2023-07-14 10:42:39

by Wang Ming

Subject: [PATCH net v3] 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.

Fixes: eee326fd8334 ("net: thunderx: bgx: Use standard firmware node infrastructure.")
Signed-off-by: Wang Ming <[email protected]>
---
drivers/net/ethernet/cavium/thunder/thunder_bgx.c | 15 +++++++++------
1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/drivers/net/ethernet/cavium/thunder/thunder_bgx.c b/drivers/net/ethernet/cavium/thunder/thunder_bgx.c
index a317feb8decb..f8a8b2ab72aa 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
--
2.25.1

2023-07-18 09:17:49

by Paolo Abeni

Subject: Re: [PATCH net v3] net: thunder: bgx: Fix resource leaks in device_for_each_child_node() loops

On Fri, 2023-07-14 at 15:06 +0200, Markus Elfring 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.
>
> Are imperative change descriptions still preferred?

Yes. The commit message should be re-phrased.

More importantly, it looks like the relevant reference is already
released by of_node_put() and the additional fwnode_handle_put() will
cause a reference underflow.

This patch does not look correct to me.

Cheers,

Paolo