Re: [PATCH] media: vidtv: fix uninitialized args.buf_sz passed by value

[Thomas Weißschuh]

Hi Yihan Ding,

On Fri, Feb 20, 2026 at 09:39:45PM +0800, Ding Yihan wrote:
> While looking into this exact same syzbot report, I noticed that 
> `vidtv_ts_pcr_write_into()` in the same file also suffers from the
>  exact same pass-by-value anti-pattern (passing `struct pcr_write_args` by value). 

Good catch.
 
> Since `pcr_write_args` also contains implicit padding, it remains a potential trigger
>  for identical KMSAN uninit-value warnings during fuzzing in the future.

The fact that the report is about implicit padding is valuable information.
It should be part of the commit message.

> Also, regarding Thomas's concern about modifying shared data: passing the struct 
> as a `const pointer` (e.g., `const struct null_packet_write_args *`) 
> would perfectly guarantee that the state remains read-only.

Agreed.

> Thomas, would it be worth submitting a separate patch now to fix
> `vidtv_ts_pcr_write_into()` to prevent future KMSAN errors? Or would you
> prefer this to be addressed together in Abd-Alrhman's v2?

Doing it together sounds better. This is not urgent anyways in my opinion.
But on the other hand I am just a random guy whose commit got wrongly blamed
in the original Fixes tag and I don't know anything about this subsystem.


Thomas