Messages in this thread Patch in this message | | | From | Zhu Wang <> | Subject | [PATCH -next] scsi: core: fix double free in raid_component_add() | Date | Sat, 19 Aug 2023 08:03:45 +0000 |
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Previous commit 04b5b5cb0136 ("scsi: core: Fix possible memory leak if device_add() fails") introduced a double free when device_add() failed. When device_add() failed, the put_device(&rc->dev) is called, which will call raid_component_release(), and this function will call put_device(rc->dev.parent) and kfree(rc), but in the error path of raid_component_release() above two functions are called again, so 'rc' are freed twice.
We do not just revert the patch, since the memory allocated by dev_set_name() is not released in the error path, it should be released through calling put_device(&rc->dev) which will call kobject_cleanup(), and the device name will be released in it. Though the commit 04b5b5cb0136 ("scsi: core: Fix possible memory leak if device_add() fails") fixed the memory leak, it didn't consider the double free problem. We removed put_device(rc->dev.parent) and kfree(rc) in the error path, and we moved put_device(&rc->dev) after rd->component-count--, since after put_device(&rc->dev) is called, 'rc' is freed, so list_del(&rc->node) cannot be called again.
Fixes: 04b5b5cb0136 ("scsi: core: Fix possible memory leak if device_add() fails") Signed-off-by: Zhu Wang <wangzhu9@huawei.com> --- drivers/scsi/raid_class.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/drivers/scsi/raid_class.c b/drivers/scsi/raid_class.c index 711252e52d8e..86ed1f66d749 100644 --- a/drivers/scsi/raid_class.c +++ b/drivers/scsi/raid_class.c @@ -248,11 +248,9 @@ int raid_component_add(struct raid_template *r,struct device *raid_dev, return 0; err_out: - put_device(&rc->dev); list_del(&rc->node); rd->component_count--; - put_device(component_dev); - kfree(rc); + put_device(&rc->dev); return err; } EXPORT_SYMBOL(raid_component_add); -- 2.34.1
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