2023-07-04 14:45:07

by Wang Ming

Subject: [PATCH v1] net:thunder_bgx:Fix resource leaks in device_for_each_child_node() loops

The device_for_each_child_node() loop in
bgx_init_of_phy() function should have
fwnode_handle_put() before break which could
avoid resource leaks.
This patch could fix this bug.

Signed-off-by: Wang Ming <[email protected]>
---
drivers/net/ethernet/cavium/thunder/thunder_bgx.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/cavium/thunder/thunder_bgx.c b/drivers/net/ethernet/cavium/thunder/thunder_bgx.c
index a317feb8d..dad32d36a 100644
--- a/drivers/net/ethernet/cavium/thunder/thunder_bgx.c
+++ b/drivers/net/ethernet/cavium/thunder/thunder_bgx.c
@@ -1478,8 +1478,10 @@ static int bgx_init_of_phy(struct bgx *bgx)
* cannot handle it, so exit the loop.
*/
node = to_of_node(fwn);
- if (!node)
+ if (!node) {
+ fwnode_handle_put(fwn);
break;
+ }

of_get_mac_address(node, bgx->lmac[lmac].mac);

@@ -1503,6 +1505,7 @@ static int bgx_init_of_phy(struct bgx *bgx)
lmac++;
if (lmac == bgx->max_lmac) {
of_node_put(node);
+ fwnode_handle_put(fwn);
break;
}
}
--
2.25.1

2023-07-04 20:42:59

by Simon Horman

Subject: Re: [PATCH v1] net:thunder_bgx:Fix resource leaks in device_for_each_child_node() loops

On Tue, Jul 04, 2023 at 10:14:47PM +0800, Wang Ming wrote:
> The device_for_each_child_node() loop in
> bgx_init_of_phy() function should have
> fwnode_handle_put() before break which could
> avoid resource leaks.
> This patch could fix this bug.

Hi Wang Ming,

If this fixes a bug then it probably warrants a fixes tag.
And it should also probably be targeted at the next tree:

[PATCH net v2] ...

If so, please allow 24h to elapse before posting v2.

Else it should be targeted at the net-next tree,
and posted after net-next reopens after July 10th:

[PATCH net-next v2] ...

Also, looking at git history, I think a more appropriate subject prefix
would be 'net: thunderx: '

[PATCH net v2] net: thunderx: ...

Link: https://www.kernel.org/doc/html/next/process/maintainer-netdev.html

> Signed-off-by: Wang Ming <[email protected]>
> ---
> drivers/net/ethernet/cavium/thunder/thunder_bgx.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/net/ethernet/cavium/thunder/thunder_bgx.c b/drivers/net/ethernet/cavium/thunder/thunder_bgx.c
> index a317feb8d..dad32d36a 100644
> --- a/drivers/net/ethernet/cavium/thunder/thunder_bgx.c
> +++ b/drivers/net/ethernet/cavium/thunder/thunder_bgx.c
> @@ -1478,8 +1478,10 @@ static int bgx_init_of_phy(struct bgx *bgx)
> * cannot handle it, so exit the loop.
> */
> node = to_of_node(fwn);
> - if (!node)
> + if (!node) {
> + fwnode_handle_put(fwn);
> break;
> + }
>
> of_get_mac_address(node, bgx->lmac[lmac].mac);
>
> @@ -1503,6 +1505,7 @@ static int bgx_init_of_phy(struct bgx *bgx)
> lmac++;
> if (lmac == bgx->max_lmac) {
> of_node_put(node);
> + fwnode_handle_put(fwn);
> break;
> }
> }

Should this change also apply to the 'goto defer' case in the same loop?
If so, perhaps a more idiomatic approach of releasing resources
in a ladder of goto labels is appropriate. Something like this (untested!):

diff --git a/drivers/net/ethernet/cavium/thunder/thunder_bgx.c b/drivers/net/ethernet/cavium/thunder/thunder_bgx.c
index a317feb8decb..3091c96134e4 100644
--- a/drivers/net/ethernet/cavium/thunder/thunder_bgx.c
+++ b/drivers/net/ethernet/cavium/thunder/thunder_bgx.c
@@ -1469,6 +1469,7 @@ static int bgx_init_of_phy(struct bgx *bgx)
struct fwnode_handle *fwn;
struct device_node *node = NULL;
u8 lmac = 0;
+ int err = 0;

device_for_each_child_node(&bgx->pdev->dev, fwn) {
struct phy_device *pd;
@@ -1479,7 +1480,7 @@ static int bgx_init_of_phy(struct bgx *bgx)
*/
node = to_of_node(fwn);
if (!node)
- break;
+ goto out_handle_put;

of_get_mac_address(node, bgx->lmac[lmac].mac);

@@ -1501,10 +1502,8 @@ static int bgx_init_of_phy(struct bgx *bgx)
}

lmac++;
- if (lmac == bgx->max_lmac) {
- of_node_put(node);
- break;
- }
+ if (lmac == bgx->max_lmac)
+ goto out_node_put;
}
return 0;

@@ -1519,8 +1518,12 @@ static int bgx_init_of_phy(struct bgx *bgx)
}
lmac--;
}
+ err = -EPROBE_DEFER;
+out_node_put:
of_node_put(node);
- return -EPROBE_DEFER;
+out_handle_put:
+ fwnode_handle_put(fwn);
+ return err;
}

#else

--
pw-bot: changes-requested