CVE-2021-46973

In the Linux kernel, the following vulnerability has been resolved:

net: qrtr: Avoid potential use after free in MHI send

It is possible that the MHI ul_callback will be invoked immediately

following the queueing of the skb for transmission, leading to the

callback decrementing the refcount of the associated sk and freeing the

skb.

As such the dereference of skb and the increment of the sk refcount must

happen before the skb is queued, to avoid the skb to be used after free

and potentially the sk to drop its last refcount..