linux-media.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
* [PATCH v2 0/5] media: uvcvideo: Fix race conditions
@ 2020-09-08 19:45 Guenter Roeck
  2020-09-08 19:45 ` [PATCH v2 1/5] media: uvcvideo: Cancel async worker earlier Guenter Roeck
                   ` (4 more replies)
  0 siblings, 5 replies; 8+ messages in thread
From: Guenter Roeck @ 2020-09-08 19:45 UTC (permalink / raw)
  To: Laurent Pinchart
  Cc: Mauro Carvalho Chehab, Sakari Ailus, linux-uvc-devel, linux-usb,
	linux-media, linux-kernel

The uvcvideo code has no lock protection against USB disconnects
while video operations are ongoing. This has resulted in random
error reports, typically pointing to a crash in usb_ifnum_to_if(),
called from usb_hcd_alloc_bandwidth(). A typical traceback is as
follows.

usb 1-4: USB disconnect, device number 3
BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
PGD 0 P4D 0
Oops: 0000 [#1] PREEMPT SMP PTI
CPU: 0 PID: 5633 Comm: V4L2CaptureThre Not tainted 4.19.113-08536-g5d29ca36db06 #1
Hardware name: GOOGLE Edgar, BIOS Google_Edgar.7287.167.156 03/25/2019
RIP: 0010:usb_ifnum_to_if+0x29/0x40
Code: <...>
RSP: 0018:ffffa46f42a47a80 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff904a396c9000
RDX: ffff904a39641320 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffa46f42a47a80 R08: 0000000000000002 R09: 0000000000000000
R10: 0000000000009975 R11: 0000000000000009 R12: 0000000000000000
R13: ffff904a396b3800 R14: ffff904a39e88000 R15: 0000000000000000
FS: 00007f396448e700(0000) GS:ffff904a3ba00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000016cb46000 CR4: 00000000001006f0
Call Trace:
 usb_hcd_alloc_bandwidth+0x1ee/0x30f
 usb_set_interface+0x1a3/0x2b7
 uvc_video_start_transfer+0x29b/0x4b8 [uvcvideo]
 uvc_video_start_streaming+0x91/0xdd [uvcvideo]
 uvc_start_streaming+0x28/0x5d [uvcvideo]
 vb2_start_streaming+0x61/0x143 [videobuf2_common]
 vb2_core_streamon+0xf7/0x10f [videobuf2_common]
 uvc_queue_streamon+0x2e/0x41 [uvcvideo]
 uvc_ioctl_streamon+0x42/0x5c [uvcvideo]
 __video_do_ioctl+0x33d/0x42a
 video_usercopy+0x34e/0x5ff
 ? video_ioctl2+0x16/0x16
 v4l2_ioctl+0x46/0x53
 do_vfs_ioctl+0x50a/0x76f
 ksys_ioctl+0x58/0x83
 __x64_sys_ioctl+0x1a/0x1e
 do_syscall_64+0x54/0xde

While there are not many references to this problem on mailing lists, it is
reported on a regular basis on various Chromebooks (roughly 300 reports
per month). The problem is relatively easy to reproduce by adding msleep()
calls into the code.

I tried to reproduce the problem with non-uvcvideo webcams, but was
unsuccessful. I was unable to get Philips (pwc) webcams to work. gspca
based webcams don't experience the problem, or at least I was unable to
reproduce it (The gspa driver does not trigger sending USB messages in the
open function, and otherwise uses the locking mechanism provided by the
v4l2/vb2 core).

I don't presume to claim that I found every issue, but this patch series
should fix at least the major problems.

The patch series was tested exensively on a Chromebook running chromeos-4.19
and on a Linux system running a v5.8.y based kernel.

v2:
- Added details about problem frequency and testing with non-uvc webcams
  to summary
- In patch 4/5, return EPOLLERR instead of -ENODEV on poll errors
- Fix description in patch 5/5

----------------------------------------------------------------
Guenter Roeck (5):
      media: uvcvideo: Cancel async worker earlier
      media: uvcvideo: Lock video streams and queues while unregistering
      media: uvcvideo: Release stream queue when unregistering video device
      media: uvcvideo: Protect uvc queue file operations against disconnect
      media: uvcvideo: Abort uvc_v4l2_open if video device is unregistered

 drivers/media/usb/uvc/uvc_ctrl.c   | 11 ++++++----
 drivers/media/usb/uvc/uvc_driver.c | 12 ++++++++++
 drivers/media/usb/uvc/uvc_queue.c  | 32 +++++++++++++++++++++++++--
 drivers/media/usb/uvc/uvc_v4l2.c   | 45 ++++++++++++++++++++++++++++++++++++--
 drivers/media/usb/uvc/uvcvideo.h   |  1 +
 5 files changed, 93 insertions(+), 8 deletions(-)

^ permalink raw reply	[flat|nested] 8+ messages in thread
* [PATCH v2 1/5] media: uvcvideo: Cancel async worker earlier
  2020-09-08 19:45 [PATCH v2 0/5] media: uvcvideo: Fix race conditions Guenter Roeck
@ 2020-09-08 19:45 ` Guenter Roeck
  2020-09-08 19:45 ` [PATCH v2 2/5] media: uvcvideo: Lock video streams and queues while unregistering Guenter Roeck
                   ` (3 subsequent siblings)
  4 siblings, 0 replies; 8+ messages in thread
From: Guenter Roeck @ 2020-09-08 19:45 UTC (permalink / raw)
  To: Laurent Pinchart
  Cc: Mauro Carvalho Chehab, Sakari Ailus, linux-uvc-devel, linux-usb,
	linux-media, linux-kernel, Guenter Roeck, Alan Stern,
	Hans Verkuil

So far the asynchronous control worker was canceled only in
uvc_ctrl_cleanup_device. This is much later than the call to
uvc_disconnect. However, after the call to uvc_disconnect returns,
there must be no more USB activity. This can result in all kinds
of problems in the USB code. One observed example:

