misc: fastrpc: Don't reference rpmsg_device after remove

As fastrpc_rpmsg_remove() returns the rpdev of the channel context is no longer a valid object, so ensure to update the channel context to no longer reference the old object and guard in the invoke code path against dereferencing it. Signed-off-by: Bjorn Andersson <[email protected]> Signed-off-by: Mayank Chopra <[email protected]> Signed-off-by: Abhinav Asati <[email protected]> Signed-off-by: Vamsi Singamsetty <[email protected]> Signed-off-by: Srinivas Kandagatla <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
johnjwang · Sep 4, 2019 · 2e36987 · 2e36987
1 parent 278d56f
commit 2e36987
Showing 1 changed file with 4 additions and 0 deletions.
diff --git a/drivers/misc/fastrpc.c b/drivers/misc/fastrpc.c
@@ -913,6 +913,9 @@ static int fastrpc_internal_invoke(struct fastrpc_user *fl,  u32 kernel,
 	if (!fl->sctx)
 		return -EINVAL;
 
+	if (!fl->cctx->rpdev)
+		return -EPIPE;
+
 	ctx = fastrpc_context_alloc(fl, kernel, sc, args);
 	if (IS_ERR(ctx))
 		return PTR_ERR(ctx);
@@ -1495,6 +1498,7 @@ static void fastrpc_rpmsg_remove(struct rpmsg_device *rpdev)
 	misc_deregister(&cctx->miscdev);
 	of_platform_depopulate(&rpdev->dev);
 
+	cctx->rpdev = NULL;
 	fastrpc_channel_ctx_put(cctx);
 }