kernel/drivers/usb/gadget/function/f_hid.c, branch 0x221E-v0.0.1-v6.19

usb: gadget: f_hid: move list and spinlock inits from bind to alloc

2026-04-11T12:29:57Z

commit 4e0a88254ad59f6c53a34bf5fa241884ec09e8b2 upstream. There was an issue when you did the following: - setup and bind an hid gadget - open /dev/hidg0 - use the resulting fd in EPOLL_CTL_ADD - unbind the UDC - bind the UDC - use the fd in EPOLL_CTL_DEL When CONFIG_DEBUG_LIST was enabled, a list_del corruption was reported within remove_wait_queue (via ep_remove_wait_queue). After some debugging I found out that the queues, which f_hid registers via poll_wait were the problem. These were initialized using init_waitqueue_head inside hidg_bind. So effectively, the bind function re-initialized the queues while there were still items in them. The solution is to move the initialization from hidg_bind to hidg_alloc to extend their lifetimes to the lifetime of the function instance. Additionally, I found many other possibly problematic init calls in the bind function, which I moved as well. Signed-off-by: Michael Zimmermann Cc: stable Link: https://patch.msgid.link/20260331184844.2388761-1-sigmaepsilon92@gmail.com Signed-off-by: Greg Kroah-Hartman

usb: gadget: f_hid: fix SuperSpeed descriptors

2026-03-19T15:15:05Z

commit 7f58b4148ef5d8ee0fb7d8113dcc38ff5374babc upstream. When adding dynamic configuration for bInterval, the value was removed from the static SuperSpeed endpoint descriptors but was not set from the configured value in hidg_bind(). Thus at SuperSpeed the interrupt endpoints have bInterval as zero which is not valid per the USB specification. Add the missing setting for SuperSpeed endpoints. Fixes: ea34925f5b2ee ("usb: gadget: hid: allow dynamic interval configuration via configfs") Cc: stable Signed-off-by: John Keeping Acked-by: Peter Korsgaard Link: https://patch.msgid.link/20260227111540.431521-1-jkeeping@inmusicbrands.com Signed-off-by: Greg Kroah-Hartman

USB: add WQ_PERCPU to alloc_workqueue users

2025-11-21T14:17:36Z

Currently if a user enqueues a work item using schedule_delayed_work() the used wq is "system_wq" (per-cpu wq) while queue_delayed_work() use WORK_CPU_UNBOUND (used when a cpu is not specified). The same applies to schedule_work() that is using system_wq and queue_work(), that makes use again of WORK_CPU_UNBOUND. This lack of consistency cannot be addressed without refactoring the API. alloc_workqueue() treats all queues as per-CPU by default, while unbound workqueues must opt-in via WQ_UNBOUND. This default is suboptimal: most workloads benefit from unbound queues, allowing the scheduler to place worker threads where they’re needed and reducing noise when CPUs are isolated. This continues the effort to refactor workqueue APIs, which began with the introduction of new workqueues and a new alloc_workqueue flag in: commit 128ea9f6ccfb ("workqueue: Add system_percpu_wq and system_dfl_wq") commit 930c2ea566af ("workqueue: Add new WQ_PERCPU flag") This change adds a new WQ_PERCPU flag to explicitly request alloc_workqueue() to be per-cpu when WQ_UNBOUND has not been specified. With the introduction of the WQ_PERCPU flag (equivalent to !WQ_UNBOUND), any alloc_workqueue() caller that doesn’t explicitly specify WQ_UNBOUND must now use WQ_PERCPU. Once migration is complete, WQ_UNBOUND can be removed and unbound will become the implicit default. Suggested-by: Tejun Heo Signed-off-by: Marco Crivellari Link: https://patch.msgid.link/20251107153737.301413-2-marco.crivellari@suse.com Signed-off-by: Greg Kroah-Hartman

usb: gadget: f_hid: Fix zero length packet transfer

2025-09-06T13:22:44Z

Set the hid req->zero flag of ep0/in_ep to true by default, then the UDC drivers can transfer a zero length packet at the end if the hid transfer with size divisible to EPs max packet size according to the USB 2.0 spec. Signed-off-by: William Wu Link: https://lore.kernel.org/r/1756204087-26111-1-git-send-email-william.wu@rock-chips.com Signed-off-by: Greg Kroah-Hartman