URB ffff993e83d0bc00 submitted while active
WARNING: CPU: 0 PID: 4046 at drivers/usb/core/urb.c:364 usb_submit_urb+0x4ba/0x55e
Modules linked in: <...>
CPU: 0 PID: 4046 Comm: kworker/0:35 Not tainted 4.19.139 #18
Hardware name: Google Phaser/Phaser, BIOS Google_Phaser.10952.0.0 08/09/2018
Workqueue: events uvc_ctrl_status_event_work [uvcvideo]
RIP: 0010:usb_submit_urb+0x4ba/0x55e
Code: <...>
RSP: 0018:ffffb08d471ebde8 EFLAGS: 00010246
RAX: a6da85d923ea5d00 RBX: ffff993e71985928 RCX: 0000000000000000
RDX: ffff993f37a1de90 RSI: ffff993f37a153d0 RDI: ffff993f37a153d0
RBP: ffffb08d471ebe28 R08: 000000000000003b R09: 001424bf85822e96
R10: 0000001000000000 R11: ffffffff975a4398 R12: ffff993e83d0b000
R13: ffff993e83d0bc00 R14: 0000000000000000 R15: 00000000fffffff0
FS:  0000000000000000(0000) GS:ffff993f37a00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000ec9c0000 CR3: 000000025b160000 CR4: 0000000000340ef0
Call Trace:
 uvc_ctrl_status_event_work+0xd6/0x107 [uvcvideo]
 process_one_work+0x19b/0x4c5
 worker_thread+0x10d/0x286
 kthread+0x138/0x140
 ? process_one_work+0x4c5/0x4c5
 ? kthread_associate_blkcg+0xc1/0xc1
 ret_from_fork+0x1f/0x40

Introduce new function uvc_ctrl_stop_device() to cancel the worker
and call it from uvc_unregister_video() to solve the problem.

Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
v2: No change

 drivers/media/usb/uvc/uvc_ctrl.c   | 11 +++++++----
 drivers/media/usb/uvc/uvc_driver.c |  1 +
 drivers/media/usb/uvc/uvcvideo.h   |  1 +
 3 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c
index e399b9fad757..130c56e0063d 100644
--- a/drivers/media/usb/uvc/uvc_ctrl.c
+++ b/drivers/media/usb/uvc/uvc_ctrl.c
@@ -2340,14 +2340,17 @@ static void uvc_ctrl_cleanup_mappings(struct uvc_device *dev,
 	}
 }
 
-void uvc_ctrl_cleanup_device(struct uvc_device *dev)
+void uvc_ctrl_stop_device(struct uvc_device *dev)
 {
-	struct uvc_entity *entity;
-	unsigned int i;
-
 	/* Can be uninitialized if we are aborting on probe error. */
 	if (dev->async_ctrl.work.func)
 		cancel_work_sync(&dev->async_ctrl.work);
+}
+
+void uvc_ctrl_cleanup_device(struct uvc_device *dev)
+{
+	struct uvc_entity *entity;
+	unsigned int i;
 
 	/* Free controls and control mappings for all entities. */
 	list_for_each_entry(entity, &dev->entities, list) {
diff --git a/drivers/media/usb/uvc/uvc_driver.c b/drivers/media/usb/uvc/uvc_driver.c
index 431d86e1c94b..bfba67a69185 100644
--- a/drivers/media/usb/uvc/uvc_driver.c
+++ b/drivers/media/usb/uvc/uvc_driver.c
@@ -1952,6 +1952,7 @@ static void uvc_unregister_video(struct uvc_device *dev)
 	}
 
 	uvc_status_unregister(dev);
+	uvc_ctrl_stop_device(dev);
 
 	if (dev->vdev.dev)
 		v4l2_device_unregister(&dev->vdev);
diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
index 6ab972c643e3..543afcd9fd26 100644
--- a/drivers/media/usb/uvc/uvcvideo.h
+++ b/drivers/media/usb/uvc/uvcvideo.h
@@ -830,6 +830,7 @@ int uvc_query_v4l2_menu(struct uvc_video_chain *chain,
 int uvc_ctrl_add_mapping(struct uvc_video_chain *chain,
 			 const struct uvc_control_mapping *mapping);
 int uvc_ctrl_init_device(struct uvc_device *dev);
+void uvc_ctrl_stop_device(struct uvc_device *dev);
 void uvc_ctrl_cleanup_device(struct uvc_device *dev);
 int uvc_ctrl_restore_values(struct uvc_device *dev);
 bool uvc_ctrl_status_event(struct urb *urb, struct uvc_video_chain *chain,
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 8+ messages in thread
* [PATCH v2 2/5] media: uvcvideo: Lock video streams and queues while unregistering
  2020-09-08 19:45 [PATCH v2 0/5] media: uvcvideo: Fix race conditions Guenter Roeck
  2020-09-08 19:45 ` [PATCH v2 1/5] media: uvcvideo: Cancel async worker earlier Guenter Roeck
@ 2020-09-08 19:45 ` Guenter Roeck
  2020-09-08 19:45 ` [PATCH v2 3/5] media: uvcvideo: Release stream queue when unregistering video device Guenter Roeck
                   ` (2 subsequent siblings)
  4 siblings, 0 replies; 8+ messages in thread
From: Guenter Roeck @ 2020-09-08 19:45 UTC (permalink / raw)
  To: Laurent Pinchart
  Cc: Mauro Carvalho Chehab, Sakari Ailus, linux-uvc-devel, linux-usb,
	linux-media, linux-kernel, Guenter Roeck, Alan Stern,
	Hans Verkuil

The call to uvc_disconnect() is not protected by any mutex.
This means it can and will be called while other accesses to the video
device are in progress. This can cause all kinds of race conditions,
including crashes such as the following.

usb 1-4: USB disconnect, device number 3
BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
PGD 0 P4D 0
Oops: 0000 [#1] PREEMPT SMP PTI
CPU: 0 PID: 5633 Comm: V4L2CaptureThre Not tainted 4.19.113-08536-g5d29ca36db06 #1
Hardware name: GOOGLE Edgar, BIOS Google_Edgar.7287.167.156 03/25/2019
RIP: 0010:usb_ifnum_to_if+0x29/0x40
Code: <...>
RSP: 0018:ffffa46f42a47a80 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff904a396c9000
RDX: ffff904a39641320 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffa46f42a47a80 R08: 0000000000000002 R09: 0000000000000000
R10: 0000000000009975 R11: 0000000000000009 R12: 0000000000000000
R13: ffff904a396b3800 R14: ffff904a39e88000 R15: 0000000000000000
FS: 00007f396448e700(0000) GS:ffff904a3ba00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000016cb46000 CR4: 00000000001006f0
Call Trace:
 usb_hcd_alloc_bandwidth+0x1ee/0x30f
 usb_set_interface+0x1a3/0x2b7
 uvc_video_start_transfer+0x29b/0x4b8 [uvcvideo]
 uvc_video_start_streaming+0x91/0xdd [uvcvideo]
 uvc_start_streaming+0x28/0x5d [uvcvideo]
 vb2_start_streaming+0x61/0x143 [videobuf2_common]
 vb2_core_streamon+0xf7/0x10f [videobuf2_common]
 uvc_queue_streamon+0x2e/0x41 [uvcvideo]
 uvc_ioctl_streamon+0x42/0x5c [uvcvideo]
 __video_do_ioctl+0x33d/0x42a
 video_usercopy+0x34e/0x5ff
 ? video_ioctl2+0x16/0x16
 v4l2_ioctl+0x46/0x53
 do_vfs_ioctl+0x50a/0x76f
 ksys_ioctl+0x58/0x83
 __x64_sys_ioctl+0x1a/0x1e
 do_syscall_64+0x54/0xde

usb_set_interface() should not be called after the USB device has been
unregistered. However, in the above case the disconnect happened after
v4l2_ioctl() was called, but before the call to usb_ifnum_to_if().

