| Message ID | 20250220095218.970-1-vulab@iscas.ac.cn (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | usb: core: Add error handling in usb_reset_device for autoresume failure | expand |
On Thu, Feb 20, 2025 at 05:52:18PM +0800, Wentao Liang wrote: > In usb_reset_device(), the function continues execution and > calls usb_autosuspend_device() after usb_autosuspend_device fails. > > To fix this, add error handling for usb_autoresume_device() > and return the error code immediately. This ensures that > usb_autosuspend_device() is not called when usb_autoresume_device() > fails, maintaining device state consistency. > > Fixes: 94fcda1f8ab5 ("usbcore: remove unused argument in autosuspend") > Cc: stable@vger.kernel.org # 2.6.20+ > Signed-off-by: Wentao Liang <vulab@iscas.ac.cn> > --- > drivers/usb/core/hub.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c > index 21ac9b464696..f2efdbdd1533 100644 > --- a/drivers/usb/core/hub.c > +++ b/drivers/usb/core/hub.c > @@ -6292,7 +6292,9 @@ int usb_reset_device(struct usb_device *udev) > noio_flag = memalloc_noio_save(); > > /* Prevent autosuspend during the reset */ > - usb_autoresume_device(udev); Have you ever seen this function fail? > + ret = usb_autoresume_device(udev); > + if (ret < 0) if (ret) please. Also, how was this tested? How was it found? thanks, greg k-h
On 20.02.25 10:52, Wentao Liang wrote: > In usb_reset_device(), the function continues execution and > calls usb_autosuspend_device() after usb_autosuspend_device fails. This can only fail if the device needs to be physically resumed. In that case you called usb_reset_device() while you weren't supposed to. The purpose of the call is to keep the counter elevated in order to disable runtime power management temporarily. The code is older than helpers to elevate the count. The correct fix would be to use them rather than handle an error that cannot happen. Regards Oliver
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index 21ac9b464696..f2efdbdd1533 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -6292,7 +6292,9 @@ int usb_reset_device(struct usb_device *udev) noio_flag = memalloc_noio_save(); /* Prevent autosuspend during the reset */ - usb_autoresume_device(udev); + ret = usb_autoresume_device(udev); + if (ret < 0) + goto error_autoresume; if (config) { for (i = 0; i < config->desc.bNumInterfaces; ++i) { @@ -6341,6 +6343,7 @@ int usb_reset_device(struct usb_device *udev) } usb_autosuspend_device(udev); +error_autoresume: memalloc_noio_restore(noio_flag); udev->reset_in_progress = 0; return ret;
In usb_reset_device(), the function continues execution and calls usb_autosuspend_device() after usb_autosuspend_device fails. To fix this, add error handling for usb_autoresume_device() and return the error code immediately. This ensures that usb_autosuspend_device() is not called when usb_autoresume_device() fails, maintaining device state consistency. Fixes: 94fcda1f8ab5 ("usbcore: remove unused argument in autosuspend") Cc: stable@vger.kernel.org # 2.6.20+ Signed-off-by: Wentao Liang <vulab@iscas.ac.cn> --- drivers/usb/core/hub.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)