[PATCH 6.12.y 2/3] net: dsa: microchip: Don't free uninitialized ksz_irq

[Sasha Levin <sashal@kernel.org>]

From: "Bastien Curutchet (Schneider Electric)" <bastien.curutchet@bootlin.com>

[ Upstream commit 25b62cc5b22c45face094ae3e8717258e46d1d19 ]

If something goes wrong at setup, ksz_irq_free() can be called on
uninitialized ksz_irq (for example when ksz_ptp_irq_setup() fails). It
leads to freeing uninitialized IRQ numbers and/or domains.

Use dsa_switch_for_each_user_port_continue_reverse() in the error path
to iterate only over the fully initialized ports.

Cc: stable@vger.kernel.org
Fixes: cc13ab18b201 ("net: dsa: microchip: ptp: enable interrupt for timestamping")
Signed-off-by: Bastien Curutchet (Schneider Electric) <bastien.curutchet@bootlin.com>
Link: https://patch.msgid.link/20251120-ksz-fix-v6-3-891f80ae7f8f@bootlin.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Stable-dep-of: 0f80e21bf622 ("net: dsa: microchip: Free previously initialized ports on init failures")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/dsa/microchip/ksz_common.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/dsa/microchip/ksz_common.c b/drivers/net/dsa/microchip/ksz_common.c
index 664e3114a5bd0..4a7cb9dca3243 100644
--- a/drivers/net/dsa/microchip/ksz_common.c
+++ b/drivers/net/dsa/microchip/ksz_common.c
@@ -2608,7 +2608,7 @@ static int ksz_setup(struct dsa_switch *ds)
 			ksz_ptp_irq_free(ds, dp->index);
 out_pirq:
 	if (dev->irq > 0)
-		dsa_switch_for_each_user_port(dp, dev->ds)
+		dsa_switch_for_each_user_port_continue_reverse(dp, dev->ds)
 			ksz_irq_free(&dev->ports[dp->index].pirq);
 out_girq:
 	if (dev->irq > 0)
-- 
2.51.0