Messages in this thread Patch in this message | | | Date | Mon, 11 Jul 2011 11:21:18 +0200 (CEST) | From | Jesper Juhl <> | Subject | [PATCH] USB: Avoid NULL pointer dereference in usb_disconnect() |
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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@chaosbits.net> --- 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@chaosbits.net> http://www.chaosbits.net/ Don't top-post http://www.catb.org/jargon/html/T/top-post.html Plain text mails only, please.
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