From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailtransmit05.runbox.com (mailtransmit05.runbox.com [185.226.149.38]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1570022576C; Mon, 10 Mar 2025 13:08:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.226.149.38 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741612128; cv=none; b=hIirzFdTdKnW4nESTe8u1fqLr0RU+fCyIW/cEM3QedI+9iiqKwXG6gLVwG2JyM2EICBM8MBhC4esv0Fm9LyD+y8xCv3l3S6ty+wN5FFnjZ2wmDkL2bDZ/eovdXAybur8KpstUjrOtPNi2UFymHMcWO5YQyY31I1li4sB10E06aU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741612128; c=relaxed/simple; bh=rdAP5tZXO/e6X0g9/aj7v6Q8fYYTM/HQGTEow6hWTxU=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=CF5/1JXXEQXRdxOIoDLkEDIa4pMPxBP94/vvqP+nEcDc+Qzci4/+nSrMkDj0xcUrNTqkhHmkSOOpojhvcHcqouT5fxODaRzCw6SQtYRY8zgdRIrB2w2MPReqFAHv43omfKOw81wD3zKRexB6HfF87RhusUxdk/rrUGNj+d5yH0Q= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=rbox.co; spf=pass smtp.mailfrom=rbox.co; dkim=pass (2048-bit key) header.d=rbox.co header.i=@rbox.co header.b=A8BFc6kb; arc=none smtp.client-ip=185.226.149.38 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=rbox.co Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=rbox.co Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=rbox.co header.i=@rbox.co header.b="A8BFc6kb" Received: from mailtransmit02.runbox ([10.9.9.162] helo=aibo.runbox.com) by mailtransmit05.runbox.com with esmtps (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (Exim 4.93) (envelope-from ) id 1trcrp-00Brbe-7O; Mon, 10 Mar 2025 14:08:25 +0100 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=rbox.co; s=selector1; h=Content-Transfer-Encoding:Content-Type:In-Reply-To:From: References:Cc:To:Subject:MIME-Version:Date:Message-ID; bh=YMtG22Pqun0Tp+q9j4j91l8TFa4W5ET+k4wRnt7+fP0=; b=A8BFc6kbFm87pNoML1HwqDmRTf UJA/GzevYwKdN5F5BZrgi//pgOyudJoiTj1cK1jqvTlnhZursG3xtzsBooyMMx4vLOx+Py6kxhz8u hIEVjCM4oc8/5KNIerC9JWvKACQGvBa3WFWLxq6inZH8tyNEnNemy3BsVbvmoAWRn+/snlLvSHaXk ddO8bi7iUrcF5CFLUzM58GA01OsGXH138lYeRHo1EjItfLMyknx62msIBc85WDunVEuay4pTlM87c oHaOor4nkaHnadScKgfH3p4cxyNGqYOaGlUCpKQVr2CTHSgJL4J7b442qLYS5+VhMNWyP9iroaqxJ 2zf7qkeA==; Received: from [10.9.9.74] (helo=submission03.runbox) by mailtransmit02.runbox with esmtp (Exim 4.86_2) (envelope-from ) id 1trcrc-0006oZ-M9; Mon, 10 Mar 2025 14:08:13 +0100 Received: by submission03.runbox with esmtpsa [Authenticated ID (604044)] (TLS1.2:ECDHE_SECP256R1__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim 4.93) id 1trcrZ-007B3j-Vc; Mon, 10 Mar 2025 14:08:10 +0100 Message-ID: Date: Mon, 10 Mar 2025 14:08:07 +0100 Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH bpf-next v2 1/3] bpf, sockmap: avoid using sk_socket after free To: Jiayuan Chen , xiyou.wangcong@gmail.com, john.fastabend@gmail.com, jakub@cloudflare.com, martin.lau@linux.dev Cc: davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, horms@kernel.org, andrii@kernel.org, eddyz87@gmail.com, mykolal@fb.com, ast@kernel.org, daniel@iogearbox.net, song@kernel.org, yonghong.song@linux.dev, kpsingh@kernel.org, sdf@fomichev.me, haoluo@google.com, jolsa@kernel.org, shuah@kernel.org, sgarzare@redhat.com, netdev@vger.kernel.org, bpf@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, mrpre@163.com, cong.wang@bytedance.com, syzbot+dd90a702f518e0eac072@syzkaller.appspotmail.com References: <20250228055106.58071-1-jiayuan.chen@linux.dev> <20250228055106.58071-2-jiayuan.chen@linux.dev> <78ee737400721758fa67b4f285e8ba61dc6b893b@linux.dev> Content-Language: pl-PL, en-GB From: Michal Luczaj In-Reply-To: <78ee737400721758fa67b4f285e8ba61dc6b893b@linux.dev> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 3/10/25 12:36, Jiayuan Chen wrote: > March 7, 2025 at 5:45 PM, "Michal Luczaj" wrote: > ... >> BTW, lockdep (CONFIG_LOCKDEP=y) complains about calling AF_UNIX's >> read_skb() under RCU read lock. >> > My environment also has LOCKDEP enabled, but I didn't see similar > warnings. > Moreover, RCU assertions are typically written as: > > WARN_ON_ONCE(!rcu_read_lock_held()) > > And when LOCKDEP is not enabled, rcu_read_lock_held() defaults to > returning 1. So, it's unlikely to trigger a warning due to an RCU lock > being held. > > Could you provide more of the call stack? Sure, bpf-next with this series applied, test_progs -t sockmap_basic: ============================= [ BUG: Invalid wait context ] 6.14.0-rc3+ #111 Tainted: G OE ----------------------------- test_progs/37755 is trying to lock: ffff88810d9bc3c0 (&u->iolock){+.+.}-{4:4}, at: unix_stream_read_skb+0x30/0x120 other info that might help us debug this: context-{5:5} 1 lock held by test_progs/37755: #0: ffffffff833700e0 (rcu_read_lock){....}-{1:3}, at: sk_psock_verdict_data_ready+0x3e/0x2a0 stack backtrace: CPU: 13 UID: 0 PID: 37755 Comm: test_progs Tainted: G OE 6.14.0-rc3+ #111 Tainted: [O]=OOT_MODULE, [E]=UNSIGNED_MODULE Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Arch Linux 1.16.3-1-1 04/01/2014 Call Trace: dump_stack_lvl+0x68/0x90 lock_acquire+0xcf/0x2e0 __mutex_lock+0x9c/0xcc0 unix_stream_read_skb+0x30/0x120 sk_psock_verdict_data_ready+0x8d/0x2a0 unix_stream_sendmsg+0x232/0x640 __sys_sendto+0x1cd/0x1e0 __x64_sys_sendto+0x20/0x30 do_syscall_64+0x93/0x180 entry_SYSCALL_64_after_hwframe+0x76/0x7e