Acquire various mutexes in uvc_unregister_video() to fix the majority
(maybe all) of the observed race conditions.

The uvc_device lock prevents races against suspend and resume calls
and the poll function.

The uvc_streaming lock prevents races against stream related functions;
for the most part, those are ioctls. This lock also requires other
functions using this lock to check if a video device is still registered
after acquiring it. For example, it was observed that the video device
was already unregistered by the time the stream lock was acquired in
uvc_ioctl_streamon().

The uvc_queue lock prevents races against queue functions, Most of
those are already protected by the uvc_streaming lock, but some
are called directly. This is done as added protection; an actual race
was not (yet) observed.

Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
v2: No change

 drivers/media/usb/uvc/uvc_driver.c |  9 +++++++
 drivers/media/usb/uvc/uvc_v4l2.c   | 39 +++++++++++++++++++++++++++++-
 2 files changed, 47 insertions(+), 1 deletion(-)

diff --git a/drivers/media/usb/uvc/uvc_driver.c b/drivers/media/usb/uvc/uvc_driver.c
index bfba67a69185..a5808305f1e3 100644
--- a/drivers/media/usb/uvc/uvc_driver.c
+++ b/drivers/media/usb/uvc/uvc_driver.c
@@ -1941,14 +1941,22 @@ static void uvc_unregister_video(struct uvc_device *dev)
 {
 	struct uvc_streaming *stream;
 
+	mutex_lock(&dev->lock);
+
 	list_for_each_entry(stream, &dev->streams, list) {
 		if (!video_is_registered(&stream->vdev))
 			continue;
 
+		mutex_lock(&stream->mutex);
+		mutex_lock(&stream->queue.mutex);
+
 		video_unregister_device(&stream->vdev);
 		video_unregister_device(&stream->meta.vdev);
 
 		uvc_debugfs_cleanup_stream(stream);
+
+		mutex_unlock(&stream->queue.mutex);
+		mutex_unlock(&stream->mutex);
 	}
 
 	uvc_status_unregister(dev);
@@ -1960,6 +1968,7 @@ static void uvc_unregister_video(struct uvc_device *dev)
 	if (media_devnode_is_registered(dev->mdev.devnode))
 		media_device_unregister(&dev->mdev);
 #endif
+	mutex_unlock(&dev->lock);
 }
 
 int uvc_register_video_device(struct uvc_device *dev,
diff --git a/drivers/media/usb/uvc/uvc_v4l2.c b/drivers/media/usb/uvc/uvc_v4l2.c
index 0335e69b70ab..7e5e583dae5e 100644
--- a/drivers/media/usb/uvc/uvc_v4l2.c
+++ b/drivers/media/usb/uvc/uvc_v4l2.c
@@ -237,6 +237,12 @@ static int uvc_v4l2_try_format(struct uvc_streaming *stream,
 	 * the Windows driver).
 	 */
 	mutex_lock(&stream->mutex);
+	if (!video_is_registered(&stream->vdev)) {
+		mutex_unlock(&stream->mutex);
+		ret = -ENODEV;
+		goto done;
+	}
+
 	if (stream->dev->quirks & UVC_QUIRK_PROBE_EXTRAFIELDS)
 		probe->dwMaxVideoFrameSize =
 			stream->ctrl.dwMaxVideoFrameSize;
@@ -274,6 +280,12 @@ static int uvc_v4l2_get_format(struct uvc_streaming *stream,
 		return -EINVAL;
 
 	mutex_lock(&stream->mutex);
+
+	if (!video_is_registered(&stream->vdev)) {
+		ret = -ENODEV;
+		goto done;
+	}
+
 	format = stream->cur_format;
 	frame = stream->cur_frame;
 
@@ -312,6 +324,11 @@ static int uvc_v4l2_set_format(struct uvc_streaming *stream,
 
 	mutex_lock(&stream->mutex);
 
+	if (!video_is_registered(&stream->vdev)) {
+		ret = -ENODEV;
+		goto done;
+	}
+
 	if (uvc_queue_allocated(&stream->queue)) {
 		ret = -EBUSY;
 		goto done;
@@ -387,6 +404,11 @@ static int uvc_v4l2_set_streamparm(struct uvc_streaming *stream,
 
 	mutex_lock(&stream->mutex);
 
+	if (!video_is_registered(&stream->vdev)) {
+		mutex_unlock(&stream->mutex);
+		return -ENODEV;
+	}
+
 	if (uvc_queue_streaming(&stream->queue)) {
 		mutex_unlock(&stream->mutex);
 		return -EBUSY;
@@ -713,6 +735,10 @@ static int uvc_ioctl_reqbufs(struct file *file, void *fh,
 		return ret;
 
 	mutex_lock(&stream->mutex);
+	if (!video_is_registered(&stream->vdev)) {
+		mutex_unlock(&stream->mutex);
+		return -ENODEV;
+	}
 	ret = uvc_request_buffers(&stream->queue, rb);
 	mutex_unlock(&stream->mutex);
 	if (ret < 0)
@@ -797,7 +823,12 @@ static int uvc_ioctl_streamon(struct file *file, void *fh,
 		return -EBUSY;
 
 	mutex_lock(&stream->mutex);
+	if (!video_is_registered(&stream->vdev)) {
+		ret = -ENODEV;
+		goto unlock;
+	}
 	ret = uvc_queue_streamon(&stream->queue, type);
+unlock:
 	mutex_unlock(&stream->mutex);
 
 	return ret;
@@ -808,15 +839,21 @@ static int uvc_ioctl_streamoff(struct file *file, void *fh,
 {
 	struct uvc_fh *handle = fh;
 	struct uvc_streaming *stream = handle->stream;
+	int ret = 0;
 
 	if (!uvc_has_privileges(handle))
 		return -EBUSY;
 
 	mutex_lock(&stream->mutex);
+	if (!video_is_registered(&stream->vdev)) {
+		ret = -ENODEV;
+		goto unlock;
+	}
 	uvc_queue_streamoff(&stream->queue, type);
+unlock:
 	mutex_unlock(&stream->mutex);
 
