From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (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 9CD38173 for ; Sun, 20 Aug 2023 00:10:27 +0000 (UTC) Received: from mail-pg1-x533.google.com (mail-pg1-x533.google.com [IPv6:2607:f8b0:4864:20::533]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 30B6E83181; Sat, 19 Aug 2023 13:20:46 -0700 (PDT) Received: by mail-pg1-x533.google.com with SMTP id 41be03b00d2f7-565e387000fso1444266a12.2; Sat, 19 Aug 2023 13:20:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1692476445; x=1693081245; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=lV81kcD9vzqzEmQhBftWFfOiwm9XqB0HTp7lUGKFHuQ=; b=hZnuQQISbxby46D/lP+4Ei7dHYxRBhQic/eRN5kTkc9V6JZF29YKmpDTdaqO90yJJA EYfSIcO/LOPLEq/LryJpbmRKk1pANHtcF52CDEGEEzTwQ7V1I+1xp/sM81IlwNVFBwVz dafywa9Yd7Sp3koKHAQruHj7YLmXlH6EoyymrHyMCzJi8/kpCGSvjGKSXDI2uuSzKs9n c7/OAxWLuWY7G2UqXpJxyy/13i6rPI8Yfr9kF/rPgMiKr7pgPHC2lnGQaWD4xdPKZR4A ICUXRCijQfOfMnCyH6RFSn18f6fVgwXQoi0ABLTU/y1Oa+8xIxYyjKE1hBHYweAiN/Sa U5aA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1692476445; x=1693081245; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=lV81kcD9vzqzEmQhBftWFfOiwm9XqB0HTp7lUGKFHuQ=; b=dxjWc0Q84yk/9pmLok2fna0f6Sm/S2CJBccZSZKOPN67jr2LP0SGdAJVEYehOzrhq5 3PO3PG2vjPZhF2poph1QGtAI0peW0B931f/JkXfhspNQ6D/Vl+PWeyPxuQuF/d29byEl vWqo0wmkd9rCIhZm83W6DPZ6+Ku0ezTLRpLPLV6lh6JIY7Ob7+rQmwOUWjC96IOsxBco 8/jG5QXj0xZR1rDmVZ7wlX+GOLxj3Ux0QVAXCLcbYEo+TSIu/uY3/7dz0eF7NCf2uUet /CwkW3M6B9opq6zg6K2cJbm3++w8+0ApFHlmPEvEQW8vATIHeJ//T9IMT5G7VR8GMYN+ y+LA== X-Gm-Message-State: AOJu0Yz5pqT9mSK2uqXfhZtS0EdqgaR8VTDh27RsgLZrRNoHlfCVKN93 T82CskxkeHIhscWIU+Dk7uc= X-Google-Smtp-Source: AGHT+IG7kGC5rBg79iPGG+ZJMpC1r0dYR+YIh6HwAHWdpK/oApVWvQK46aSWG7nYxgm3nf66BzKAUA== X-Received: by 2002:a17:90a:4dc6:b0:26d:2fe5:ff2a with SMTP id r6-20020a17090a4dc600b0026d2fe5ff2amr2356147pjl.29.1692476445535; Sat, 19 Aug 2023 13:20:45 -0700 (PDT) Received: from DESKTOP-7B1REV8.localdomain ([2001:569:5755:c600:f49d:4018:e752:1f22]) by smtp.gmail.com with ESMTPSA id 5-20020a17090a018500b0026b26181ac9sm5695245pjc.14.2023.08.19.13.20.44 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 19 Aug 2023 13:20:44 -0700 (PDT) From: Qingjie Xing To: edumazet@google.com Cc: davem@davemloft.net, dhowells@redhat.com, fw@strlen.de, johannes@sipsolutions.net, keescook@chromium.org, kuba@kernel.org, kuniyu@amazon.com, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, pabeni@redhat.com, pctammela@mojatatu.com, xqjcool@gmail.com Subject: [PATCH] netlink: Fix the netlink socket malfunction due to concurrency Date: Sat, 19 Aug 2023 13:17:16 -0700 Message-Id: <20230819201716.2430-1-xqjcool@gmail.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: References: Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_FROM, RCVD_IN_DNSWL_BLOCKED,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net This piece of code has been present since the Linux code v2.6.12 was incorporated into Git management. I believe this modification could potentially address the concurrent issue we've been discussing. In netlink_rcv_wake(), as described in [2], the socket's receive queue is empty, indicated by sk_rmem_alloc being 0. At this point, concurrent netlink_attachskb() calls netlink_overrun(). In this critical state, the sk_rmem_alloc of the socket will not instantly transition from 0 to a value greater than sk_rcvbuf.