linux-kernel - Re: [BUG] general protection fault in sock_map_link_update_prog

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <87ldvi3gnq.fsf@cloudflare.com>
Date: Fri, 10 Jan 2025 15:08:41 +0100
From: Jakub Sitnicki <jakub@...udflare.com>
To: Ruan Bonan <bonan.ruan@...us.edu>, Cong Wang <xiyou.wangcong@...il.com>
Cc: "john.fastabend@...il.com" <john.fastabend@...il.com>,
  "davem@...emloft.net" <davem@...emloft.net>,  "edumazet@...gle.com"
 <edumazet@...gle.com>,  "kuba@...nel.org" <kuba@...nel.org>,
  "pabeni@...hat.com" <pabeni@...hat.com>,  "netdev@...r.kernel.org"
 <netdev@...r.kernel.org>,  "bpf@...r.kernel.org" <bpf@...r.kernel.org>,
  "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
  "syzkaller@...glegroups.com" <syzkaller@...glegroups.com>
Subject: Re: [BUG] general protection fault in sock_map_link_update_prog -
 Reproducible with Syzkaller

On Wed, Oct 23, 2024 at 02:51 PM +02, Jakub Sitnicki wrote:
> On Tue, Oct 22, 2024 at 02:36 AM GMT, Ruan Bonan wrote:
>> I used Syzkaller and found that there is KASAN: null-ptr-deref (general protection fault in
>> sock_map_link_update_prog) in net/core/sock_map.c in v6.12.0-rc2, which also causes a KASAN:
>> slab-use-after-free at the same time. It looks like a concurrency bug in the
>> BPF related subsystems. The
>> reproducer is available, and I have reproduced this bug with it
>> manually. Currently I can only reproduce this
>> bug with root privilege.
>>
>> The detailed reports, config file, and reproducer program are attached in this
>> e-mail. If you need further
>> details, please let me know.
>
> Thanks for the report. I was also able to reproduce the KASAN splat with
> the attached repro locally and will investigate futher.

For the record, Cong fixed this bug in commit 740be3b9a6d7 ("sock_map:
fix a NULL pointer dereference in sock_map_link_update_prog()") [1].

[1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=740be3b9a6d73336f8c7d540842d0831dc7a808b