Re: [PATCH net 1/3] net: hns3: fix a use of uninitialized variable problem

[Simon Horman <horms@kernel.org>]

On Wed, Apr 02, 2025 at 08:09:59PM +0800, Jijie Shao wrote:
> From: Yonglong Liu <liuyonglong@huawei.com>
> 
> In hclge_add_fd_entry(), if the flow type is FLOW_EXT, and the data of
> m_ext is all zero, then some members of the local variable "info" are
> not initialized.

Hi,

I am assuming that this occurs when hclge_fd_check_spec() returns early
like this:

        if (!(fs->flow_type & FLOW_EXT) || hclge_fd_is_user_def_all_masked(fs))
                return 0;

But if so, should the description be "flow type is not FLOW_EXT, ..."
(note the "not")? Or perhaps more clearly refer to the FLOW_EXT bit
not being set?

Also, I think it would be worth mentioning hclge_fd_check_spec()
in the patch description, perhaps something like this.

  In hclge_add_fd_entry(), if  hclge_fd_check_spec() returns early
  because the FLOW_EXT bit is not set in the flow type, and ...

Also, does this manifest in a user-visible problem? If so, I think
it would be good to describe it in the patch description.

If not, I think it would be good to mention how the problem was found.
E.g.: "flagged by static analysis" (and mention the tool if it is publicly
Available. Or, "found by inspection".

> 
> Fixes: 67b0e1428e2f ("net: hns3: add support for user-def data of flow director")
> Signed-off-by: Yonglong Liu <liuyonglong@huawei.com>
> Signed-off-by: Jijie Shao <shaojijie@huawei.com>

...