-	return 0;
+	return ret;
 }
 
 static int uvc_ioctl_enum_input(struct file *file, void *fh,
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 8+ messages in thread
* [PATCH v2 3/5] media: uvcvideo: Release stream queue when unregistering video device
  2020-09-08 19:45 [PATCH v2 0/5] media: uvcvideo: Fix race conditions Guenter Roeck
  2020-09-08 19:45 ` [PATCH v2 1/5] media: uvcvideo: Cancel async worker earlier Guenter Roeck
  2020-09-08 19:45 ` [PATCH v2 2/5] media: uvcvideo: Lock video streams and queues while unregistering Guenter Roeck
@ 2020-09-08 19:45 ` Guenter Roeck
  2020-09-08 19:45 ` [PATCH v2 4/5] media: uvcvideo: Protect uvc queue file operations against disconnect Guenter Roeck
  2020-09-08 19:45 ` [PATCH v2 5/5] media: uvcvideo: Abort uvc_v4l2_open if video device is unregistered Guenter Roeck
  4 siblings, 0 replies; 8+ messages in thread
From: Guenter Roeck @ 2020-09-08 19:45 UTC (permalink / raw)
  To: Laurent Pinchart
  Cc: Mauro Carvalho Chehab, Sakari Ailus, linux-uvc-devel, linux-usb,
	linux-media, linux-kernel, Guenter Roeck, Alan Stern,
	Hans Verkuil

The following traceback was observed when stress testing the uvcvideo
driver.

config->interface[0] is NULL
WARNING: CPU: 0 PID: 2757 at drivers/usb/core/usb.c:285 usb_ifnum_to_if+0x81/0x85
^^^ added log message and WARN() to prevent crash
Modules linked in: <...>
CPU: 0 PID: 2757 Comm: inotify_reader Not tainted 4.19.139 #20
Hardware name: Google Phaser/Phaser, BIOS Google_Phaser.10952.0.0 08/09/2018
RIP: 0010:usb_ifnum_to_if+0x81/0x85
Code: <...>
RSP: 0018:ffff9ee20141fa58 EFLAGS: 00010246
RAX: 438a0e5a525f1800 RBX: 0000000000000000 RCX: 0000000000000000
RDX: ffff975477a1de90 RSI: ffff975477a153d0 RDI: ffff975477a153d0
RBP: ffff9ee20141fa70 R08: 000000000000002c R09: 002daec189138d78
R10: 0000001000000000 R11: ffffffffa7da42e6 R12: ffff975459594800
R13: 0000000000000001 R14: 0000000000000001 R15: ffff975465376400
FS:  00007ddebffd6700(0000) GS:ffff975477a00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000012c83000 CR3: 00000001bbaf8000 CR4: 0000000000340ef0
Call Trace:
 usb_set_interface+0x3b/0x2f3
 uvc_video_stop_streaming+0x38/0x81 [uvcvideo]
 uvc_stop_streaming+0x21/0x49 [uvcvideo]
 __vb2_queue_cancel+0x33/0x249 [videobuf2_common]
 vb2_core_queue_release+0x1c/0x45 [videobuf2_common]
 uvc_queue_release+0x26/0x32 [uvcvideo]
 uvc_v4l2_release+0x41/0xdd [uvcvideo]
 v4l2_release+0x99/0xed
 __fput+0xf0/0x1ea
 task_work_run+0x7f/0xa7
 do_exit+0x1d1/0x6eb
 do_group_exit+0x9d/0xac
 get_signal+0x135/0x482
 do_signal+0x4a/0x63c
 exit_to_usermode_loop+0x86/0xa5
 do_syscall_64+0x171/0x269
 ? __do_page_fault+0x272/0x474
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7ddec156dc26
Code: Bad RIP value.
RSP: 002b:00007ddebffd5c10 EFLAGS: 00000293 ORIG_RAX: 0000000000000017
RAX: fffffffffffffdfe RBX: 000000000000000a RCX: 00007ddec156dc26
RDX: 0000000000000000 RSI: 00007ddebffd5d28 RDI: 000000000000000a
RBP: 00007ddebffd5c50 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 00007ddebffd5d28
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000

When this was observed, a USB disconnect was in progress, uvc_disconnect()
had returned, but usb_disable_device() was still running.
Drivers are not supposed to call any USB functions after the driver
disconnect function has been called. The uvcvideo driver does not follow
that convention and tries to write to the disconnected USB interface
anyway. This results in a variety of race conditions.

To solve this specific problem, release the uvc queue from
uvc_unregister_video() after the associated video devices have been
unregistered. Since the function already holds the uvc queue mutex,
bypass uvc_queue_release() and call vb2_queue_release() directly.

Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
v2: No change

 drivers/media/usb/uvc/uvc_driver.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/media/usb/uvc/uvc_driver.c b/drivers/media/usb/uvc/uvc_driver.c
index a5808305f1e3..27b72806b9b9 100644
--- a/drivers/media/usb/uvc/uvc_driver.c
+++ b/drivers/media/usb/uvc/uvc_driver.c
@@ -1955,6 +1955,8 @@ static void uvc_unregister_video(struct uvc_device *dev)
 
 		uvc_debugfs_cleanup_stream(stream);
 
+		vb2_queue_release(&stream->queue.queue);
+
 		mutex_unlock(&stream->queue.mutex);
 		mutex_unlock(&stream->mutex);
 	}
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 8+ messages in thread
* [PATCH v2 4/5] media: uvcvideo: Protect uvc queue file operations against disconnect
  2020-09-08 19:45 [PATCH v2 0/5] media: uvcvideo: Fix race conditions Guenter Roeck
                   ` (2 preceding siblings ...)
  2020-09-08 19:45 ` [PATCH v2 3/5] media: uvcvideo: Release stream queue when unregistering video device Guenter Roeck
@ 2020-09-08 19:45 ` Guenter Roeck
  2020-09-08 19:45 ` [PATCH v2 5/5] media: uvcvideo: Abort uvc_v4l2_open if video device is unregistered Guenter Roeck
  4 siblings, 0 replies; 8+ messages in thread
From: Guenter Roeck @ 2020-09-08 19:45 UTC (permalink / raw)
  To: Laurent Pinchart
  Cc: Mauro Carvalho Chehab, Sakari Ailus, linux-uvc-devel, linux-usb,
	linux-media, linux-kernel, Guenter Roeck, Alan Stern,
	Hans Verkuil

uvc queue file operations have no mutex protection against USB
disconnect. This is questionable at least for the poll operation,
which has to wait for the uvc queue mutex. By the time that mutex
has been acquired, is it possible that the video device has been
unregistered.

