[PATCH 5.4 26/47] interconnect: Treat xlate() returning NULL node as an error

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

5.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Mike Tipton <quic_mdtipton@quicinc.com>

[ 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>
---
 drivers/interconnect/core.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/interconnect/core.c b/drivers/interconnect/core.c
index be3fa1ac4261c..8f6dfa6b6e4dc 100644
--- a/drivers/interconnect/core.c
+++ b/drivers/interconnect/core.c
@@ -280,6 +280,9 @@ static struct icc_node *of_icc_get_from_provider(struct of_phandle_args *spec)
 	}
 	mutex_unlock(&icc_lock);
 
+	if (!node)
+		return ERR_PTR(-EINVAL);
+
 	return node;
 }
 
-- 
2.43.0