linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	stable@vger.kernel.org, Alan Stern <stern@rowland.harvard.edu>,
	Guido Kiener <guido.kiener@rohde-schwarz.com>,
	Felipe Balbi <felipe.balbi@linux.intel.com>,
	"Sasha Levin (Microsoft)" <sashal@kernel.org>
Subject: [PATCH 4.9 11/32] usb: gadget: net2280: Fix overrun of OUT messages
Date: Thu,  2 May 2019 17:20:57 +0200	[thread overview]
Message-ID: <20190502143318.704653010@linuxfoundation.org> (raw)
In-Reply-To: <20190502143314.649935114@linuxfoundation.org>

[ Upstream commit 9d6a54c1430647355a5e23434881b2ca3d192b48 ]

The OUT endpoint normally blocks (NAK) subsequent packets when a
short packet was received and returns an incomplete queue entry to
the gadget driver. Thereby the gadget driver can detect a short packet
when reading queue entries with a length that is not equal to a
multiple of packet size.

The start_queue() function enables receiving OUT packets regardless of
the content of the OUT FIFO. This results in a race: With the current
code, it's possible that the "!ep->is_in && (readl(&ep->regs->ep_stat)
& BIT(NAK_OUT_PACKETS))" test in start_dma() will fail, then a short
packet will be received, and then start_queue() will call
stop_out_naking(). That's what we don't want (OUT naking gets turned
off while there is data in the FIFO) because then the next driver
request might receive a mixture of old and new packets.

With the patch, this race can't occur because the FIFO's state is
tested after we know that OUT naking is already turned on, and OUT
naking is stopped only when both of the conditions are met.  This
ensures that all received data is delivered to the gadget driver,
which can detect a short packet now before new packets are appended
to the last short packet.

Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Guido Kiener <guido.kiener@rohde-schwarz.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Sasha Levin (Microsoft) <sashal@kernel.org>
---
 drivers/usb/gadget/udc/net2280.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/usb/gadget/udc/net2280.c b/drivers/usb/gadget/udc/net2280.c
index 7a8c36642293..57b88f4f49c5 100644
--- a/drivers/usb/gadget/udc/net2280.c
+++ b/drivers/usb/gadget/udc/net2280.c
@@ -870,9 +870,6 @@ static void start_queue(struct net2280_ep *ep, u32 dmactl, u32 td_dma)
 	(void) readl(&ep->dev->pci->pcimstctl);
 
 	writel(BIT(DMA_START), &dma->dmastat);
-
-	if (!ep->is_in)
-		stop_out_naking(ep);
 }
 
 static void start_dma(struct net2280_ep *ep, struct net2280_request *req)
@@ -911,6 +908,7 @@ static void start_dma(struct net2280_ep *ep, struct net2280_request *req)
 			writel(BIT(DMA_START), &dma->dmastat);
 			return;
 		}
+		stop_out_naking(ep);
 	}
 
 	tmp = dmactl_default;
-- 
2.19.1




  parent reply	other threads:[~2019-05-02 15:22 UTC|newest]

