[PATCH net v2] net: airoha: fix potential use-after-free in airoha_npu_get()

[PATCH net v2] net: airoha: fix potential use-after-free in airoha_npu_get()

[Alok Tiwari]

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>
---
v1->v2
call of_node_put(np) after printing np->name, as per Andrew's comment.
https://lore.kernel.org/all/555d7fb6-091e-4c10-bfea-85898e644481@lunn.ch
---
 drivers/net/ethernet/airoha/airoha_npu.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/airoha/airoha_npu.c b/drivers/net/ethernet/airoha/airoha_npu.c
index 0e5b8c21b9aa8..1e58a4aeb9a0c 100644
--- 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");
-- 
2.46.0

Re: [PATCH net v2] net: airoha: fix potential use-after-free in airoha_npu_get()

[Andrew Lunn]

On Tue, Jul 15, 2025 at 07:30:58AM -0700, Alok Tiwari wrote:
> 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>

    Andrew

Re: [PATCH net v2] net: airoha: fix potential use-after-free in airoha_npu_get()

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net.git (main)
by Jakub Kicinski <kuba@kernel.org>:

On Tue, 15 Jul 2025 07:30:58 -0700 you wrote:
> 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.
> 
> [...]

Here is the summary with links:
  - [net,v2] net: airoha: fix potential use-after-free in airoha_npu_get()
    https://git.kernel.org/netdev/net/c/3cd582e7d078

You are awesome, thank you!
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