[PATCH v5] [ARM] fix reference leak in locomo_init_one_child()

From: Ma Ke
Date: Thu Jan 16 2025 - 02:14:23 EST


Once device_register() failed, we should call put_device() to
decrement reference count for cleanup. Or it could cause memory leak.

As comment of device_register() says, 'NOTE: _Never_ directly free
@dev after calling this function, even if it returned an error! Always
use put_device() to give up the reference initialized in this function
instead.'

Found by code review.

Cc: stable@xxxxxxxxxxxxxxx
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Ma Ke <make24@xxxxxxxxxxx>
---
Changes in v5:
- modified the bug description as suggestions;
Changes in v4:
- deleted the redundant initialization;
Changes in v3:
- modified the patch as suggestions;
Changes in v2:
- modified the patch as suggestions.
---
arch/arm/common/locomo.c | 13 +++++--------
1 file changed, 5 insertions(+), 8 deletions(-)

diff --git a/arch/arm/common/locomo.c b/arch/arm/common/locomo.c
index cb6ef449b987..45106066a17f 100644
--- a/arch/arm/common/locomo.c
+++ b/arch/arm/common/locomo.c
@@ -223,10 +223,8 @@ locomo_init_one_child(struct locomo *lchip, struct locomo_dev_info *info)
int ret;

dev = kzalloc(sizeof(struct locomo_dev), GFP_KERNEL);
- if (!dev) {
- ret = -ENOMEM;
- goto out;
- }
+ if (!dev)
+ return -ENOMEM;

/*
* If the parent device has a DMA mask associated with it,
@@ -254,10 +252,9 @@ locomo_init_one_child(struct locomo *lchip, struct locomo_dev_info *info)
NO_IRQ : lchip->irq_base + info->irq[0];

ret = device_register(&dev->dev);
- if (ret) {
- out:
- kfree(dev);
- }
+ if (ret)
+ put_device(&dev->dev);
+
return ret;
}

--
2.25.1