USB: gadget: f_hid: Fix memory leak in hidg_bind error path

2025-07-07T09:03:33Z

In hidg_bind(), if alloc_workqueue() fails after usb_assign_descriptors() has successfully allocated the USB descriptors, the current error handling does not call usb_free_all_descriptors() to free the allocated descriptors, resulting in a memory leak. Restructure the error handling by adding proper cleanup labels: - fail_free_all: cleans up workqueue and descriptors - fail_free_descs: cleans up descriptors only - fail: original cleanup for earlier failures This ensures that allocated resources are properly freed in reverse order of their allocation, preventing the memory leak when alloc_workqueue() fails. Fixes: a139c98f760ef ("USB: gadget: f_hid: Add GET_REPORT via userspace IOCTL") Cc: stable@vger.kernel.org Signed-off-by: Yuhao Jiang Link: https://lore.kernel.org/r/20250623094844.244977-1-danisjiang@gmail.com Signed-off-by: Greg Kroah-Hartman

Merge tag 'usb-6.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb

2025-06-06T19:45:35Z

Pull USB / Thunderbolt updates from Greg KH: "Here is the big set of USB and Thunderbolt changes for 6.16-rc1. Included in here are the following: - USB offload support for audio devices. I think this takes the record for the most number of patch series (30+) over the longest period of time (2+ years) to get merged properly. Many props go to Wesley Cheng for seeing this effort through, they took a major out-of-tree hacked-up-monstrosity that was created by multiple vendors for their specific devices, got it all merged into a semi-coherent set of changes, and got all of the different major subsystems to agree on how this should be implemented both with changes to their code as well as userspace apis, AND wrangled the hardware companies into agreeing to go forward with this, despite making them all redo work they had already done in their private device trees. This feature offers major power savings on embedded devices where a USB audio stream can continue to flow while the rest of the system is sleeping, something that devices running on battery power really care about. There are still some more small tweaks left to be done here, and those patches are still out for review and arguing among the different hardware companies, but this is a major step forward and a great example of how to do upstream development well. - small number of thunderbolt fixes and updates, things seem to be slowing down here (famous last words...) - xhci refactors and reworking to try to handle some rough corner cases in some hardware implementations where things don't always work properly - typec driver updates - USB3 power management reworking and updates - Removal of some old and orphaned UDC gadget drivers that had not been used in a very long time, dropping over 11 thousand lines from the tree, always a nice thing, making up for the 12k lines added for the USB offload feature. - lots of little updates and fixes in different drivers All of these have been in linux-next for over 2 weeks, the USB offload logic has been in there for 8 weeks now, with no reported issues" * tag 'usb-6.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (172 commits) ALSA: usb-audio: qcom: fix USB_XHCI dependency ASoC: qdsp6: fix compile-testing without CONFIG_OF usb: misc: onboard_usb_dev: fix build warning for CONFIG_USB_ONBOARD_DEV_USB5744=n usb: typec: tipd: fix typo in TPS_STATUS_HIGH_VOLAGE_WARNING macro USB: typec: fix const issue in typec_match() USB: gadget: udc: fix const issue in gadget_match_driver() USB: gadget: fix up const issue with struct usb_function_instance USB: serial: pl2303: add new chip PL2303GC-Q20 and PL2303GT-2AB USB: serial: bus: fix const issue in usb_serial_device_match() usb: usbtmc: Fix timeout value in get_stb usb: usbtmc: Fix read_stb function and get_stb ioctl ALSA: qc_audio_offload: try to reduce address space confusion ALSA: qc_audio_offload: avoid leaking xfer_buf allocation ALSA: qc_audio_offload: rename dma/iova/va/cpu/phys variables ALSA: usb-audio: qcom: Fix an error handling path in qc_usb_audio_probe() usb: misc: onboard_usb_dev: Fix usb5744 initialization sequence dt-bindings: usb: ti,usb8041: Add binding for TI USB8044 hub controller usb: misc: onboard_usb_dev: Add support for TI TUSB8044 hub usb: gadget: lpc32xx_udc: Use USB API functions rather than constants usb: gadget: epautoconf: Use USB API functions rather than constants ...

