6.6-stable review patch. If anyone has any objections, please let me know.
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From: Andrey Konovalov andreyknvl@gmail.com
commit e8033bde451eddfb9b1bbd6e2d848c1b5c277222 upstream.
Currently, if a USB request that was queued by Raw Gadget is interrupted (via a signal), wait_for_completion_interruptible returns -ERESTARTSYS. Raw Gadget then attempts to propagate this value to userspace as a return value from its ioctls. However, when -ERESTARTSYS is returned by a syscall handler, the kernel internally restarts the syscall.
This doesn't allow userspace applications to interrupt requests queued by Raw Gadget (which is required when the emulated device is asked to switch altsettings). It also violates the implied interface of Raw Gadget that a single ioctl must only queue a single USB request.
Instead, make Raw Gadget do what GadgetFS does: check whether the request was interrupted (dequeued with status == -ECONNRESET) and report -EINTR to userspace.
Fixes: f2c2e717642c ("usb: gadget: add raw-gadget interface") Cc: stable stable@kernel.org Signed-off-by: Andrey Konovalov andreyknvl@gmail.com Link: https://lore.kernel.org/r/0db45b1d7cc466e3d4d1ab353f61d63c977fbbc5.169835042... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/usb/gadget/legacy/raw_gadget.c | 26 ++++++++++++++++---------- 1 file changed, 16 insertions(+), 10 deletions(-)
--- a/drivers/usb/gadget/legacy/raw_gadget.c +++ b/drivers/usb/gadget/legacy/raw_gadget.c @@ -663,12 +663,12 @@ static int raw_process_ep0_io(struct raw if (WARN_ON(in && dev->ep0_out_pending)) { ret = -ENODEV; dev->state = STATE_DEV_FAILED; - goto out_done; + goto out_unlock; } if (WARN_ON(!in && dev->ep0_in_pending)) { ret = -ENODEV; dev->state = STATE_DEV_FAILED; - goto out_done; + goto out_unlock; }
dev->req->buf = data; @@ -683,7 +683,7 @@ static int raw_process_ep0_io(struct raw "fail, usb_ep_queue returned %d\n", ret); spin_lock_irqsave(&dev->lock, flags); dev->state = STATE_DEV_FAILED; - goto out_done; + goto out_queue_failed; }
ret = wait_for_completion_interruptible(&dev->ep0_done); @@ -692,13 +692,16 @@ static int raw_process_ep0_io(struct raw usb_ep_dequeue(dev->gadget->ep0, dev->req); wait_for_completion(&dev->ep0_done); spin_lock_irqsave(&dev->lock, flags); - goto out_done; + if (dev->ep0_status == -ECONNRESET) + dev->ep0_status = -EINTR; + goto out_interrupted; }
spin_lock_irqsave(&dev->lock, flags); - ret = dev->ep0_status;
-out_done: +out_interrupted: + ret = dev->ep0_status; +out_queue_failed: dev->ep0_urb_queued = false; out_unlock: spin_unlock_irqrestore(&dev->lock, flags); @@ -1067,7 +1070,7 @@ static int raw_process_ep_io(struct raw_ "fail, usb_ep_queue returned %d\n", ret); spin_lock_irqsave(&dev->lock, flags); dev->state = STATE_DEV_FAILED; - goto out_done; + goto out_queue_failed; }
ret = wait_for_completion_interruptible(&done); @@ -1076,13 +1079,16 @@ static int raw_process_ep_io(struct raw_ usb_ep_dequeue(ep->ep, ep->req); wait_for_completion(&done); spin_lock_irqsave(&dev->lock, flags); - goto out_done; + if (ep->status == -ECONNRESET) + ep->status = -EINTR; + goto out_interrupted; }
spin_lock_irqsave(&dev->lock, flags); - ret = ep->status;
-out_done: +out_interrupted: + ret = ep->status; +out_queue_failed: ep->urb_queued = false; out_unlock: spin_unlock_irqrestore(&dev->lock, flags);