Protect all file operations by using the queue mutex to avoid
possible race conditions. After acquiring the mutex, check if
the video device is still registered, and bail out if not.

Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
v2: Return EPOLLERR instead of -ENODEV on poll errors

 drivers/media/usb/uvc/uvc_queue.c | 32 +++++++++++++++++++++++++++++--
 1 file changed, 30 insertions(+), 2 deletions(-)

diff --git a/drivers/media/usb/uvc/uvc_queue.c b/drivers/media/usb/uvc/uvc_queue.c
index cd60c6c1749e..b2c59ce38008 100644
--- a/drivers/media/usb/uvc/uvc_queue.c
+++ b/drivers/media/usb/uvc/uvc_queue.c
@@ -358,24 +358,52 @@ int uvc_queue_streamoff(struct uvc_video_queue *queue, enum v4l2_buf_type type)
 
 int uvc_queue_mmap(struct uvc_video_queue *queue, struct vm_area_struct *vma)
 {
-	return vb2_mmap(&queue->queue, vma);
+	struct uvc_streaming *stream = uvc_queue_to_stream(queue);
+	int ret;
+
+	mutex_lock(&queue->mutex);
+	if (!video_is_registered(&stream->vdev)) {
+		ret = -ENODEV;
+		goto unlock;
+	}
+	ret = vb2_mmap(&queue->queue, vma);
+unlock:
+	mutex_unlock(&queue->mutex);
+	return ret;
 }
 
 #ifndef CONFIG_MMU
 unsigned long uvc_queue_get_unmapped_area(struct uvc_video_queue *queue,
 		unsigned long pgoff)
 {
-	return vb2_get_unmapped_area(&queue->queue, 0, 0, pgoff, 0);
+	struct uvc_streaming *stream = uvc_queue_to_stream(queue);
+	unsigned long ret;
+
+	mutex_lock(&queue->mutex);
+	if (!video_is_registered(&stream->vdev)) {
+		ret = -ENODEV;
+		goto unlock;
+	}
+	ret = vb2_get_unmapped_area(&queue->queue, 0, 0, pgoff, 0);
+unlock:
+	mutex_unlock(&queue->mutex);
+	return ret;
 }
 #endif
 
 __poll_t uvc_queue_poll(struct uvc_video_queue *queue, struct file *file,
 			    poll_table *wait)
 {
+	struct uvc_streaming *stream = uvc_queue_to_stream(queue);
 	__poll_t ret;
 
 	mutex_lock(&queue->mutex);
+	if (!video_is_registered(&stream->vdev)) {
+		ret = EPOLLERR;
+		goto unlock;
+	}
 	ret = vb2_poll(&queue->queue, file, wait);
+unlock:
 	mutex_unlock(&queue->mutex);
 
 	return ret;
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 8+ messages in thread
* [PATCH v2 5/5] media: uvcvideo: Abort uvc_v4l2_open if video device is unregistered
  2020-09-08 19:45 [PATCH v2 0/5] media: uvcvideo: Fix race conditions Guenter Roeck
                   ` (3 preceding siblings ...)
  2020-09-08 19:45 ` [PATCH v2 4/5] media: uvcvideo: Protect uvc queue file operations against disconnect Guenter Roeck
@ 2020-09-08 19:45 ` Guenter Roeck
  2020-09-09 12:19   ` [kbuild] " Dan Carpenter
  4 siblings, 1 reply; 8+ messages in thread
From: Guenter Roeck @ 2020-09-08 19:45 UTC (permalink / raw)
  To: Laurent Pinchart
  Cc: Mauro Carvalho Chehab, Sakari Ailus, linux-uvc-devel, linux-usb,
	linux-media, linux-kernel, Guenter Roeck, Alan Stern,
	Hans Verkuil

uvc_v4l2_open() acquires the uvc device mutex. After doing so,
it does not check if the video device is still registered. This may
result in race conditions and can result in an attempt to submit an urb
to a disconnected USB interface (from uvc_status_start).

The problem was observed after adding a call to msleep() just before
acquiring the mutex and disconnecting the camera during the sleep.

Check if the video device is still registered after acquiring the mutex
to avoid the problem. In the release function, only call uvc_status_stop()
if the video device is still registered. If the video device has been
unregistered, the urb associated with uvc status has already been killed
in uvc_status_unregister(). Trying to kill it again won't do any good
and might have unexpected side effects.

Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
v2: Fix typo in description. The USB message is sent from uvc_status_start()
    in the open function, not from uvc_v4l2_open().

 drivers/media/usb/uvc/uvc_v4l2.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/media/usb/uvc/uvc_v4l2.c b/drivers/media/usb/uvc/uvc_v4l2.c
index 7e5e583dae5e..1f7d454557b9 100644
--- a/drivers/media/usb/uvc/uvc_v4l2.c
+++ b/drivers/media/usb/uvc/uvc_v4l2.c
@@ -548,6 +548,10 @@ static int uvc_v4l2_open(struct file *file)
 	}
 
 	mutex_lock(&stream->dev->lock);
+	if (!video_is_registered(&stream->vdev)) {
+		mutex_unlock(&stream->dev->lock);
+		return -ENODEV;
+	}
 	if (stream->dev->users == 0) {
 		ret = uvc_status_start(stream->dev, GFP_KERNEL);
 		if (ret < 0) {
@@ -590,7 +594,7 @@ static int uvc_v4l2_release(struct file *file)
 	file->private_data = NULL;
 
 	mutex_lock(&stream->dev->lock);
-	if (--stream->dev->users == 0)
+	if (--stream->dev->users == 0 && video_is_registered(&stream->vdev))
 		uvc_status_stop(stream->dev);
 	mutex_unlock(&stream->dev->lock);
 
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 8+ messages in thread
* [kbuild] Re: [PATCH v2 5/5] media: uvcvideo: Abort uvc_v4l2_open if video device is unregistered
  2020-09-08 19:45 ` [PATCH v2 5/5] media: uvcvideo: Abort uvc_v4l2_open if video device is unregistered Guenter Roeck
@ 2020-09-09 12:19   ` Dan Carpenter
  2020-09-09 15:13     ` Guenter Roeck
  0 siblings, 1 reply; 8+ messages in thread
From: Dan Carpenter @ 2020-09-09 12:19 UTC (permalink / raw)
  To: kbuild, Guenter Roeck, Laurent Pinchart
  Cc: lkp, kbuild-all, Mauro Carvalho Chehab, linux-media,
	Sakari Ailus, linux-uvc-devel, linux-usb, linux-kernel,
	Guenter Roeck, Alan Stern, Hans Verkuil

