An issue was discovered in the Linux kernel through 5.11.6. fastrpc_internal_invoke in drivers/misc/fastrpc.c does not prevent user applications from sending kernel RPC messages, aka CID-20c40794eb85. This is a related issue to CVE-2019-2308.

User application could potentially make RPC call to the fastrpc driver and the driver will allow the message to go through to the remote subsystem in Snapdragon Auto, Snapdragon Consumer IOT, Snapdragon Industrial IOT, Snapdragon Mobile, Snapdragon Voice & Music, Snapdragon Wearables in MDM9150, MDM9607, MDM9650, MSM8909W, MSM8996AU, QCS405, QCS605, Qualcomm 215, SD 425, SD 427, SD 430, SD 435, SD 439 / SD 429, SD 450, SD 625, SD 632, SD 636, SD 665, SD 675, SD 712 / SD 710 / SD 670, SD 730, SD 820A, SD 835, SD 845 / SD 850, SD 855, SDA660, SDM439, SDM630, SDM660, SDX20, SDX24