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

[Greg Kroah-Hartman]

On Sun, May 10, 2020 at 12:45:55AM +0100, Al Viro wrote:
> From: Al Viro 
> 
> in all affected cases addresses are passed only to
> copy_from()_user or copy_to_user().
> 
> Signed-off-by: Al Viro 
> ---
>  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(-)


Reviewed-by: Greg Kroah-Hartman 

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

[Al Viro]

From: Al Viro 

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

Signed-off-by: Al Viro 
---
 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(_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(>read_spinlock, flags);
 
 #define READ_COND (!list_empty(>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(>write_spinlock, flags);
 
 #define WRITE_COND (!hidg->write_pending)
-- 
2.11.0