[PATCH 18/20] usb: get rid of pointless access_ok() calls

From: Al Viro
Date: Sat May 09 2020 - 19:46:40 EST


From: Al Viro <viro@xxxxxxxxxxxxxxxxxx>

in all affected cases addresses are passed only to
copy_from()_user or copy_to_user().

Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
---
drivers/usb/core/devices.c | 2 --
drivers/usb/core/devio.c | 9 ---------
drivers/usb/gadget/function/f_hid.c | 6 ------
3 files changed, 17 deletions(-)

diff --git a/drivers/usb/core/devices.c b/drivers/usb/core/devices.c
index 44f28a114c2b..94b6fa6e585e 100644
--- a/drivers/usb/core/devices.c
+++ b/drivers/usb/core/devices.c
@@ -598,8 +598,6 @@ static ssize_t usb_device_read(struct file *file, char __user *buf,
return -EINVAL;
if (nbytes <= 0)
return 0;
- if (!access_ok(buf, nbytes))
- return -EFAULT;

mutex_lock(&usb_bus_idr_lock);
/* print devices for all busses */
diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c
index 6833c918abce..544769807ab8 100644
--- a/drivers/usb/core/devio.c
+++ b/drivers/usb/core/devio.c
@@ -1127,11 +1127,6 @@ static int proc_control(struct usb_dev_state *ps, void __user *arg)
ctrl.bRequestType, ctrl.bRequest, ctrl.wValue,
ctrl.wIndex, ctrl.wLength);
if (ctrl.bRequestType & 0x80) {
- if (ctrl.wLength && !access_ok(ctrl.data,
- ctrl.wLength)) {
- ret = -EINVAL;
- goto done;
- }
pipe = usb_rcvctrlpipe(dev, 0);
snoop_urb(dev, NULL, pipe, ctrl.wLength, tmo, SUBMIT, NULL, 0);

@@ -1216,10 +1211,6 @@ static int proc_bulk(struct usb_dev_state *ps, void __user *arg)
}
tmo = bulk.timeout;
if (bulk.ep & 0x80) {
- if (len1 && !access_ok(bulk.data, len1)) {
- ret = -EINVAL;
- goto done;
- }
snoop_urb(dev, NULL, pipe, len1, tmo, SUBMIT, NULL, 0);

usb_unlock_device(dev);
diff --git a/drivers/usb/gadget/function/f_hid.c b/drivers/usb/gadget/function/f_hid.c
index f3816a5c861e..df671acdd464 100644
--- a/drivers/usb/gadget/function/f_hid.c
+++ b/drivers/usb/gadget/function/f_hid.c
@@ -252,9 +252,6 @@ static ssize_t f_hidg_read(struct file *file, char __user *buffer,
if (!count)
return 0;

- if (!access_ok(buffer, count))
- return -EFAULT;
-
spin_lock_irqsave(&hidg->read_spinlock, flags);

#define READ_COND (!list_empty(&hidg->completed_out_req))
@@ -339,9 +336,6 @@ static ssize_t f_hidg_write(struct file *file, const char __user *buffer,
unsigned long flags;
ssize_t status = -ENOMEM;

- if (!access_ok(buffer, count))
- return -EFAULT;
-
spin_lock_irqsave(&hidg->write_spinlock, flags);

#define WRITE_COND (!hidg->write_pending)
--
2.11.0