Re: [PATCH] USB: serial: opticon: fix UAF in write callback during port removal

[Fan Wu]

> On Mar 11, 2026, at 20:14, Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
> On Tue, Mar 10, 2026 at 05:04:24PM +0000, Fan Wu wrote:
>> On Tue, Mar 10, 2026 at 09:56:48 +0100, Johan Hovold wrote:
>>> How was this potential issue found? Are you using some kind of LLM or
>>> other tool?
>> 
>> Hi Johan,
>> 
>> Thanks for the explanation. You're right — I missed the lifecycle guarantees
>> provided by usb_serial_disconnect(), and since opticon_close() already handles
>> the URB cleanup, this report is a false positive.
>> 
>> I'm currently researching static analysis techniques (CodeQL combined with LLM
>> assistance) for detecting UAF bugs, particularly around cross-entry lifetimes.
>> In this case, the analysis missed the subsystem-level guarantee that close runs
>> before remove.
> 
> As is required, you always have to document this type of thing in the
> changelog text.
> 
> thanks,
> 
> greg k-h

Hi Johan,

Thanks for the reminder. Understood — I'll make sure to explicitly document the 
search method and tool assistance in the changelog for any future patches.

Best regards,
Fan Wu