[-- Attachment #1: Type: text/plain, Size: 6279 bytes --]

Hi Guenter,

url:    https://github.com/0day-ci/linux/commits/Guenter-Roeck/media-uvcvideo-Fix-race-conditions/20200909-121927 
base:   git://linuxtv.org/media_tree.git master
config: x86_64-randconfig-m001-20200909 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-15) 9.3.0

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>

smatch warnings:
drivers/media/usb/uvc/uvc_v4l2.c:553 uvc_v4l2_open() warn: possible memory leak of 'handle'

# https://github.com/0day-ci/linux/commit/50911975ff9b21d08ff5408e496683b8ac567b1c 
git remote add linux-review https://github.com/0day-ci/linux 
git fetch --no-tags linux-review Guenter-Roeck/media-uvcvideo-Fix-race-conditions/20200909-121927
git checkout 50911975ff9b21d08ff5408e496683b8ac567b1c
vim +/handle +553 drivers/media/usb/uvc/uvc_v4l2.c

bec43661b1dc00 drivers/media/video/uvc/uvc_v4l2.c Hans Verkuil     2008-12-30  530  static int uvc_v4l2_open(struct file *file)
c0efd232929c2c drivers/media/video/uvc/uvc_v4l2.c Laurent Pinchart 2008-06-30  531  {
35f02a681b72ec drivers/media/video/uvc/uvc_v4l2.c Laurent Pinchart 2009-06-28  532  	struct uvc_streaming *stream;
c0efd232929c2c drivers/media/video/uvc/uvc_v4l2.c Laurent Pinchart 2008-06-30  533  	struct uvc_fh *handle;
c0efd232929c2c drivers/media/video/uvc/uvc_v4l2.c Laurent Pinchart 2008-06-30  534  	int ret = 0;
c0efd232929c2c drivers/media/video/uvc/uvc_v4l2.c Laurent Pinchart 2008-06-30  535  
c0efd232929c2c drivers/media/video/uvc/uvc_v4l2.c Laurent Pinchart 2008-06-30  536  	uvc_trace(UVC_TRACE_CALLS, "uvc_v4l2_open\n");
35f02a681b72ec drivers/media/video/uvc/uvc_v4l2.c Laurent Pinchart 2009-06-28  537  	stream = video_drvdata(file);
c0efd232929c2c drivers/media/video/uvc/uvc_v4l2.c Laurent Pinchart 2008-06-30  538  
35f02a681b72ec drivers/media/video/uvc/uvc_v4l2.c Laurent Pinchart 2009-06-28  539  	ret = usb_autopm_get_interface(stream->dev->intf);
c0efd232929c2c drivers/media/video/uvc/uvc_v4l2.c Laurent Pinchart 2008-06-30  540  	if (ret < 0)
716fdee110ceb8 drivers/media/video/uvc/uvc_v4l2.c Laurent Pinchart 2009-09-29  541  		return ret;
c0efd232929c2c drivers/media/video/uvc/uvc_v4l2.c Laurent Pinchart 2008-06-30  542  
c0efd232929c2c drivers/media/video/uvc/uvc_v4l2.c Laurent Pinchart 2008-06-30  543  	/* Create the device handle. */
f14d4988c28e52 drivers/media/usb/uvc/uvc_v4l2.c   Laurent Pinchart 2018-01-16  544  	handle = kzalloc(sizeof(*handle), GFP_KERNEL);
                                                                                        ^^^^^^^^^^^^^^^^

c0efd232929c2c drivers/media/video/uvc/uvc_v4l2.c Laurent Pinchart 2008-06-30  545  	if (handle == NULL) {
35f02a681b72ec drivers/media/video/uvc/uvc_v4l2.c Laurent Pinchart 2009-06-28  546  		usb_autopm_put_interface(stream->dev->intf);
716fdee110ceb8 drivers/media/video/uvc/uvc_v4l2.c Laurent Pinchart 2009-09-29  547  		return -ENOMEM;
c0efd232929c2c drivers/media/video/uvc/uvc_v4l2.c Laurent Pinchart 2008-06-30  548  	}
c0efd232929c2c drivers/media/video/uvc/uvc_v4l2.c Laurent Pinchart 2008-06-30  549  
17706f5653a90f drivers/media/usb/uvc/uvc_v4l2.c   Laurent Pinchart 2013-04-25  550  	mutex_lock(&stream->dev->lock);
50911975ff9b21 drivers/media/usb/uvc/uvc_v4l2.c   Guenter Roeck    2020-09-08  551  	if (!video_is_registered(&stream->vdev)) {
50911975ff9b21 drivers/media/usb/uvc/uvc_v4l2.c   Guenter Roeck    2020-09-08  552  		mutex_unlock(&stream->dev->lock);
50911975ff9b21 drivers/media/usb/uvc/uvc_v4l2.c   Guenter Roeck    2020-09-08 @553  		return -ENODEV;
                                                                                                ^^^^^^^^^^^^^^
kfree(handle);

