[PATCH] HSI: core: Fix return freed object in hsi_new_client

[PATCH] HSI: core: Fix return freed object in hsi_new_client

[Chengfeng Ye]

cl is freed on error of calling device_register, but this
object is return later, which will cause uaf issue. Fix it
by return NULL on error.

Signed-off-by: Chengfeng Ye <cyeaa@connect.ust.hk>
---
 drivers/hsi/hsi_core.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/hsi/hsi_core.c b/drivers/hsi/hsi_core.c
index ec90713564e3..884066109699 100644
--- a/drivers/hsi/hsi_core.c
+++ b/drivers/hsi/hsi_core.c
@@ -102,6 +102,7 @@ struct hsi_client *hsi_new_client(struct hsi_port *port,
 	if (device_register(&cl->device) < 0) {
 		pr_err("hsi: failed to register client: %s\n", info->name);
 		put_device(&cl->device);
+		goto err;
 	}
 
 	return cl;
-- 
2.17.1

回复: [PATCH] HSI: core: Fix return freed object in hsi_new_client

[YE Chengfeng]

Hi, 

We send a patch for this suspected uaf issue. Would you like to have a look at it?

Best regards,
Chengfeng

-----邮件原件-----
发件人: YE Chengfeng 
发送时间: 2021年11月5日 21:45
收件人: sre@kernel.org
抄送: linux-kernel@vger.kernel.org; YE Chengfeng <cyeaa@connect.ust.hk>
主题: [PATCH] HSI: core: Fix return freed object in hsi_new_client

cl is freed on error of calling device_register, but this object is return later, which will cause uaf issue. Fix it by return NULL on error.

Signed-off-by: Chengfeng Ye <cyeaa@connect.ust.hk>
---
 drivers/hsi/hsi_core.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/hsi/hsi_core.c b/drivers/hsi/hsi_core.c index ec90713564e3..884066109699 100644
--- a/drivers/hsi/hsi_core.c
+++ b/drivers/hsi/hsi_core.c
@@ -102,6 +102,7 @@ struct hsi_client *hsi_new_client(struct hsi_port *port,
 	if (device_register(&cl->device) < 0) {
 		pr_err("hsi: failed to register client: %s\n", info->name);
 		put_device(&cl->device);
+		goto err;
 	}
 
 	return cl;
--
2.17.1