diff options
| author | Phil Elwell <phil@raspberrypi.com> | 2021-07-23 18:59:30 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-07-27 15:54:51 +0200 |
| commit | 2867652e4766360adf14dfda3832455e04964f2a (patch) | |
| tree | f4c9d2a69888a2a21e4ebb1aa39d319633c5add8 /drivers/usb | |
| parent | fa4a8dcfd51b911f101ebc461dfe22230b74dd64 (diff) | |
usb: gadget: f_hid: fixed NULL pointer dereference
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/a6e47d5f4efbd2ea6a0b6565cd2f9b7bb217ded5 [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>
Diffstat (limited to 'drivers/usb')
| -rw-r--r-- | drivers/usb/gadget/function/f_hid.c | 26 |
1 files changed, 20 insertions, 6 deletions
diff --git a/drivers/usb/gadget/function/f_hid.c b/drivers/usb/gadget/function/f_hid.c index 02683ac0719d..08e73e8127b1 100644 --- a/drivers/usb/gadget/function/f_hid.c +++ b/drivers/usb/gadget/function/f_hid.c @@ -338,6 +338,11 @@ static ssize_t f_hidg_write(struct file *file, const char __user *buffer, 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 */ @@ -358,8 +363,14 @@ 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"); @@ -387,14 +398,17 @@ 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: |