[v2 PATCH] net: fec: free fec queue when fec_probe() fails or fec_drv_remove()

[v2 PATCH] net: fec: free fec queue when fec_probe() fails or fec_drv_remove()

[Xiaolei Wang]

commit 59d0f7465644 ("net: fec: init multi queue date structure")
allocates multiple queues, which should be cleaned up when fec_probe()
fails or fec_drv_remove(), otherwise a memory leak will occur.

unreferenced object 0xffffff8010350000 (size 8192):
  comm "kworker/u8:3", pid 39, jiffies 4294893562
  hex dump (first 32 bytes):
    02 00 00 00 00 00 00 00 00 50 06 8a c0 ff ff ff  .........P......
    e0 6f 06 8a c0 ff ff ff 00 50 06 8a c0 ff ff ff  .o.......P......
  backtrace (crc f1b8b79f):
    [<0000000057d2c6ae>] kmemleak_alloc+0x34/0x40
    [<000000003c413e60>] kmalloc_trace+0x2f8/0x460
    [<00000000663f64e6>] fec_probe+0x1364/0x3a04
    [<0000000024d7e427>] platform_probe+0xc4/0x198
    [<00000000293aa124>] really_probe+0x17c/0x4f0
    [<00000000dfd1e0f3>] __driver_probe_device+0x158/0x2c4

Fixes: 59d0f7465644 ("net: fec: init multi queue date structure")
Signed-off-by: Xiaolei Wang <xiaolei.wang@windriver.com>
---
v1 -> v2
 - Add fec_enet_free_queue() in fec_drv_remove()

 drivers/net/ethernet/freescale/fec_main.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c
index a72d8a2eb0b3..775029af6042 100644
--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
@@ -4524,6 +4524,7 @@ fec_probe(struct platform_device *pdev)
 	fec_enet_mii_remove(fep);
 failed_mii_init:
 failed_irq:
+	fec_enet_free_queue(ndev);
 failed_init:
 	fec_ptp_stop(pdev);
 failed_reset:
@@ -4587,6 +4588,7 @@ fec_drv_remove(struct platform_device *pdev)
 	pm_runtime_put_noidle(&pdev->dev);
 	pm_runtime_disable(&pdev->dev);
 
+	fec_enet_free_queue(ndev);
 	free_netdev(ndev);
 }
 
-- 
2.25.1

Re: [v2 PATCH] net: fec: free fec queue when fec_probe() fails or fec_drv_remove()

[Andrew Lunn]

On Thu, May 23, 2024 at 02:29:20PM +0800, Xiaolei Wang wrote:
> commit 59d0f7465644 ("net: fec: init multi queue date structure")
> allocates multiple queues, which should be cleaned up when fec_probe()
> fails or fec_drv_remove(), otherwise a memory leak will occur.
> 
> unreferenced object 0xffffff8010350000 (size 8192):
>   comm "kworker/u8:3", pid 39, jiffies 4294893562
>   hex dump (first 32 bytes):
>     02 00 00 00 00 00 00 00 00 50 06 8a c0 ff ff ff  .........P......
>     e0 6f 06 8a c0 ff ff ff 00 50 06 8a c0 ff ff ff  .o.......P......
>   backtrace (crc f1b8b79f):
>     [<0000000057d2c6ae>] kmemleak_alloc+0x34/0x40
>     [<000000003c413e60>] kmalloc_trace+0x2f8/0x460
>     [<00000000663f64e6>] fec_probe+0x1364/0x3a04
>     [<0000000024d7e427>] platform_probe+0xc4/0x198
>     [<00000000293aa124>] really_probe+0x17c/0x4f0
>     [<00000000dfd1e0f3>] __driver_probe_device+0x158/0x2c4
> 
> Fixes: 59d0f7465644 ("net: fec: init multi queue date structure")
> Signed-off-by: Xiaolei Wang <xiaolei.wang@windriver.com>

Please read what i suggested. It is good to have code which is
symmetric. probe() and remove() should be opposites of each other.
probe() calls fec_enet_init(). So it would be good to have remove()
call fec_enet_deinit() which does the opposite. We then have symmetry.

Is there anything else in fec_enet_init() which needs undoing? A rule
of thumb: If you find a bug, look around, there might be others
nearby. Maybe leaking the queues is not the only problem?

	Andrew

RE: [v2 PATCH] net: fec: free fec queue when fec_probe() fails or fec_drv_remove()

[Wei Fang]

> -----Original Message-----
> From: Xiaolei Wang <xiaolei.wang@windriver.com>
> Sent: 2024年5月23日 14:29
> To: Wei Fang <wei.fang@nxp.com>; andrew@lunn.ch; Shenwei Wang
> <shenwei.wang@nxp.com>; Clark Wang <xiaoning.wang@nxp.com>;
> davem@davemloft.net; edumazet@google.com; kuba@kernel.org;
> pabeni@redhat.com
> Cc: imx@lists.linux.dev; netdev@vger.kernel.org;
> linux-kernel@vger.kernel.org
> Subject: [v2 PATCH] net: fec: free fec queue when fec_probe() fails or
> fec_drv_remove()
> 
> commit 59d0f7465644 ("net: fec: init multi queue date structure")
> allocates multiple queues, which should be cleaned up when fec_probe()
> fails or fec_drv_remove(), otherwise a memory leak will occur.
> 
> unreferenced object 0xffffff8010350000 (size 8192):
>   comm "kworker/u8:3", pid 39, jiffies 4294893562
>   hex dump (first 32 bytes):
>     02 00 00 00 00 00 00 00 00 50 06 8a c0 ff ff ff  .........P......
>     e0 6f 06 8a c0 ff ff ff 00 50 06 8a c0 ff ff ff  .o.......P......
>   backtrace (crc f1b8b79f):
>     [<0000000057d2c6ae>] kmemleak_alloc+0x34/0x40
>     [<000000003c413e60>] kmalloc_trace+0x2f8/0x460
>     [<00000000663f64e6>] fec_probe+0x1364/0x3a04
>     [<0000000024d7e427>] platform_probe+0xc4/0x198
>     [<00000000293aa124>] really_probe+0x17c/0x4f0
>     [<00000000dfd1e0f3>] __driver_probe_device+0x158/0x2c4
> 
> Fixes: 59d0f7465644 ("net: fec: init multi queue date structure")
> Signed-off-by: Xiaolei Wang <xiaolei.wang@windriver.com>
> ---
> v1 -> v2
>  - Add fec_enet_free_queue() in fec_drv_remove()
> 
>  drivers/net/ethernet/freescale/fec_main.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/net/ethernet/freescale/fec_main.c
> b/drivers/net/ethernet/freescale/fec_main.c
> index a72d8a2eb0b3..775029af6042 100644
> --- a/drivers/net/ethernet/freescale/fec_main.c
> +++ b/drivers/net/ethernet/freescale/fec_main.c
> @@ -4524,6 +4524,7 @@ fec_probe(struct platform_device *pdev)
>  	fec_enet_mii_remove(fep);
>  failed_mii_init:
>  failed_irq:
> +	fec_enet_free_queue(ndev);
>  failed_init:
>  	fec_ptp_stop(pdev);
>  failed_reset:
> @@ -4587,6 +4588,7 @@ fec_drv_remove(struct platform_device *pdev)
>  	pm_runtime_put_noidle(&pdev->dev);
>  	pm_runtime_disable(&pdev->dev);
> 
> +	fec_enet_free_queue(ndev);
>  	free_netdev(ndev);
>  }
> 
> --
> 2.25.1

Thanks!
Reviewed-by: Wei Fang <wei.fang@nxp.com>