[PATCH net-next] net: ti: icssm-prueth: unwind cleanly in probe()

[PATCH net-next] net: ti: icssm-prueth: unwind cleanly in probe()

[Dan Carpenter]

This error handling triggers a Smatch warning:

    drivers/net/ethernet/ti/icssm/icssm_prueth.c:1574 icssm_prueth_probe()
    warn: 'prueth->pru1' is an error pointer or valid

The warning is harmless because the pru_rproc_put() function has an
IS_ERR_OR_NULL() check built in.  However, there is a small bug if
syscon_regmap_lookup_by_phandle() fails.  In that case we should call
of_node_put() on eth0_node and eth1_node.

It's a little bit easier to re-write this code to only free things which
we know have been allocated successfully.

Fixes: 511f6c1ae093 ("net: ti: icssm-prueth: Adds ICSSM Ethernet driver")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
---
 drivers/net/ethernet/ti/icssm/icssm_prueth.c | 30 +++++++++-----------
 1 file changed, 14 insertions(+), 16 deletions(-)

diff --git a/drivers/net/ethernet/ti/icssm/icssm_prueth.c b/drivers/net/ethernet/ti/icssm/icssm_prueth.c
index 65d0b792132d..293b7af04263 100644
--- a/drivers/net/ethernet/ti/icssm/icssm_prueth.c
+++ b/drivers/net/ethernet/ti/icssm/icssm_prueth.c
@@ -1390,7 +1390,8 @@ static int icssm_prueth_probe(struct platform_device *pdev)
 	prueth->mii_rt = syscon_regmap_lookup_by_phandle(np, "ti,mii-rt");
 	if (IS_ERR(prueth->mii_rt)) {
 		dev_err(dev, "couldn't get mii-rt syscon regmap\n");
-		return -ENODEV;
+		ret = PTR_ERR(prueth->mii_rt);
+		goto put_eth;
 	}
 
 	if (eth0_node) {
@@ -1398,7 +1399,7 @@ static int icssm_prueth_probe(struct platform_device *pdev)
 		if (IS_ERR(prueth->pru0)) {
 			ret = PTR_ERR(prueth->pru0);
 			dev_err_probe(dev, ret, "unable to get PRU0");
-			goto put_pru;
+			goto put_eth;
 		}
 	}
 
@@ -1407,7 +1408,7 @@ static int icssm_prueth_probe(struct platform_device *pdev)
 		if (IS_ERR(prueth->pru1)) {
 			ret = PTR_ERR(prueth->pru1);
 			dev_err_probe(dev, ret, "unable to get PRU1");
-			goto put_pru;
+			goto put_pru0;
 		}
 	}
 
@@ -1415,7 +1416,7 @@ static int icssm_prueth_probe(struct platform_device *pdev)
 	if (IS_ERR(pruss)) {
 		ret = PTR_ERR(pruss);
 		dev_err(dev, "unable to get pruss handle\n");
-		goto put_pru;
+		goto put_pru1;
 	}
 	prueth->pruss = pruss;
 
@@ -1569,18 +1570,15 @@ static int icssm_prueth_probe(struct platform_device *pdev)
 	}
 	pruss_put(prueth->pruss);
 
-put_pru:
-	if (eth1_node) {
-		if (prueth->pru1)
-			pru_rproc_put(prueth->pru1);
-		of_node_put(eth1_node);
-	}
-
-	if (eth0_node) {
-		if (prueth->pru0)
-			pru_rproc_put(prueth->pru0);
-		of_node_put(eth0_node);
-	}
+put_pru1:
+	if (eth1_node)
+		pru_rproc_put(prueth->pru1);
+put_pru0:
+	if (eth0_node)
+		pru_rproc_put(prueth->pru0);
+put_eth:
+	of_node_put(eth1_node);
+	of_node_put(eth0_node);
 
 	return ret;
 }
-- 
2.51.0

Re: [PATCH net-next] net: ti: icssm-prueth: unwind cleanly in probe()

