Hi Jack,
在 2018年02月06日 02:17, Jack Pham 写道:
Hi William,
On Mon, Feb 05, 2018 at 07:33:38PM +0800, William Wu wrote:
Refer to the USB 3.0 spec '9.6.7 SuperSpeed Endpoint Companion',
the companion descriptor follows the standard endpoint descriptor.
This descriptor is only defined for SuperSpeed endpoints. The
f_fs driver gets the address of the companion descriptor via
'ds + USB_DT_ENDPOINT_SIZE', and actually, the ds variable is
a pointer to the struct usb_endpoint_descriptor, so the offset
of the companion descriptor which we get is USB_DT_ENDPOINT_SIZE *
sizeof(struct usb_endpoint_descriptor), the wrong offset is 63
bytes. This cause out-of-bound with the following error log if
CONFIG_KASAN and CONFIG_SLUB_DEBUG is enabled on Rockchip RK3399
Evaluation Board.
android_work: sent uevent USB_STATE=CONNECTED
configfs-gadget gadget: super-speed config #1: b
==================================================================
BUG: KASAN: slab-out-of-bounds in ffs_func_set_alt+0x230/0x398
Read of size 1 at addr ffffffc0ce2d0b10 by task irq/224-dwc3/364
Memory state around the buggy address:
ffffffc0ce2d0a00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffffffc0ce2d0a80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffffffc0ce2d0b00: 00 04 fc fc fc fc fc fc fc fc fc fc fc fc fc fc
^
ffffffc0ce2d0b80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffffffc0ce2d0c00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================
Disabling lock debugging due to kernel taint
android_work: sent uevent USB_STATE=CONFIGURED
This patch adds struct usb_endpoint_descriptor * -> u8 * type conversion
for ds variable, then we can get the correct address of comp_desc
with offset USB_DT_ENDPOINT_SIZE bytes.
Signed-off-by: William Wu <william.wu@xxxxxxxxxxxxxx>
---
drivers/usb/gadget/function/f_fs.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c
index 6756472..f13ead0 100644
--- a/drivers/usb/gadget/function/f_fs.c
+++ b/drivers/usb/gadget/function/f_fs.c
@@ -1882,8 +1882,8 @@ static int ffs_func_eps_enable(struct ffs_function *func)
ep->ep->desc = ds;
if (needs_comp_desc) {
- comp_desc = (struct usb_ss_ep_comp_descriptor *)(ds +
- USB_DT_ENDPOINT_SIZE);
+ comp_desc = (struct usb_ss_ep_comp_descriptor *)
+ ((u8 *)ds + USB_DT_ENDPOINT_SIZE);
ep->ep->maxburst = comp_desc->bMaxBurst + 1;
ep->ep->comp_desc = comp_desc;
}
Please see my alternative fix for this. I proposed changing this
function to use config_ep_by_speed() instead.
https://www.spinics.net/lists/linux-usb/msg165149.html
Thanks for your great job!
Your patch seems good, I will test your patch on my RK3399-EVB board.
William
Jack
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