In the Linux kernel, the following vulnerability has been resolved:
drbd: fix null-pointer dereference on local read error
In drbd_request_endio(), READ_COMPLETED_WITH_ERROR is passed to
__req_mod() with a NULL peer_device:
__req_mod(req, what, NULL, &m);
The READ_COMPLETED_WITH_ERROR handler then unconditionally passes this
NULL peer_device to drbd_set_out_of_sync(), which dereferences it,
causing a null-pointer dereference.
Fix this by obtaining the peer_device via first_peer_device(device),
matching how drbd_req_destroy() handles the same situation.