net: airoha: fix potential use-after-free in airoha_npu_get()

np->name was being used after calling of_node_put(np), which
releases the node and can lead to a use-after-free bug.
Previously, of_node_put(np) was called unconditionally after
of_find_device_by_node(np), which could result in a use-after-free if
pdev is NULL.

This patch moves of_node_put(np) after the error check to ensure
the node is only released after both the error and success cases
are handled appropriately, preventing potential resource issues.

Fixes: 23290c7bc190 ("net: airoha: Introduce Airoha NPU support")
Signed-off-by: Alok Tiwari <alok.a.tiwari@oracle.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://patch.msgid.link/20250715143102.3458286-1-alok.a.tiwari@oracle.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/ethernet/airoha/airoha_npu.c b/drivers/net/ethernet/airoha/airoha_npu.c
index 0e5b8c21b9aa8bacdfb2e1572afe4324003e8279..1e58a4aeb9a0c2dc722f7408338c114b333c9089 100644 (file)
--- a/drivers/net/ethernet/airoha/airoha_npu.c
+++ b/drivers/net/ethernet/airoha/airoha_npu.c
@@ -401,12 +401,13 @@ struct airoha_npu *airoha_npu_get(struct device *dev, dma_addr_t *stats_addr)
                return ERR_PTR(-ENODEV);
 
        pdev = of_find_device_by_node(np);
-       of_node_put(np);
 
        if (!pdev) {
                dev_err(dev, "cannot find device node %s\n", np->name);
+               of_node_put(np);
                return ERR_PTR(-ENODEV);
        }
+       of_node_put(np);
 
        if (!try_module_get(THIS_MODULE)) {
                dev_err(dev, "failed to get the device driver module\n");