usb: gadget: hid: allow dynamic interval configuration via configfs

2025-05-01T15:30:48Z

This patch enhances the HID gadget driver to support dynamic configuration of the interrupt polling interval (bInterval) via configfs. A new ‘interval’ attribute is exposed under each HID function’s configfs directory, and any write to it will adjust the poll rate for all endpoints without requiring a rebuild. When the attribute has never been written, legacy defaults are preserved: • Full-Speed (FS) endpoints (IN & OUT) poll every 10 ms • High-Speed (HS) endpoints (IN & OUT) poll every 4 micro-frames (~1 ms) To implement this cleanly: • Add two new fields to f_hid_opts and f_hidg: – unsigned char interval – bool interval_user_set • Introduce dedicated f_hid_opts_interval_show/store functions. The store routine parses into an unsigned int, bounds‐checks, assigns to opts->interval, and sets opts->interval_user_set = true. • Initialize opts->interval = 4 and opts->interval_user_set = false in hidg_alloc_inst(), then copy both into the live f_hidg instance in hidg_alloc(). • In hidg_bind(), set each endpoint’s bInterval based on whether the user has written the attribute: – If interval_user_set == false, use FS=10 / HS=4 – If interval_user_set == true, use the user’s value for both FS & HS Signed-off-by: Ben Hoff Link: https://lore.kernel.org/r/20250429182809.811786-1-hoff.benjamin.k@gmail.com Signed-off-by: Greg Kroah-Hartman

HID: usbhid: Eliminate recurrent out-of-bounds bug in usbhid_parse()

2025-04-24T09:31:25Z

Update struct hid_descriptor to better reflect the mandatory and optional parts of the HID Descriptor as per USB HID 1.11 specification. Note: the kernel currently does not parse any optional HID class descriptors, only the mandatory report descriptor. Update all references to member element desc[0] to rpt_desc. Add test to verify bLength and bNumDescriptors values are valid. Replace the for loop with direct access to the mandatory HID class descriptor member for the report descriptor. This eliminates the possibility of getting an out-of-bounds fault. Add a warning message if the HID descriptor contains any unsupported optional HID class descriptors. Reported-by: syzbot+c52569baf0c843f35495@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=c52569baf0c843f35495 Fixes: f043bfc98c19 ("HID: usbhid: fix out-of-bounds bug") Cc: stable@vger.kernel.org Signed-off-by: Terry Junge Reviewed-by: Michael Kelley Signed-off-by: Jiri Kosina

usb: gadget: f_hid: wake up readers on disable/unbind

2025-04-11T14:08:33Z

Similar to how it is done in the write path. Add a disabled flag to track the function state and use it to exit the read loops to ensure no readers get stuck when the function is disabled/unbound, protecting against corruption when the waitq and spinlocks are reinitialized in hidg_bind(). Signed-off-by: Peter Korsgaard Link: https://lore.kernel.org/r/20250318152207.330997-1-peter@korsgaard.com Signed-off-by: Greg Kroah-Hartman

usb: gadget: function: move u_f.h to include/linux/usb/func_utils.h

2024-09-03T07:57:08Z

We move the func_utils.h header to include/linux/usb to be able to compile function drivers outside of the drivers/usb/gadget/function directory. Signed-off-by: Michael Grzeschik Link: https://lore.kernel.org/r/20240116-ml-topic-u9p-v12-1-9a27de5160e0@pengutronix.de Signed-off-by: Greg Kroah-Hartman