Re: [syzbot] KASAN: use-after-free Read in rdma_close

[asmadeus]

Leon Romanovsky wrote on Wed, Sep 28, 2022 at 01:07:23PM +0300:
> The bug is in commit 3ff51294a055 ("9p: p9_client_create: use p9_client_destroy on failure").

Thanks for looking

> It is wrong to call to p9_client_destroy() if clnt->trans_mod->create fails.

hmm that's a bit broad :)

But I agree I did get that wrong: trans_mod->close() wasn't called if
create failed.
We do want the idr_for_each_entry() that is in p9_client_destroy so
rather than revert the commit (fix a bug, create a new one..) I'd rather
split it out in an internal function that takes a 'bool close' or
something to not duplicate the rest.
(Bit of a nitpick, sure)

I'll send a patch and credit you in Reported-by unless you don't want
to.

-- 
Dominique