interconnect: Treat xlate() returning NULL node as an error

[ Upstream commit ad2ab1297d0c80899125a842bb7a078abfe1e6ce ]

Currently, if provider->xlate() or provider->xlate_extended()
"successfully" return a NULL node, then of_icc_get_from_provider() won't
consider that an error and will successfully return the NULL node. This
bypasses error handling in of_icc_get_by_index() and leads to NULL
dereferences in path_find().

This could be avoided by ensuring provider callbacks always return an
error for NULL nodes, but it's better to explicitly protect against this
in the common framework.

Fixes: 87e3031b6fbd ("interconnect: Allow endpoints translation via DT")
Signed-off-by: Mike Tipton <quic_mdtipton@quicinc.com>
Link: https://lore.kernel.org/r/20231025145829.11603-1-quic_mdtipton@quicinc.com
Signed-off-by: Georgi Djakov <djakov@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/interconnect/core.c b/drivers/interconnect/core.c
index dfab160..50bac2d 100644 (file)
--- a/drivers/interconnect/core.c
+++ b/drivers/interconnect/core.c
@@ -395,6 +395,9 @@ struct icc_node_data *of_icc_get_from_provider(struct of_phandle_args *spec)
        }
        mutex_unlock(&icc_lock);
 
+       if (!node)
+               return ERR_PTR(-EINVAL);
+
        if (IS_ERR(node))
                return ERR_CAST(node);