[PATCH] nvme: fix potential memory leaks in nvme_cdev_add

[Javier González]

On 21.05.2021 15:32, Guoqing Jiang wrote:
>We need to call put_device if cdev_device_add failed, otherwise
>kmemleak has below report.
>
>[<0000000024c71758>] kmem_cache_alloc_trace+0x233/0x480
>[<00000000ad2813ed>] device_add+0x7ff/0xe10
>[<0000000035bc54c4>] cdev_device_add+0x72/0xa0
>[<000000006c9aa1e8>] nvme_cdev_add+0xa9/0xf0 [nvme_core]
>[<000000003c4d492d>] nvme_mpath_set_live+0x251/0x290 [nvme_core]
>[<00000000889a58da>] nvme_mpath_add_disk+0x268/0x320 [nvme_core]
>[<00000000192e7161>] nvme_alloc_ns+0x669/0xac0 [nvme_core]
>[<000000007a1a6041>] nvme_validate_or_alloc_ns+0x156/0x280 [nvme_core]
>[<000000003a763c35>] nvme_scan_work+0x221/0x3c0 [nvme_core]
>[<000000009ff10706>] process_one_work+0x5cf/0xb10
>[<000000000644ee25>] worker_thread+0x7a/0x680
>[<00000000285ebd2f>] kthread+0x1c6/0x210
>[<00000000e297c6ea>] ret_from_fork+0x22/0x30
>
>Fixes: 2637baed7801 ("nvme: introduce generic per-namespace chardev")
>Signed-off-by: Guoqing Jiang <jiangguoqing at kylinos.cn>
>---
> drivers/nvme/host/core.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
>diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
>index 522c9b229f80..2e8da13c842c 100644
>--- a/drivers/nvme/host/core.c
>+++ b/drivers/nvme/host/core.c
>@@ -3485,8 +3485,10 @@ int nvme_cdev_add(struct cdev *cdev, struct device *cdev_device,
> 	cdev_init(cdev, fops);
> 	cdev->owner = owner;
> 	ret = cdev_device_add(cdev, cdev_device);
>-	if (ret)
>+	if (ret) {
>+		put_device(cdev_device);
> 		ida_simple_remove(&nvme_ns_chr_minor_ida, minor);
>+	}
> 	return ret;
> }
>
>-- 
>2.25.1
>

Looks good.

Reviewed-by: Javier González <javier.gonz at samsung.com>