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[nrf fromtree] usb: host: fix control transfer ownership in usbh_req_… - #4607
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…setup usbh_req_setup() waits on a single global semaphore with no mutual exclusion, so two threads can be inside it at once: enumeration runs on the bus thread while the shell and class drivers call in from their own. The first completion wakes an arbitrary waiter, which then reads xfer->err on a transfer that has not finished. Serialize the request with a mutex so the semaphore has one owner at a time. Timing out also released the transfer while the controller still owned it. uhc_ep_dequeue() only requests cancellation: the transfer stays with the driver until it is returned through the completion callback, and the driver may still write into its buffer. Callers such as usbh_req_desc_dev() free that buffer as soon as usbh_req_setup() returns, so a cancelled transfer could land in a recycled net_buf. Wait for the completion callback before freeing, and drop the callback's -ECONNRESET path now that the caller always owns the transfer. Signed-off-by: Ofir Shemesh <ofirshemesh777@gmail.com> (cherry picked from commit 6862873ee28efc6bbac5553de365cd0d92d1b55f)
carlescufi
approved these changes
Oct 14, 2026
tmon-nordic
approved these changes
Oct 15, 2026
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…setup
usbh_req_setup() waits on a single global semaphore with no mutual exclusion, so two threads can be inside it at once: enumeration runs on the bus thread while the shell and class drivers call in from their own. The first completion wakes an arbitrary waiter, which then reads xfer->err on a transfer that has not finished. Serialize the request with a mutex so the semaphore has one owner at a time.
Timing out also released the transfer while the controller still owned it. uhc_ep_dequeue() only requests cancellation: the transfer stays with the driver until it is returned through the completion callback, and the driver may still write into its buffer. Callers such as usbh_req_desc_dev() free that buffer as soon as usbh_req_setup() returns, so a cancelled transfer could land in a recycled net_buf. Wait for the completion callback before freeing, and drop the callback's -ECONNRESET path now that the caller always owns the transfer.
Signed-off-by: Ofir Shemesh ofirshemesh777@gmail.com
(cherry picked from commit 6862873)