[PATCH 3.13.y-ckt 10/30] usb: cdc-acm: handle unlinked urb in acm read callback

From	Kamal Mostafa <kamal@canonical.com>
Newsgroups	linux.kernel
Subject	[PATCH 3.13.y-ckt 10/30] usb: cdc-acm: handle unlinked urb in acm read callback
Date	2016-02-10 22:50 +0100
Message-ID	<r0KO8-7Qy-53@gated-at.bofh.it> (permalink)
References	<r0KO5-7Qy-3@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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3.13.11-ckt35 -stable review patch.  If anyone has any objections, please let me know.

---8<------------------------------------------------------------

From: Lu Baolu <baolu.lu@linux.intel.com>

commit 19454462acb1bdef80542061bdc9b410e4ed1ff6 upstream.

In current acm driver, the bulk-in callback function ignores the
URBs unlinked in usb core.

This causes unexpected data loss in some cases. For example,
runtime suspend entry will unlinked all urbs and set urb->status
to -ENOENT even those urbs might have data not processed yet.
Hence, data loss occurs.

This patch lets bulk-in callback function handle unlinked urbs
to avoid data loss.

Signed-off-by: Tang Jian Qiang <jianqiang.tang@intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Acked-by: Oliver Neukum <oneukum@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ kamal: backport to 3.19-stable: context ]
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
---
 drivers/usb/class/cdc-acm.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index 87f216d..917cfdc 100644
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -399,7 +399,8 @@ static void acm_read_bulk_callback(struct urb *urb)
 	if (urb->status) {
 		dev_dbg(&acm->data->dev, "%s - non-zero urb status: %d\n",
 							__func__, urb->status);
-		return;
+		if ((urb->status != -ENOENT) || (urb->actual_length == 0))
+			return;
 	}
 	acm_process_read_urb(acm, urb);
 
-- 
1.9.1

Thread

[3.13.y-ckt stable] Linux 3.13.11-ckt35 stable review Kamal Mostafa <kamal@canonical.com> - 2016-02-10 22:50 +0100
  [PATCH 3.13.y-ckt 26/30] ALSA: dummy: Disable switching timer backend via sysfs Kamal Mostafa <kamal@canonical.com> - 2016-02-10 22:50 +0100
  [PATCH 3.13.y-ckt 30/30] powerpc/perf: Remove PPMU_HAS_SSLOT flag for Power8 Kamal Mostafa <kamal@canonical.com> - 2016-02-10 22:50 +0100
  [PATCH 3.13.y-ckt 20/30] USB: option: fix Cinterion AHxx enumeration Kamal Mostafa <kamal@canonical.com> - 2016-02-10 22:50 +0100
  [PATCH 3.13.y-ckt 27/30] drm/vmwgfx: respect 'nomodeset' Kamal Mostafa <kamal@canonical.com> - 2016-02-10 22:50 +0100
  [PATCH 3.13.y-ckt 18/30] ALSA: seq: Degrade the error message for too many opens Kamal Mostafa <kamal@canonical.com> - 2016-02-10 22:50 +0100
  [PATCH 3.13.y-ckt 10/30] usb: cdc-acm: handle unlinked urb in acm read callback Kamal Mostafa <kamal@canonical.com> - 2016-02-10 22:50 +0100
  [PATCH 3.13.y-ckt 07/30] qeth: initialize net_device with carrier off Kamal Mostafa <kamal@canonical.com> - 2016-02-10 22:50 +0100
  [PATCH 3.13.y-ckt 05/30] USB: serial: visor: fix crash on detecting device without write_urbs Kamal Mostafa <kamal@canonical.com> - 2016-02-10 22:50 +0100
  [PATCH 3.13.y-ckt 09/30] x86/irq: Call chip->irq_set_affinity in proper context Kamal Mostafa <kamal@canonical.com> - 2016-02-10 22:50 +0100
  [PATCH 3.13.y-ckt 24/30] SCSI: fix crashes in sd and sr runtime PM Kamal Mostafa <kamal@canonical.com> - 2016-02-10 22:50 +0100
  [PATCH 3.13.y-ckt 06/30] ASN.1: Fix non-match detection failure on data overrun Kamal Mostafa <kamal@canonical.com> - 2016-02-10 22:50 +0100
  [PATCH 3.13.y-ckt 22/30] ALSA: usb-audio: Fix TEAC UD-501/UD-503/NT-503 usb delay Kamal Mostafa <kamal@canonical.com> - 2016-02-10 22:50 +0100
  [PATCH 3.13.y-ckt 17/30] ALSA: seq: Fix incorrect sanity check at snd_seq_oss_synth_cleanup() Kamal Mostafa <kamal@canonical.com> - 2016-02-10 22:50 +0100
  [PATCH 3.13.y-ckt 14/30] USB: cp210x: add ID for IAI USB to RS485 adaptor Kamal Mostafa <kamal@canonical.com> - 2016-02-10 22:50 +0100
  [PATCH 3.13.y-ckt 02/30] [media] usbvision: fix leak of usb_dev on failure paths in usbvision_probe() Kamal Mostafa <kamal@canonical.com> - 2016-02-10 23:00 +0100
  [PATCH 3.13.y-ckt 08/30] iio: adis_buffer: Fix out-of-bounds memory access Kamal Mostafa <kamal@canonical.com> - 2016-02-10 23:00 +0100
  [PATCH 3.13.y-ckt 03/30] [media] usbvision: fix crash on detecting device with invalid configuration Kamal Mostafa <kamal@canonical.com> - 2016-02-10 23:00 +0100

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