Received-SPF: pass (google.com: domain of linux-crypto+bounces-1678-linux.lists.archive=gmail.com@vger.kernel.org designates 139.178.88.99 as permitted sender) client-ip=139.178.88.99;
Precedence: bulk
MIME-Version: 1.0
From: xingwei lee <xrivendell7@gmail.com>
Date: Fri, 26 Jan 2024 21:11:39 +0800
Message-ID: <CABOYnLx_8_TpFHS-nkrvF5dG_Ev6tgMi1dj_+4sSydM1wmD1XA@mail.gmail.com>
Subject: Re: [syzbot] [crypto?] KMSAN: uninit-value in af_alg_free_sg (2)
To: syzbot+3266db0c26d1fbbe3abb@syzkaller.appspotmail.com
Cc: davem@davemloft.net, herbert@gondor.apana.org.au, 
	linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org, 
	syzkaller-bugs@googlegroups.com
Content-Type: text/plain; charset="UTF-8"

Hello.
This bug is the same bug that is mentioned in
https://lore.kernel.org/all/20231211135949.689204-1-syoshida@redhat.com/.
And I also reproduced it with repro.c in
https://lore.kernel.org/all/CABOYnLxaHBEaSRaEU+kDsHF8a=9AokO1ZUEVtpeT9ddL8giw3A@mail.gmail.com/
also see in https://gist.github.com/xrivendell7/b10745f297bd2d12a2e48155920996d2
and also a simple root cause analysis.

The incorrect logic of unlock_free label can really cause security issue like
KASAN: double-free in af_alg_free_sg
KASAN: slab-use-after-free in af_alg_free_sg
KASAN: slab-use-after-free Read in hash_sock_destruct

and it needs a quick fix.

I hope it helps.

Best regards.
xingwei Lee