From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-172.mta0.migadu.com (out-172.mta0.migadu.com [91.218.175.172]) (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 CB5CA290F for ; Wed, 19 Mar 2025 23:36:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742427389; cv=none; b=dptRV0qzdLrCFutNmDXnV/konDQcUr4OnuUk96Ica3QRvsGOW0FHoK9y1m6JH7Lv/xHeqULZewAxFB55MOmOhQbUXSDu5a3K7Upbmex7IbU1QClILmmW3NpKsqTnPHwcdXIzcF0Cqo/0RzYDZ+7y2GMVxUYw6R9BFsX/FW31O1Y= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742427389; c=relaxed/simple; bh=YaRk1s+zKGq0iW53na4lPbKXthAEJqUr5Yf1QKrfQcg=; h=MIME-Version:Date:Content-Type:From:Message-ID:Subject:To:Cc: In-Reply-To:References; b=oerwYUnLQKPRgJ/fIyI6V2AOMq74BsRwOxdzW2sgu+ZwK8OPMeZkv3I+zIxkdJk+1NA1RIJ3PDj8n7fsJ/qpoIy9alm4H7KVUpQra/+neOhpGT00Uk3ZIw7hhyXePnqWgeFYd643iAqx+bxhLf+hi1hg3U0joom2pkCwhUFElpc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=QnBImN/V; arc=none smtp.client-ip=91.218.175.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="QnBImN/V" Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1742427375; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=844+bFvi6TAU7lUIUgTQSz2iWfzhmszHPEf60+qFp+8=; b=QnBImN/VO449dDkv3U3QRL7hRSidSmJ8OHba+RK799rWcGmbaMKw2XD/9Oj6KYDCfc4YQr FnBO9EhNIaUm63vbjR1/lAtuuh/t3yG6wgq52jwVX+5KSaGysf8LdyzFi6ERlpxo+HotTe v5LXpOst8ccObU+5LSs8LqvdmGB6Fvg= Date: Wed, 19 Mar 2025 23:36:13 +0000 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: "Jiayuan Chen" Message-ID: <48068a86ea99dffe1e7849fb544eac1746364afb@linux.dev> TLS-Required: No Subject: Re: [PATCH bpf-next v3 1/3] bpf, sockmap: avoid using sk_socket after free when sending To: "Cong Wang" Cc: john.fastabend@gmail.com, jakub@cloudflare.com, 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, martin.lau@linux.dev, song@kernel.org, yonghong.song@linux.dev, kpsingh@kernel.org, sdf@fomichev.me, haoluo@google.com, jolsa@kernel.org, shuah@kernel.org, mhal@rbox.co, sgarzare@redhat.com, netdev@vger.kernel.org, bpf@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org In-Reply-To: References: <20250317092257.68760-1-jiayuan.chen@linux.dev> <20250317092257.68760-2-jiayuan.chen@linux.dev> X-Migadu-Flow: FLOW_OUT 2025/3/20 07:02, "Cong Wang" wrote: >=20 >=20On Mon, Mar 17, 2025 at 05:22:54PM +0800, Jiayuan Chen wrote: >=20 >=20>=20 >=20> The sk->sk_socket is not locked or referenced, and during the call = to > >=20 >=20 > Hm? We should have a reference in socket map, whether directly or >=20 >=20indirectly, right? When we add a socket to a socket map, we do call >=20 >=20sock_map_psock_get_checked() to obtain a reference. >=20 Yes,=20but we remove psock from sockmap when sock_map_close() was called ''' sock_map_close lock_sock(sk); rcu_read_lock(); psock =3D sk_psock(sk); // here we remove psock and the reference of psock become 0 sock_map_remove_links(sk, psock) psock =3D sk_psock_get(sk); if (unlikely(!psock)) goto no_psock; <=3D=3D=3D jmp to no_psock rcu_read_unlock(); release_sock(sk); cancel_delayed_work_sync(&psock->work); <=3D=3D no chance to run = cancel ''' So I think we should hold the psock when backlog running Thanks,