50911975ff9b21 drivers/media/usb/uvc/uvc_v4l2.c   Guenter Roeck    2020-09-08  554  	}
17706f5653a90f drivers/media/usb/uvc/uvc_v4l2.c   Laurent Pinchart 2013-04-25  555  	if (stream->dev->users == 0) {
17706f5653a90f drivers/media/usb/uvc/uvc_v4l2.c   Laurent Pinchart 2013-04-25  556  		ret = uvc_status_start(stream->dev, GFP_KERNEL);
35f02a681b72ec drivers/media/video/uvc/uvc_v4l2.c Laurent Pinchart 2009-06-28  557  		if (ret < 0) {
17706f5653a90f drivers/media/usb/uvc/uvc_v4l2.c   Laurent Pinchart 2013-04-25  558  			mutex_unlock(&stream->dev->lock);
a82a45f65377b0 drivers/media/usb/uvc/uvc_v4l2.c   Oliver Neukum    2013-01-10  559  			usb_autopm_put_interface(stream->dev->intf);
04a37e0f32f988 drivers/media/video/uvc/uvc_v4l2.c Laurent Pinchart 2009-05-19  560  			kfree(handle);
716fdee110ceb8 drivers/media/video/uvc/uvc_v4l2.c Laurent Pinchart 2009-09-29  561  			return ret;
04a37e0f32f988 drivers/media/video/uvc/uvc_v4l2.c Laurent Pinchart 2009-05-19  562  		}
04a37e0f32f988 drivers/media/video/uvc/uvc_v4l2.c Laurent Pinchart 2009-05-19  563  	}
04a37e0f32f988 drivers/media/video/uvc/uvc_v4l2.c Laurent Pinchart 2009-05-19  564  
17706f5653a90f drivers/media/usb/uvc/uvc_v4l2.c   Laurent Pinchart 2013-04-25  565  	stream->dev->users++;
17706f5653a90f drivers/media/usb/uvc/uvc_v4l2.c   Laurent Pinchart 2013-04-25  566  	mutex_unlock(&stream->dev->lock);
17706f5653a90f drivers/media/usb/uvc/uvc_v4l2.c   Laurent Pinchart 2013-04-25  567  
d8da7513bcf983 drivers/media/usb/uvc/uvc_v4l2.c   Hans Verkuil     2015-03-09  568  	v4l2_fh_init(&handle->vfh, &stream->vdev);
b4012002f3a398 drivers/media/video/uvc/uvc_v4l2.c Hans de Goede    2012-04-08  569  	v4l2_fh_add(&handle->vfh);
8e113595edf074 drivers/media/video/uvc/uvc_v4l2.c Laurent Pinchart 2009-07-01  570  	handle->chain = stream->chain;
35f02a681b72ec drivers/media/video/uvc/uvc_v4l2.c Laurent Pinchart 2009-06-28  571  	handle->stream = stream;
c0efd232929c2c drivers/media/video/uvc/uvc_v4l2.c Laurent Pinchart 2008-06-30  572  	handle->state = UVC_HANDLE_PASSIVE;
c0efd232929c2c drivers/media/video/uvc/uvc_v4l2.c Laurent Pinchart 2008-06-30  573  	file->private_data = handle;
c0efd232929c2c drivers/media/video/uvc/uvc_v4l2.c Laurent Pinchart 2008-06-30  574  
716fdee110ceb8 drivers/media/video/uvc/uvc_v4l2.c Laurent Pinchart 2009-09-29  575  	return 0;
c0efd232929c2c drivers/media/video/uvc/uvc_v4l2.c Laurent Pinchart 2008-06-30  576  }

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org 

[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 49876 bytes --]

[-- Attachment #3: Type: text/plain, Size: 149 bytes --]

_______________________________________________
kbuild mailing list -- kbuild@lists.01.org
To unsubscribe send an email to kbuild-leave@lists.01.org

^ permalink raw reply	[flat|nested] 8+ messages in thread
* Re: [kbuild] Re: [PATCH v2 5/5] media: uvcvideo: Abort uvc_v4l2_open if video device is unregistered
  2020-09-09 12:19   ` [kbuild] " Dan Carpenter
@ 2020-09-09 15:13     ` Guenter Roeck
  0 siblings, 0 replies; 8+ messages in thread
From: Guenter Roeck @ 2020-09-09 15:13 UTC (permalink / raw)
  To: Dan Carpenter, kbuild, Laurent Pinchart
  Cc: lkp, kbuild-all, Mauro Carvalho Chehab, linux-media,
	Sakari Ailus, linux-uvc-devel, linux-usb, linux-kernel,
	Alan Stern, Hans Verkuil

On 9/9/20 5:19 AM, Dan Carpenter wrote:
> Hi Guenter,
> 
> url:    https://github.com/0day-ci/linux/commits/Guenter-Roeck/media-uvcvideo-Fix-race-conditions/20200909-121927 
> base:   git://linuxtv.org/media_tree.git master
> config: x86_64-randconfig-m001-20200909 (attached as .config)
> compiler: gcc-9 (Debian 9.3.0-15) 9.3.0
> 
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <lkp@intel.com>
> Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
> 
> smatch warnings:
> drivers/media/usb/uvc/uvc_v4l2.c:553 uvc_v4l2_open() warn: possible memory leak of 'handle'
> 

Good catch. It is also missing a call to usb_autopm_put_interface().
I'll fix that in v3.

