On 6/11/19 3:08 AM, Gen Zhang wrote:
On Tue, Jun 11, 2019 at 10:54:15AM +0100, Marc Zyngier wrote:
Hi Gen,

No idea why I'm being cc'd on this but hey... ;-)
I copied email address ftom thid commit:-)
https://github.com/torvalds/linux/commit/832ad0e3da4510fd17f98804abe512ea9a747035#diff-f2a24befc247191f4b81af93e9336785

On 11/06/2019 10:37, Gen Zhang wrote:
On Thu, May 30, 2019 at 11:39:49AM +0800, Gen Zhang wrote:
In knav_pool_create(), 'pool->name' is allocated by kstrndup(). It
returns NULL when fails. So 'pool->name' should be checked. And free
'pool' when error.

Signed-off-by: Gen Zhang <blackgod016...@gmail.com>
---
diff --git a/drivers/soc/ti/knav_qmss_queue.c b/drivers/soc/ti/knav_qmss_queue.c
index 8b41837..0f8cb28 100644
--- a/drivers/soc/ti/knav_qmss_queue.c
+++ b/drivers/soc/ti/knav_qmss_queue.c
@@ -814,6 +814,12 @@ void *knav_pool_create(const char *name,
        }
pool->name = kstrndup(name, KNAV_NAME_SIZE - 1, GFP_KERNEL);
+       if (!pool->name) {
+               dev_err(kdev->dev, "failed to duplicate for pool(%s)\n",
+                       name);

There is no need to output anything, the kernel will be loud enough if
you run out of memory.
Thanks for your comments.

+               ret = -ENOMEM;
+               goto err_name;
+       }
        pool->kdev = kdev;
        pool->dev = kdev->dev;
@@ -864,6 +870,7 @@ void *knav_pool_create(const char *name,
        mutex_unlock(&knav_dev_lock);
  err:
        kfree(pool->name);
+err_name:

kfree(NULL) is perfectly valid, there is no need to create a second
label. Just branch to the existing error label.
Sure, better not to add redundant codes.

        devm_kfree(kdev->dev, pool);
        return ERR_PTR(ret);
  }
Can anyone look into this patch?

Thanks
Gen


The real question is whether this is actually an error at all.
pool->name doesn't seem to be used for anything but debug information,
and the printing code can perfectly accommodate a NULL pointer.
That sounds reasonable. This patch just fixes a *theoretical* bug.

Not even theoretical bug.

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