kernel/linux.git/drivers/usb/misc/appledisplay.c, branch v4.9.331

appledisplay: fix error handling in the scheduled work

2019-11-28T17:29:05+00:00

commit 91feb01596e5efc0cc922cc73f5583114dccf4d2 upstream. The work item can operate on 1. stale memory left over from the last transfer the actual length of the data transfered needs to be checked 2. memory already freed the error handling in appledisplay_probe() needs to cancel the work in that case Reported-and-tested-by: syzbot+495dab1f175edc9c2f13@syzkaller.appspotmail.com Signed-off-by: Oliver Neukum Cc: stable Link: https://lore.kernel.org/r/20191106124902.7765-1-oneukum@suse.com Signed-off-by: Greg Kroah-Hartman

USB: misc: appledisplay: fix backlight update_status return code

2019-11-28T17:28:30+00:00

[ Upstream commit 090158555ff8d194a98616034100b16697dd80d0 ] Upon success the update_status handler returns a positive number corresponding to the number of bytes transferred by usb_control_msg. However the return code of the update_status handler should indicate if an error occurred(negative) or how many bytes of the user's input to sysfs that was consumed. Return code zero indicates all bytes were consumed. The bug can for example result in the update_status handler being called twice, the second time with only the "unconsumed" part of the user's input to sysfs. Effectively setting an incorrect brightness. Change the update_status handler to return zero for all successful transactions and forward usb_control_msg's error code upon failure. Signed-off-by: Mattias Jacobsson <2pi@mok.nu> Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

usb: appledisplay: Add 27" Apple Cinema Display

2018-12-13T08:20:27+00:00

commit d7859905301880ad3e16272399d26900af3ac496 upstream. Add another Apple Cinema Display to the list of supported displays. Signed-off-by: Alexander Theissen Cc: stable Signed-off-by: Greg Kroah-Hartman

USB: misc: appledisplay: add 20" Apple Cinema Display

2018-11-27T15:09:41+00:00

commit f6501f49199097b99e4e263644d88c90d1ec1060 upstream. Add another Apple Cinema Display to the list of supported displays Signed-off-by: Mattias Jacobsson <2pi@mok.nu> Cc: stable Signed-off-by: Greg Kroah-Hartman

usb: misc: appledisplay: don't print on ENOMEM

2016-08-30T17:17:37+00:00

All kmalloc-based functions print enough information on failures. Signed-off-by: Wolfram Sang Signed-off-by: Greg Kroah-Hartman

usb: misc: appledisplay: don't print error when allocating urb fails

2016-08-15T13:54:26+00:00

kmalloc will print enough information in case of failure. Signed-off-by: Wolfram Sang Signed-off-by: Greg Kroah-Hartman

USB: appledisplay: Remove deprecated create_singlethread_workqueue

2016-08-09T13:49:01+00:00

The workqueue "wq" is involved in controlling the brightness of an Apple Cinema Display over USB. It has a single work item(&pdata->work) per appledisplay and hence doesn't require ordering. Also, it is not being used on a memory reclaim path. Hence, the singlethreaded workqueue has been replaced with the use of system_wq. System workqueues have been able to handle high level of concurrency for a long time now and hence it's not required to have a singlethreaded workqueue just to gain concurrency. Unlike a dedicated per-cpu workqueue created with create_singlethread_workqueue(), system_wq allows multiple work items to overlap executions even on the same CPU; however, a per-cpu workqueue doesn't have any CPU locality or global ordering guarantee unless the target CPU is explicitly specified and thus the increase of local concurrency shouldn't make any difference. The work item is self-requeueing and needs to wait for the in-flight work item to finish before proceeding with destruction. Hence, it has been sync cancelled in appledisplay_disconnect(). This also ensures that there are no pending tasks while disconnecting the driver. Signed-off-by: Bhaktipriya Shridhar Acked-by: Tejun Heo Signed-off-by: Greg Kroah-Hartman

USB: appledisplay: Deletion of a check before backlight_device_unregister()

2015-03-18T15:56:40+00:00

The backlight_device_unregister() function tests whether its argument is NULL and then returns immediately. Thus the test around the call is not needed. This issue was detected by using the Coccinelle software. Signed-off-by: Markus Elfring Signed-off-by: Greg Kroah-Hartman

USB: appledisplay: fix race between reading and writing from the device

2014-05-27T23:03:57+00:00

The workqueue handler may call appledisplay_bl_get_brightness() while user space calls appledisplay_bl_update_status(). As they share a buffer that must not happen. Use a mutex for mutual exclusion. Signed-off-by: Oliver Neukum Signed-off-by: Greg Kroah-Hartman

USB: appledisplay: Convert /n to \n

2014-05-27T22:00:22+00:00

Use a newline character appropriately. Signed-off-by: Joe Perches Signed-off-by: Greg Kroah-Hartman