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

firmware: arm_scmi: Unwind P2A receiver mailbox setup failure

mailbox_chan_setup() can request an additional P2A receiver channel after
successfully acquiring the primary P2A channel. If that later request
fails, the function returns immediately and leaves the primary channel
allocated.

Unwind the primary mailbox channel before returning the error so probe
deferral or other setup failures do not leave the channel busy for later
probe attempts.