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.
https://git.kernel.org/stable/c/91df51d2df0ca4fd3281f73626341563d64a98a5
https://git.kernel.org/stable/c/6f1d1614f841d91a4169db65812ffd1271735b42
https://git.kernel.org/stable/c/4e8935053ba389ae8d6685c10854d8021931bd89
https://git.kernel.org/stable/c/1e906c08594c8f9a6a524f38ede2c4e051196106
https://git.kernel.org/stable/c/0d195d3b205ca90db30d70d09d7bb6909aac178f