As the possible failure of the allocation, kzalloc() may return NULL
pointer.
Therefore, it should be better to check the 'sgi' in order to prevent
the dereference of NULL pointer.

Fixes: 23ae3a7877718 ("net: dsa: felix: add stream gate settings for psfpq").
Signed-off-by: Zheng Yongjun <zhengyongjun3@huawei.com>
---
 drivers/net/dsa/ocelot/felix_vsc9959.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/net/dsa/ocelot/felix_vsc9959.c b/drivers/net/dsa/ocelot/felix_vsc9959.c
index 33f0ceae381d..2875b5250856 100644
--- a/drivers/net/dsa/ocelot/felix_vsc9959.c
+++ b/drivers/net/dsa/ocelot/felix_vsc9959.c
@@ -1940,6 +1940,10 @@ static int vsc9959_psfp_filter_add(struct ocelot *ocelot, int port,
 		case FLOW_ACTION_GATE:
 			size = struct_size(sgi, entries, a->gate.num_entries);
 			sgi = kzalloc(size, GFP_KERNEL);
+			if (!sgi) {
+				ret = -ENOMEM;
+				goto err;
+			}
 			vsc9959_psfp_parse_gate(a, sgi);
 			ret = vsc9959_psfp_sgi_table_add(ocelot, sgi);
 			if (ret) {
-- 
2.17.1

Hello,

On Tue, 2022-03-29 at 08:12 +0000, Zheng Yongjun wrote:
> As the possible failure of the allocation, kzalloc() may return NULL
> pointer.
> Therefore, it should be better to check the 'sgi' in order to prevent
> the dereference of NULL pointer.
> 
> Fixes: 23ae3a7877718 ("net: dsa: felix: add stream gate settings for psfpq").

It looks like the fixes tag has been corrupted (trailing 'q'). Would
you mind posting a v2 with that fixed ?

Thanks,

Paolo

Thanks for point out my mistake :)
-----邮件原件-----
发件人: Paolo Abeni [mailto:pabeni@redhat.com] 
发送时间: 2022年3月29日 17:00
收件人: zhengyongjun <zhengyongjun3@huawei.com>; andrew@lunn.ch; vivien.didelot@gmail.com; f.fainelli@gmail.com; davem@davemloft.net; kuba@kernel.org; netdev@vger.kernel.org; linux-kernel@vger.kernel.org
抄送: vladimir.oltean@nxp.com; claudiu.manoil@nxp.com; alexandre.belloni@bootlin.com; UNGLinuxDriver@microchip.com
主题: Re: [PATCH] net: dsa: felix: fix possible NULL pointer dereference

Hello,

On Tue, 2022-03-29 at 08:12 +0000, Zheng Yongjun wrote:
> As the possible failure of the allocation, kzalloc() may return NULL 
> pointer.
> Therefore, it should be better to check the 'sgi' in order to prevent 
> the dereference of NULL pointer.
> 
> Fixes: 23ae3a7877718 ("net: dsa: felix: add stream gate settings for psfpq").

It looks like the fixes tag has been corrupted (trailing 'q'). Would you mind posting a v2 with that fixed ?

Thanks,

Paolo