From: Phil Elwell phil@raspberrypi.com
commit 2867652e4766360adf14dfda3832455e04964f2a upstream.
Disconnecting and reconnecting the USB cable can lead to crashes and a variety of kernel log spam.
The problem was found and reproduced on the Raspberry Pi [1] and the original fix was created in Raspberry's own fork [2].
Link: https://github.com/raspberrypi/linux/issues/3870 [1] Link: https://github.com/raspberrypi/linux/commit/a6e47d5f4efbd2ea6a0b6565cd2f9b7b... [2] Signed-off-by: Maxim Devaev mdevaev@gmail.com Signed-off-by: Phil Elwell phil@raspberrypi.com Cc: stable stable@vger.kernel.org Link: https://lore.kernel.org/r/20210723155928.210019-1-mdevaev@gmail.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/usb/gadget/function/f_hid.c | 26 ++++++++++++++++++++------ 1 file changed, 20 insertions(+), 6 deletions(-)
--- a/drivers/usb/gadget/function/f_hid.c +++ b/drivers/usb/gadget/function/f_hid.c @@ -339,6 +339,11 @@ static ssize_t f_hidg_write(struct file
spin_lock_irqsave(&hidg->write_spinlock, flags);
+ if (!hidg->req) { + spin_unlock_irqrestore(&hidg->write_spinlock, flags); + return -ESHUTDOWN; + } + #define WRITE_COND (!hidg->write_pending) try_again: /* write queue */ @@ -359,8 +364,14 @@ try_again: count = min_t(unsigned, count, hidg->report_length);
spin_unlock_irqrestore(&hidg->write_spinlock, flags); - status = copy_from_user(req->buf, buffer, count);
+ if (!req) { + ERROR(hidg->func.config->cdev, "hidg->req is NULL\n"); + status = -ESHUTDOWN; + goto release_write_pending; + } + + status = copy_from_user(req->buf, buffer, count); if (status != 0) { ERROR(hidg->func.config->cdev, "copy_from_user error\n"); @@ -388,14 +399,17 @@ try_again:
spin_unlock_irqrestore(&hidg->write_spinlock, flags);
+ if (!hidg->in_ep->enabled) { + ERROR(hidg->func.config->cdev, "in_ep is disabled\n"); + status = -ESHUTDOWN; + goto release_write_pending; + } + status = usb_ep_queue(hidg->in_ep, req, GFP_ATOMIC); - if (status < 0) { - ERROR(hidg->func.config->cdev, - "usb_ep_queue error on int endpoint %zd\n", status); + if (status < 0) goto release_write_pending; - } else { + else status = count; - }
return status; release_write_pending: