dpaa2-switch: Fix interrupt storm after receiving bad if_id in IRQ handler

Commit 31a7a0bbeb00 ("dpaa2-switch: add bounds check for if_id in IRQ
handler") introduces a range check for if_id to avoid an out-of-bounds
access. If an out-of-bounds if_id is detected, the interrupt status is
not cleared. This may result in an interrupt storm.

Clear the interrupt status after detecting an out-of-bounds if_id to avoid
the problem.

Found by an experimental AI code review agent at Google.

Fixes: 31a7a0bbeb00 ("dpaa2-switch: add bounds check for if_id in IRQ handler")
Cc: Junrui Luo <moonafterrain@outlook.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Link: https://patch.msgid.link/20260227055812.1777915-1-linux@roeck-us.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/ethernet/freescale/dpaa2/dpaa2-switch.c b/drivers/net/ethernet/freescale/dpaa2/dpaa2-switch.c
index fc0e0f36186e9671c50a6cfd3c23c6dc7b5a31f4..52c1cb9cb7e02a3ae951ef20de7672969aa560d0 100644 (file)
--- a/drivers/net/ethernet/freescale/dpaa2/dpaa2-switch.c
+++ b/drivers/net/ethernet/freescale/dpaa2/dpaa2-switch.c
@@ -1533,7 +1533,7 @@ static irqreturn_t dpaa2_switch_irq0_handler_thread(int irq_num, void *arg)
        if_id = (status & 0xFFFF0000) >> 16;
        if (if_id >= ethsw->sw_attr.num_ifs) {
                dev_err(dev, "Invalid if_id %d in IRQ status\n", if_id);
-               goto out;
+               goto out_clear;
        }
        port_priv = ethsw->ports[if_id];
 
@@ -1553,6 +1553,7 @@ static irqreturn_t dpaa2_switch_irq0_handler_thread(int irq_num, void *arg)
                        dpaa2_switch_port_connect_mac(port_priv);
        }
 
+out_clear:
        err = dpsw_clear_irq_status(ethsw->mc_io, 0, ethsw->dpsw_handle,
                                    DPSW_IRQ_INDEX_IF, status);
        if (err)