msm: adsprpc: Handle UAF in fastrpc internal munmap

Added reference count for contex map indicate memory under used
in remote call. And, this memory would not removed in internal
unmap to avoid UAF.

Issue: FP3SEC-1185
Change-Id: Ieb4ff6b298ff9c48953bc5b3539fdfe19a14b442
Acked-by: DEEPAK SANNAPAREDDY <sdeeredd@qti.qualcomm.com>
Signed-off-by: Vamsi Krishna Gattupalli <quic_vgattupa@quicinc.com>
(cherry picked from commit 103b88d461f00a60f31de8bc8aa4a04d87f5b5ab)
1 file changed