Re: [PATCH net 1/1] udp: diag: bound bucket lock hold time

[Jakub Kicinski]

On Sat, 5 Sep 2026 23:49:05 +0800 zihan xi wrote:
> > When an active netlink dump for UDP sockets finishes, inet_diag_dump_done()
> > invokes udp_diag_dump_done(). This function drops its module reference using
> > module_put(THIS_MODULE) as its final step.
> >
> > If this was the last reference, a concurrent rmmod udp_diag operation can
> > proceed and unmap the module's text segment before the thread executing
> > udp_diag_dump_done() executes its return instruction to return to inet_diag.
> >
> > Could this result in a kernel panic due to the CPU attempting to execute
> > unmapped memory?  
> 
> Yes.  If that module_put() drops the last reference, rmmod can unmap
> udp_diag while dump_done() is still returning to inet_diag.
> 
> I will keep the extra module_get() in udp_diag_dump(), and move the
> matching module_put() into inet_diag_dump_done() so it runs after the
> callback has returned.
> 
> v2 incoming.

FTR your patch also looks atrociously ugly.
If you send v2 please make it better.