Re: [PATCH net-next] net: tipc: avoid possible garbage value

From: Dan Carpenter
Date: Sat Sep 14 2024 - 06:05:44 EST


On Sat, Sep 14, 2024 at 10:42:44AM +0100, Simon Horman wrote:
> On Thu, Sep 12, 2024 at 07:01:20PM +0800, Su Hui wrote:
> > Clang static checker (scan-build) warning:
> > net/tipc/bcast.c:305:4:
> > The expression is an uninitialized value. The computed value will also
> > be garbage [core.uninitialized.Assign]
> > 305 | (*cong_link_cnt)++;
> > | ^~~~~~~~~~~~~~~~~~
> >
> > tipc_rcast_xmit() will increase cong_link_cnt's value, but cong_link_cnt
> > is uninitialized. Although it won't really cause a problem, it's better
> > to fix it.
> >
> > Fixes: dca4a17d24ee ("tipc: fix potential hanging after b/rcast changing")
> > Signed-off-by: Su Hui <suhui@xxxxxxxxxxxx>
>
> Hi Su Hui,
>
> This looks like a bug fix. If so it should be targeted at net rather than
> net-next. If not, the Fixes tag should be dropped, and the commit can be
> referenced in the patch description with some other text around:
>


It's one of those borderline things. As the commit message says it doesn't
really cause a problem because cong_link_cnt is never used. I guess if you had
UBSan turned on it would generate a runtime warning. Still it also doesn't seem
intentional so I would probably count it as a bugfix and target net like you
suggest.

regards,
dan carpenter