[PATCH] USB: Avoid NULL pointer dereference in usb_disconnect()
From: Jesper Juhl
Date: Mon Jul 11 2011 - 05:21:30 EST
If, in drivers/usb/core/hub.c::usb_disconnect(), 'udev' is NULL, then
we'll never get to the printing of a debug message and returning from
the function since we'll have already dereferenced the NULL pointer in
the bus_to_hcd(udev->bus) call.
This patch moves the dereference to after the test for NULL, thus
avoiding that potential crash.
Signed-off-by: Jesper Juhl <jj@xxxxxxxxxxxxx>
---
drivers/usb/core/hub.c | 4 +++-
1 files changed, 3 insertions(+), 1 deletions(-)
disclaimer: compile tested only.
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index a428aa0..0a98c76 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -1634,13 +1634,15 @@ void usb_disconnect(struct usb_device **pdev)
{
struct usb_device *udev = *pdev;
int i;
- struct usb_hcd *hcd = bus_to_hcd(udev->bus);
+ struct usb_hcd *hcd;
if (!udev) {
pr_debug ("%s nodev\n", __func__);
return;
}
+ hcd = bus_to_hcd(udev->bus);
+
/* mark the device as inactive, so any further urb submissions for
* this device (and any of its children) will fail immediately.
* this quiesces everything except pending urbs.
--
1.7.6
--
Jesper Juhl <jj@xxxxxxxxxxxxx> http://www.chaosbits.net/
Don't top-post http://www.catb.org/jargon/html/T/top-post.html
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