Thread overview: 38+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-05-02 15:20 [PATCH 4.9 00/32] 4.9.173-stable review Greg Kroah-Hartman
2019-05-02 15:20 ` [PATCH 4.9 01/32] usbnet: ipheth: prevent TX queue timeouts when device not ready Greg Kroah-Hartman
2019-05-02 15:20 ` [PATCH 4.9 02/32] usbnet: ipheth: fix potential null pointer dereference in ipheth_carrier_set Greg Kroah-Hartman
2019-05-02 15:20 ` [PATCH 4.9 03/32] media: vivid: check if the cec_adapter is valid Greg Kroah-Hartman
2019-05-02 15:20 ` [PATCH 4.9 04/32] ARM: dts: bcm283x: Fix hdmi hpd gpio pull Greg Kroah-Hartman
2019-05-02 15:20 ` [PATCH 4.9 05/32] s390: limit brk randomization to 32MB Greg Kroah-Hartman
2019-05-02 15:20 ` [PATCH 4.9 06/32] qlcnic: Avoid potential NULL pointer dereference Greg Kroah-Hartman
2019-05-02 15:20 ` [PATCH 4.9 07/32] netfilter: nft_set_rbtree: check for inactive element after flag mismatch Greg Kroah-Hartman
2019-05-02 15:20 ` [PATCH 4.9 08/32] netfilter: bridge: set skb transport_header before entering NF_INET_PRE_ROUTING Greg Kroah-Hartman
2019-05-02 15:20 ` [PATCH 4.9 09/32] sc16is7xx: missing unregister/delete driver on error in sc16is7xx_init() Greg Kroah-Hartman
2019-05-02 15:20 ` [PATCH 4.9 10/32] serial: ar933x_uart: Fix build failure with disabled console Greg Kroah-Hartman
2019-05-02 15:20 ` Greg Kroah-Hartman [this message]
2019-05-02 15:20 ` [PATCH 4.9 12/32] usb: gadget: net2280: Fix net2280_dequeue() Greg Kroah-Hartman
2019-05-02 15:20 ` [PATCH 4.9 13/32] usb: gadget: net2272: Fix net2272_dequeue() Greg Kroah-Hartman
2019-05-02 15:21 ` [PATCH 4.9 14/32] ARM: dts: pfla02: increase phy reset duration Greg Kroah-Hartman
2019-05-02 15:21 ` [PATCH 4.9 15/32] net: ks8851: Dequeue RX packets explicitly Greg Kroah-Hartman
2019-05-02 15:21 ` [PATCH 4.9 16/32] net: ks8851: Reassert reset pin if chip ID check fails Greg Kroah-Hartman
2019-05-02 15:21 ` [PATCH 4.9 17/32] net: ks8851: Delay requesting IRQ until opened Greg Kroah-Hartman
2019-05-02 15:21 ` [PATCH 4.9 18/32] net: ks8851: Set initial carrier state to down Greg Kroah-Hartman
2019-05-02 15:21 ` [PATCH 4.9 19/32] staging: rtl8712: uninitialized memory in read_bbreg_hdl() Greg Kroah-Hartman
2019-05-02 15:21 ` [PATCH 4.9 20/32] NFS: Fix a typo in nfs_init_timeout_values() Greg Kroah-Hartman
2019-05-02 15:21 ` [PATCH 4.9 21/32] net: xilinx: fix possible object reference leak Greg Kroah-Hartman
2019-05-02 15:21 ` [PATCH 4.9 22/32] net: ibm: " Greg Kroah-Hartman
2019-05-02 15:21 ` [PATCH 4.9 23/32] net: ethernet: ti: " Greg Kroah-Hartman
2019-05-02 15:21 ` [PATCH 4.9 24/32] scsi: qla4xxx: fix a potential NULL pointer dereference Greg Kroah-Hartman
2019-05-02 15:21 ` [PATCH 4.9 25/32] usb: u132-hcd: fix resource leak Greg Kroah-Hartman
2019-05-02 15:21 ` [PATCH 4.9 26/32] ceph: fix use-after-free on symlink traversal Greg Kroah-Hartman
2019-05-02 15:21 ` [PATCH 4.9 27/32] scsi: zfcp: reduce flood of fcrscn1 trace records on multi-element RSCN Greg Kroah-Hartman
2019-05-02 15:21 ` [PATCH 4.9 28/32] libata: fix using DMA buffers on stack Greg Kroah-Hartman
2019-05-02 15:21 ` [PATCH 4.9 29/32] gpio: of: Fix of_gpiochip_add() error path Greg Kroah-Hartman
2019-05-02 15:21 ` [PATCH 4.9 30/32] kconfig/[mn]conf: handle backspace (^H) key Greg Kroah-Hartman
2019-05-02 15:21 ` [PATCH 4.9 31/32] leds: pca9532: fix a potential NULL pointer dereference Greg Kroah-Hartman
2019-05-02 15:21 ` [PATCH 4.9 32/32] vfio/type1: Limit DMA mappings per container Greg Kroah-Hartman
2019-05-02 23:06 ` [PATCH 4.9 00/32] 4.9.173-stable review kernelci.org bot
2019-05-03  7:04 ` Naresh Kamboju
2019-05-03  9:27 ` Jon Hunter
2019-05-03 17:15 ` Guenter Roeck
2019-05-03 21:21 ` shuah

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20190502143318.704653010@linuxfoundation.org \
    --to=gregkh@linuxfoundation.org \
    --cc=felipe.balbi@linux.intel.com \
    --cc=guido.kiener@rohde-schwarz.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=sashal@kernel.org \
    --cc=stable@vger.kernel.org \
    --cc=stern@rowland.harvard.edu \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).