In the Linux kernel, the following vulnerability has been resolved:
staging: nvec: fix use-after-free in nvec_rx_completed()
In nvec_rx_completed(), when an incomplete RX transfer is detected,
nvec_msg_free() is called to return the message back to the pool by
clearing its ‘used’ atomic flag. Immediately after this, the code
accesses nvec->rx->data[0] to check the message type.
Since nvec_msg_free() marks the pool slot as available via atomic_set(),
any concurrent or subsequent call to nvec_msg_alloc() could claim that
same slot and overwrite its data[] array. Reading nvec->rx->data[0] after
freeing the message is therefore a use-after-free.
Fix this by saving the message type byte before calling nvec_msg_free(),
then using the saved value for the battery quirk check.
