3_gadget_ep_dequeue(struct usb_ep *ep,
 	u8 req_on_hw_ring = 0;
 	unsigned long flags;
 	int ret = 0;
+	int val;
 
 	if (!ep || !request || !ep->desc)
 		return -EINVAL;
@@ -2649,6 +2650,13 @@ int cdns3_gadget_ep_dequeue(struct usb_ep *ep,
 
 	/* Update ring only if removed request is on pending_req_list list */
 	if (req_on_hw_ring && link_trb) {
+		/* Stop DMA */
+		writel(EP_CMD_DFLUSH, &priv_dev->regs->ep_cmd);
+
+		/* wait for DFLUSH cleared */
+		readl_poll_timeout_atomic(&priv_dev->regs->ep_cmd, val,
+					  !(val & EP_CMD_DFLUSH), 1, 1000);
+
 		link_trb->buffer = cpu_to_le32(TRB_BUFFER(priv_ep->trb_pool_dma +
 			((priv_req->end_trb + 1) * TRB_SIZE)));
 		link_trb->control = cpu_to_le32((le32_to_cpu(link_trb->control) & TRB_CYCLE) |
@@ -2660,6 +2668,10 @@ int cdns3_gadget_ep_dequeue(struct usb_ep *ep,
 
 	cdns3_gadget_giveback(priv_ep, priv_req, -ECONNRESET);
 
+	req = cdns3_next_request(&priv_ep->pending_req_list);
+	if (req)
+		cdns3_rearm_transfer(priv_ep, 1);
+
 not_found:
 	spin_unlock_irqrestore(&priv_dev->lock, flags);
 	return ret;
-- 
2.25.1

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