[PATCH 6.12 176/460] net: dsa: microchip: Fix error path in PTP IRQ setup

Greg Kroah-Hartman
2026-03-23T14:21:05Z

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

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

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

commit 99c8c16a4aad0b37293cae213e15957c573cf79b upstream.

If request_threaded_irq() fails during the PTP message IRQ setup, the
newly created IRQ mapping is never disposed. Indeed, the
ksz_ptp_irq_setup()'s error path only frees the mappings that were
successfully set up.

Dispose the newly created mapping if the associated
request_threaded_irq() fails at setup.

Cc: stable@vger.kernel.org
Fixes: d0b8fec8ae505 ("net: dsa: microchip: Fix symetry in ksz_ptp_msg_irq_{setup/free}()")
Signed-off-by: Bastien Curutchet (Schneider Electric) <bastien.curutchet@bootlin.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Link: https://patch.msgid.link/20260309-ksz-ptp-irq-fix-v1-1-757b3b985955@bootlin.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/net/dsa/microchip/ksz_ptp.c | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)

--- a/drivers/net/dsa/microchip/ksz_ptp.c
+++ b/drivers/net/dsa/microchip/ksz_ptp.c
@@ -1101,6 +1101,7 @@ static int ksz_ptp_msg_irq_setup(struct
const struct ksz_dev_ops *ops = port->ksz_dev->dev_ops;
struct ksz_irq *ptpirq = &port->ptpirq;
struct ksz_ptp_irq *ptpmsg_irq;
+ int ret;

ptpmsg_irq = &port->ptpmsg_irq[n];
ptpmsg_irq->num = irq_create_mapping(ptpirq->domain, n);
@@ -1112,9 +1113,13 @@ static int ksz_ptp_msg_irq_setup(struct

snprintf(ptpmsg_irq->name, sizeof(ptpmsg_irq->name), name[n]);

- return request_threaded_irq(ptpmsg_irq->num, NULL,
- ksz_ptp_msg_thread_fn, IRQF_ONESHOT,
- ptpmsg_irq->name, ptpmsg_irq);
+ ret = request_threaded_irq(ptpmsg_irq->num, NULL,
+ ksz_ptp_msg_thread_fn, IRQF_ONESHOT,
+ ptpmsg_irq->name, ptpmsg_irq);
+ if (ret)
+ irq_dispose_mapping(ptpmsg_irq->num);
+
+ return ret;
}

int ksz_ptp_irq_setup(struct dsa_switch *ds, u8 p)