[Simon Horman]

On Thu, Sep 18, 2025 at 12:48:26PM +0300, Dan Carpenter wrote:
> This error handling triggers a Smatch warning:
> 
>     drivers/net/ethernet/ti/icssm/icssm_prueth.c:1574 icssm_prueth_probe()
>     warn: 'prueth->pru1' is an error pointer or valid
> 
> The warning is harmless because the pru_rproc_put() function has an
> IS_ERR_OR_NULL() check built in.  However, there is a small bug if
> syscon_regmap_lookup_by_phandle() fails.  In that case we should call
> of_node_put() on eth0_node and eth1_node.
> 
> It's a little bit easier to re-write this code to only free things which
> we know have been allocated successfully.
> 
> Fixes: 511f6c1ae093 ("net: ti: icssm-prueth: Adds ICSSM Ethernet driver")
> Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>

Thanks Dan.

I'm pretty sure I reviewed this code at some point.
Sorry for not noticing this problem then.

Reviewed-by: Simon Horman <horms@kernel.org>

...

Re: [PATCH net-next] net: ti: icssm-prueth: unwind cleanly in probe()

[Jakub Kicinski]

On Thu, 18 Sep 2025 12:48:26 +0300 Dan Carpenter wrote:
> This error handling triggers a Smatch warning:
> 
>     drivers/net/ethernet/ti/icssm/icssm_prueth.c:1574 icssm_prueth_probe()
>     warn: 'prueth->pru1' is an error pointer or valid
> 
> The warning is harmless because the pru_rproc_put() function has an
> IS_ERR_OR_NULL() check built in.  However, there is a small bug if
> syscon_regmap_lookup_by_phandle() fails.  In that case we should call
> of_node_put() on eth0_node and eth1_node.
> 
> It's a little bit easier to re-write this code to only free things which
> we know have been allocated successfully.

icssm maintainers - please review

Re: [PATCH net-next] net: ti: icssm-prueth: unwind cleanly in probe()

[Parvathi Pudi]

Hi,

> On Thu, 18 Sep 2025 12:48:26 +0300 Dan Carpenter wrote:
>> This error handling triggers a Smatch warning:
>> 
>>     drivers/net/ethernet/ti/icssm/icssm_prueth.c:1574 icssm_prueth_probe()
>>     warn: 'prueth->pru1' is an error pointer or valid
>> 
>> The warning is harmless because the pru_rproc_put() function has an
>> IS_ERR_OR_NULL() check built in.  However, there is a small bug if
>> syscon_regmap_lookup_by_phandle() fails.  In that case we should call
>> of_node_put() on eth0_node and eth1_node.
>> 
>> It's a little bit easier to re-write this code to only free things which
>> we know have been allocated successfully.
> 
> icssm maintainers - please review

Yes you are correct. This got missed somehow sorry about that.

Now the error return is gracefully exiting by freeing the resources.

Reviewed-by: Parvathi Pudi <parvathi@couthit.com>


Thanks and Regards,
Parvathi.

Re: [PATCH net-next] net: ti: icssm-prueth: unwind cleanly in probe()

[patchwork-bot+netdevbpf]

Hello:

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

On Thu, 18 Sep 2025 12:48:26 +0300 you wrote:
> This error handling triggers a Smatch warning:
> 
>     drivers/net/ethernet/ti/icssm/icssm_prueth.c:1574 icssm_prueth_probe()
>     warn: 'prueth->pru1' is an error pointer or valid
> 
> The warning is harmless because the pru_rproc_put() function has an
> IS_ERR_OR_NULL() check built in.  However, there is a small bug if
> syscon_regmap_lookup_by_phandle() fails.  In that case we should call
> of_node_put() on eth0_node and eth1_node.
> 
> [...]

Here is the summary with links:
  - [net-next] net: ti: icssm-prueth: unwind cleanly in probe()
    https://git.kernel.org/netdev/net-next/c/5fc7fa743dbf

You are awesome, thank you!
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