Re: [syzbot] KASAN: use-after-free Read in rdma_close
From: Leon Romanovsky <leon@kernel.org>
Date: 2022-09-28 10:49:53
Also in:
lkml
From: Leon Romanovsky <leon@kernel.org>
Date: 2022-09-28 10:49:53
Also in:
lkml
On Wed, Sep 28, 2022 at 07:43:38PM +0900, asmadeus@codewreck.org wrote:
Leon Romanovsky wrote on Wed, Sep 28, 2022 at 01:07:23PM +0300:quoted
The bug is in commit 3ff51294a055 ("9p: p9_client_create: use p9_client_destroy on failure").Thanks for lookingquoted
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)
Please do proper unwind without extra variable. Proper unwind means that you will call to symmetrical functions in destroy as you used in create: alloc -> free create -> close e.t.c When you use some global function like you did, there is huge chance to see unwind bugs.
I'll send a patch and credit you in Reported-by unless you don't want to. -- Dominique