[PATCH 5.15 070/570] dpaa2-switch: Fix interrupt storm after receiving bad if_id in IRQ handler

Greg Kroah-Hartman
2026-04-13T16:21:07Z

From: Guenter Roeck <linux@roeck-us.net>

[ Upstream commit 74badb9c20b1a9c02a95c735c6d3cd6121679c93 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/ethernet/freescale/dpaa2/dpaa2-switch.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/freescale/dpaa2/dpaa2-switch.c b/drivers/net/ethernet/freescale/dpaa2/dpaa2-switch.c
index 9713d04238138..3cc844a61cb88 100644
--- a/drivers/net/ethernet/freescale/dpaa2/dpaa2-switch.c
+++ b/drivers/net/ethernet/freescale/dpaa2/dpaa2-switch.c
@@ -1532,7 +1532,7 @@ 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];

@@ -1555,6 +1555,7 @@ static irqreturn_t dpaa2_switch_irq0_handler_thread(int irq_num, void *arg)
rtnl_unlock();
}

+out_clear:
err = dpsw_clear_irq_status(ethsw->mc_io, 0, ethsw->dpsw_handle,
DPSW_IRQ_INDEX_IF, status);
if (err)
--
2.51.0