2021-11-02 07:47:38

by Haimin Zhang

Subject: [PATCH] USB: array-index-out-of-bounds in ehci_brcm_hub_control

There isn't enough check parameter `wIndex` in the function
`ehci_brcm_hub_control`;due to the size of array `port_status`
is 15, so it may lead to out of bounds.

Signed-off-by: Haimin Zhang <[email protected]>
Reported-by: TCS Robot <[email protected]>
---
drivers/usb/host/ehci-brcm.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/host/ehci-brcm.c b/drivers/usb/host/ehci-brcm.c
index d3626bfa966b..4ca3eb9fcda9 100644
--- a/drivers/usb/host/ehci-brcm.c
+++ b/drivers/usb/host/ehci-brcm.c
@@ -63,7 +63,8 @@ static int ehci_brcm_hub_control(
unsigned long flags;
int retval, irq_disabled = 0;

- status_reg = &ehci->regs->port_status[(wIndex & 0xff) - 1];
+ if (wIndex && wIndex <= ports)
+ status_reg = &ehci->regs->port_status[(wIndex & 0xff) - 1];

/*
* RESUME is cleared when GetPortStatus() is called 20ms after start
--

2021-11-02 19:25:13

by Alan Stern

Subject: Re: [PATCH] USB: array-index-out-of-bounds in ehci_brcm_hub_control

On Tue, Nov 02, 2021 at 03:44:46PM +0800, Haimin Zhang wrote:
> There isn't enough check parameter `wIndex` in the function
> `ehci_brcm_hub_control`;due to the size of array `port_status`
> is 15, so it may lead to out of bounds.
>
> Signed-off-by: Haimin Zhang <[email protected]>
> Reported-by: TCS Robot <[email protected]>
> ---
> drivers/usb/host/ehci-brcm.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/usb/host/ehci-brcm.c b/drivers/usb/host/ehci-brcm.c
> index d3626bfa966b..4ca3eb9fcda9 100644
> --- a/drivers/usb/host/ehci-brcm.c
> +++ b/drivers/usb/host/ehci-brcm.c
> @@ -63,7 +63,8 @@ static int ehci_brcm_hub_control(
> unsigned long flags;
> int retval, irq_disabled = 0;
>
> - status_reg = &ehci->regs->port_status[(wIndex & 0xff) - 1];
> + if (wIndex && wIndex <= ports)
> + status_reg = &ehci->regs->port_status[(wIndex & 0xff) - 1];

This isn't quite right because it won't work properly if the upper byte
of wIndex is nonzero. You should do something like:

u32 temp;

temp = (wIndex & 0xff) - 1;
if (temp < ports)
status_reg = &ehci->regs->port_status[temp];

Alan Stern