[PATCH 3/8] of/irq: Fix device node refcount leakage in API of_irq_parse_raw()

[Zijun Hu]

From: Zijun Hu <quic_zijuhu@xxxxxxxxxxx>

of_irq_parse_raw() will return when meet condition (@ipar == @newpar)
but Refcount of device node @out_irq->np was increased twice when
directly return there, hence causes @out_irq->np refcount leakage.

Fix by putting @out_irq->np refcount before returning there.

Fixes: 041284181226 ("of/irq: Allow matching of an interrupt-map local to an interrupt controller")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Zijun Hu <quic_zijuhu@xxxxxxxxxxx>
---
 drivers/of/irq.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/of/irq.c b/drivers/of/irq.c
index 758eb9b3714868112e83469d131b244ce77d4e82..cb39624a5e7799b9d2f4525f42dac4cd921ab403 100644
--- a/drivers/of/irq.c
+++ b/drivers/of/irq.c
@@ -310,6 +310,12 @@ int of_irq_parse_raw(const __be32 *addr, struct of_phandle_args *out_irq)
 		addrsize = (imap - match_array) - intsize;
 
 		if (ipar == newpar) {
+			/*
+			 * Has got @ipar's refcount, but the refcount was
+			 * got again by of_irq_parse_imap_parent() via its
+			 * alias @newpair.
+			 */
+			of_node_put(ipar);
 			pr_debug("%pOF interrupt-map entry to self\n", ipar);
 			return 0;
 		}

-- 
2.34.1