Thanks,
Guenter

> # https://github.com/0day-ci/linux/commit/50911975ff9b21d08ff5408e496683b8ac567b1c 
> git remote add linux-review https://github.com/0day-ci/linux 
> git fetch --no-tags linux-review Guenter-Roeck/media-uvcvideo-Fix-race-conditions/20200909-121927
> git checkout 50911975ff9b21d08ff5408e496683b8ac567b1c
> vim +/handle +553 drivers/media/usb/uvc/uvc_v4l2.c
> 
> bec43661b1dc00 drivers/media/video/uvc/uvc_v4l2.c Hans Verkuil     2008-12-30  530  static int uvc_v4l2_open(struct file *file)
> c0efd232929c2c drivers/media/video/uvc/uvc_v4l2.c Laurent Pinchart 2008-06-30  531  {
> 35f02a681b72ec drivers/media/video/uvc/uvc_v4l2.c Laurent Pinchart 2009-06-28  532  	struct uvc_streaming *stream;
> c0efd232929c2c drivers/media/video/uvc/uvc_v4l2.c Laurent Pinchart 2008-06-30  533  	struct uvc_fh *handle;
> c0efd232929c2c drivers/media/video/uvc/uvc_v4l2.c Laurent Pinchart 2008-06-30  534  	int ret = 0;
> c0efd232929c2c drivers/media/video/uvc/uvc_v4l2.c Laurent Pinchart 2008-06-30  535  
> c0efd232929c2c drivers/media/video/uvc/uvc_v4l2.c Laurent Pinchart 2008-06-30  536  	uvc_trace(UVC_TRACE_CALLS, "uvc_v4l2_open\n");
> 35f02a681b72ec drivers/media/video/uvc/uvc_v4l2.c Laurent Pinchart 2009-06-28  537  	stream = video_drvdata(file);
> c0efd232929c2c drivers/media/video/uvc/uvc_v4l2.c Laurent Pinchart 2008-06-30  538  
> 35f02a681b72ec drivers/media/video/uvc/uvc_v4l2.c Laurent Pinchart 2009-06-28  539  	ret = usb_autopm_get_interface(stream->dev->intf);
> c0efd232929c2c drivers/media/video/uvc/uvc_v4l2.c Laurent Pinchart 2008-06-30  540  	if (ret < 0)
> 716fdee110ceb8 drivers/media/video/uvc/uvc_v4l2.c Laurent Pinchart 2009-09-29  541  		return ret;
> c0efd232929c2c drivers/media/video/uvc/uvc_v4l2.c Laurent Pinchart 2008-06-30  542  
> c0efd232929c2c drivers/media/video/uvc/uvc_v4l2.c Laurent Pinchart 2008-06-30  543  	/* Create the device handle. */
> f14d4988c28e52 drivers/media/usb/uvc/uvc_v4l2.c   Laurent Pinchart 2018-01-16  544  	handle = kzalloc(sizeof(*handle), GFP_KERNEL);
>                                                                                         ^^^^^^^^^^^^^^^^
> 
> c0efd232929c2c drivers/media/video/uvc/uvc_v4l2.c Laurent Pinchart 2008-06-30  545  	if (handle == NULL) {
> 35f02a681b72ec drivers/media/video/uvc/uvc_v4l2.c Laurent Pinchart 2009-06-28  546  		usb_autopm_put_interface(stream->dev->intf);
> 716fdee110ceb8 drivers/media/video/uvc/uvc_v4l2.c Laurent Pinchart 2009-09-29  547  		return -ENOMEM;
> c0efd232929c2c drivers/media/video/uvc/uvc_v4l2.c Laurent Pinchart 2008-06-30  548  	}
> c0efd232929c2c drivers/media/video/uvc/uvc_v4l2.c Laurent Pinchart 2008-06-30  549  
> 17706f5653a90f drivers/media/usb/uvc/uvc_v4l2.c   Laurent Pinchart 2013-04-25  550  	mutex_lock(&stream->dev->lock);
> 50911975ff9b21 drivers/media/usb/uvc/uvc_v4l2.c   Guenter Roeck    2020-09-08  551  	if (!video_is_registered(&stream->vdev)) {
> 50911975ff9b21 drivers/media/usb/uvc/uvc_v4l2.c   Guenter Roeck    2020-09-08  552  		mutex_unlock(&stream->dev->lock);
> 50911975ff9b21 drivers/media/usb/uvc/uvc_v4l2.c   Guenter Roeck    2020-09-08 @553  		return -ENODEV;
>                                                                                                 ^^^^^^^^^^^^^^
> kfree(handle);
> 
> 50911975ff9b21 drivers/media/usb/uvc/uvc_v4l2.c   Guenter Roeck    2020-09-08  554  	}
> 17706f5653a90f drivers/media/usb/uvc/uvc_v4l2.c   Laurent Pinchart 2013-04-25  555  	if (stream->dev->users == 0) {
> 17706f5653a90f drivers/media/usb/uvc/uvc_v4l2.c   Laurent Pinchart 2013-04-25  556  		ret = uvc_status_start(stream->dev, GFP_KERNEL);
> 35f02a681b72ec drivers/media/video/uvc/uvc_v4l2.c Laurent Pinchart 2009-06-28  557  		if (ret < 0) {
> 17706f5653a90f drivers/media/usb/uvc/uvc_v4l2.c   Laurent Pinchart 2013-04-25  558  			mutex_unlock(&stream->dev->lock);
> a82a45f65377b0 drivers/media/usb/uvc/uvc_v4l2.c   Oliver Neukum    2013-01-10  559  			usb_autopm_put_interface(stream->dev->intf);
> 04a37e0f32f988 drivers/media/video/uvc/uvc_v4l2.c Laurent Pinchart 2009-05-19  560  			kfree(handle);
> 716fdee110ceb8 drivers/media/video/uvc/uvc_v4l2.c Laurent Pinchart 2009-09-29  561  			return ret;
> 04a37e0f32f988 drivers/media/video/uvc/uvc_v4l2.c Laurent Pinchart 2009-05-19  562  		}
> 04a37e0f32f988 drivers/media/video/uvc/uvc_v4l2.c Laurent Pinchart 2009-05-19  563  	}
> 04a37e0f32f988 drivers/media/video/uvc/uvc_v4l2.c Laurent Pinchart 2009-05-19  564  
> 17706f5653a90f drivers/media/usb/uvc/uvc_v4l2.c   Laurent Pinchart 2013-04-25  565  	stream->dev->users++;
> 17706f5653a90f drivers/media/usb/uvc/uvc_v4l2.c   Laurent Pinchart 2013-04-25  566  	mutex_unlock(&stream->dev->lock);
> 17706f5653a90f drivers/media/usb/uvc/uvc_v4l2.c   Laurent Pinchart 2013-04-25  567  
> d8da7513bcf983 drivers/media/usb/uvc/uvc_v4l2.c   Hans Verkuil     2015-03-09  568  	v4l2_fh_init(&handle->vfh, &stream->vdev);
> b4012002f3a398 drivers/media/video/uvc/uvc_v4l2.c Hans de Goede    2012-04-08  569  	v4l2_fh_add(&handle->vfh);
> 8e113595edf074 drivers/media/video/uvc/uvc_v4l2.c Laurent Pinchart 2009-07-01  570  	handle->chain = stream->chain;
> 35f02a681b72ec drivers/media/video/uvc/uvc_v4l2.c Laurent Pinchart 2009-06-28  571  	handle->stream = stream;
> c0efd232929c2c drivers/media/video/uvc/uvc_v4l2.c Laurent Pinchart 2008-06-30  572  	handle->state = UVC_HANDLE_PASSIVE;
> c0efd232929c2c drivers/media/video/uvc/uvc_v4l2.c Laurent Pinchart 2008-06-30  573  	file->private_data = handle;
> c0efd232929c2c drivers/media/video/uvc/uvc_v4l2.c Laurent Pinchart 2008-06-30  574  
> 716fdee110ceb8 drivers/media/video/uvc/uvc_v4l2.c Laurent Pinchart 2009-09-29  575  	return 0;
> c0efd232929c2c drivers/media/video/uvc/uvc_v4l2.c Laurent Pinchart 2008-06-30  576  }
> 
> ---
> 0-DAY CI Kernel Test Service, Intel Corporation
> https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org 
> 
> 
> _______________________________________________
> kbuild mailing list -- kbuild@lists.01.org
> To unsubscribe send an email to kbuild-leave@lists.01.org
> 


^ permalink raw reply	[flat|nested] 8+ messages in thread
end of thread, other threads:[~2020-09-09 17:20 UTC | newest]

Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-09-08 19:45 [PATCH v2 0/5] media: uvcvideo: Fix race conditions Guenter Roeck
2020-09-08 19:45 ` [PATCH v2 1/5] media: uvcvideo: Cancel async worker earlier Guenter Roeck
2020-09-08 19:45 ` [PATCH v2 2/5] media: uvcvideo: Lock video streams and queues while unregistering Guenter Roeck
2020-09-08 19:45 ` [PATCH v2 3/5] media: uvcvideo: Release stream queue when unregistering video device Guenter Roeck
2020-09-08 19:45 ` [PATCH v2 4/5] media: uvcvideo: Protect uvc queue file operations against disconnect Guenter Roeck
2020-09-08 19:45 ` [PATCH v2 5/5] media: uvcvideo: Abort uvc_v4l2_open if video device is unregistered Guenter Roeck
2020-09-09 12:19   ` [kbuild] " Dan Carpenter
2020-09-09 15:13     ` Guenter Roeck

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).