From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id DD328C433EF for ; Tue, 1 Mar 2022 04:03:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231261AbiCAEDm (ORCPT ); Mon, 28 Feb 2022 23:03:42 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37534 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230272AbiCAEDk (ORCPT ); Mon, 28 Feb 2022 23:03:40 -0500 Received: from mail-io1-xd35.google.com (mail-io1-xd35.google.com [IPv6:2607:f8b0:4864:20::d35]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6D8604BFDC; Mon, 28 Feb 2022 20:03:00 -0800 (PST) Received: by mail-io1-xd35.google.com with SMTP id w7so17175009ioj.5; Mon, 28 Feb 2022 20:03:00 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=date:from:to:cc:message-id:in-reply-to:references:subject :mime-version:content-transfer-encoding; bh=QbGiC4M7yjcGNMo3K5OFtxH8Uhk9ttEp8MVhuXYPVJw=; b=RS5TgXUTmZdxWOKt9lpX1fSbzxAYg63DwcoVNE25UuVL6u8najpILJVkFwCj4B3Z0i w45wLPscmhSv8x63H1OW5wim5f7OYOa0U2YbTN3bDVxmXHYYLOrV+nnG2GGSoF5lnic1 n9Wp8kZlpXR6Wm8cxHKFI1tHJ/iQuCSmmU/KFAkRWZLfjELvSeBUoxvpPadIvGct9/MN BxDcSknYMAxNPh4XwhsnbM+wVu7uFRoJjg571mk9kaVzzNlcgTfKo190hikzJQhh/IW+ ccULwGj/4K+hSpGdfSPwWasWOGkdqf0dGj8mODn6/561y17RpD1xiy/8uBHH/pmt4WGz jL8Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:message-id:in-reply-to :references:subject:mime-version:content-transfer-encoding; bh=QbGiC4M7yjcGNMo3K5OFtxH8Uhk9ttEp8MVhuXYPVJw=; b=12Tlabq9btazX+Bm5zqnARBh07ldRusul9a5CS3NB0lO2r8a91u+ZJkaPQD22z4zGH PRnl5FTq1OVUevO3vNlucH3erXHuOY1gWxn1Vjrh7TxFAuAVJAPgQ03NmM5TL+vbV/Wp 6eyW71Ff7wOJ+RqAwa/KOS2WwzDL9uSzEQj7JV8ioPCTfHRpujne+YHbWEwbmBnayrtE Vxl8vsr3ljdNWfKkfpOPKsU2WRj0LRpTiRHC2H+l3I5fuF1BUKYgLkp0pEwUOypPcWnH iLtZmWmgAczNSSpJJiLns/EdlRhqfq9QXG/kXlVpwtVdad4lKxigjtnmui2DWyFVs17o OA/A== X-Gm-Message-State: AOAM532M+5IQhbIKz3su2sMaf0q+LNHLPoplwBQMDT/OnXI2YsV4hIZQ +DcIYVvxmewywMGt/nShUXA= X-Google-Smtp-Source: ABdhPJywKwvEilzemENObt86ACBcCDnzan6rjFida8BY+GPH51BGw+1D/vzcYN1WScKxIsckJdR0Jw== X-Received: by 2002:a02:a1c7:0:b0:314:cc99:3c4f with SMTP id o7-20020a02a1c7000000b00314cc993c4fmr19285817jah.53.1646107379809; Mon, 28 Feb 2022 20:02:59 -0800 (PST) Received: from localhost ([99.197.200.79]) by smtp.gmail.com with ESMTPSA id p13-20020a056e0206cd00b002c23c551420sm7078911ils.36.2022.02.28.20.02.57 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 28 Feb 2022 20:02:59 -0800 (PST) Date: Mon, 28 Feb 2022 20:02:53 -0800 From: John Fastabend To: Wang Yufen , john.fastabend@gmail.com, daniel@iogearbox.net, jakub@cloudflare.com, lmb@cloudflare.com, davem@davemloft.net, bpf@vger.kernel.org Cc: edumazet@google.com, yoshfuji@linux-ipv6.org, dsahern@kernel.org, kuba@kernel.org, ast@kernel.org, andrii@kernel.org, kafai@fb.com, songliubraving@fb.com, yhs@fb.com, kpsingh@kernel.org, netdev@vger.kernel.org, Wang Yufen Message-ID: <621d9aed541f_8c47920864@john.notmuch> In-Reply-To: <20220225014929.942444-3-wangyufen@huawei.com> References: <20220225014929.942444-1-wangyufen@huawei.com> <20220225014929.942444-3-wangyufen@huawei.com> Subject: RE: [PATCH bpf-next 2/4] bpf, sockmap: Fix memleak in tcp_bpf_sendmsg while sk msg is full Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Wang Yufen wrote: > If tcp_bpf_sendmsg() is running while sk msg is full, sk_msg_alloc() > returns -ENOSPC, tcp_bpf_sendmsg() goto wait for memory. If partial memory > has been alloced by sk_msg_alloc(), that is, msg_tx->sg.size is greater > than osize after sk_msg_alloc(), memleak occurs. To fix we use > sk_msg_trim() to release the allocated memory, then goto wait for memory. Small nit, "sk_msg_alloc() returns -ENOSPC" should be something like, "when sk_msg_alloc() returns -ENOMEM error,..." That error path is from ENOMEM not the ENOSPC. But nice find thanks! I think we might have seen this in a couple cases on our side as well. > > This issue can cause the following info: > WARNING: CPU: 3 PID: 7950 at net/core/stream.c:208 sk_stream_kill_queues+0xd4/0x1a0 > Call Trace: > > inet_csk_destroy_sock+0x55/0x110 > __tcp_close+0x279/0x470 > tcp_close+0x1f/0x60 > inet_release+0x3f/0x80 > __sock_release+0x3d/0xb0 > sock_close+0x11/0x20 > __fput+0x92/0x250 > task_work_run+0x6a/0xa0 > do_exit+0x33b/0xb60 > do_group_exit+0x2f/0xa0 > get_signal+0xb6/0x950 > arch_do_signal_or_restart+0xac/0x2a0 > exit_to_user_mode_prepare+0xa9/0x200 > syscall_exit_to_user_mode+0x12/0x30 > do_syscall_64+0x46/0x80 > entry_SYSCALL_64_after_hwframe+0x44/0xae > > > WARNING: CPU: 3 PID: 2094 at net/ipv4/af_inet.c:155 inet_sock_destruct+0x13c/0x260 > Call Trace: > > __sk_destruct+0x24/0x1f0 > sk_psock_destroy+0x19b/0x1c0 > process_one_work+0x1b3/0x3c0 > kthread+0xe6/0x110 > ret_from_fork+0x22/0x30 > > > Fixes: 604326b41a6f ("bpf, sockmap: convert to generic sk_msg interface") > Signed-off-by: Wang Yufen > --- > net/ipv4/tcp_bpf.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/net/ipv4/tcp_bpf.c b/net/ipv4/tcp_bpf.c > index 9b9b02052fd3..ac9f491cc139 100644 > --- a/net/ipv4/tcp_bpf.c > +++ b/net/ipv4/tcp_bpf.c > @@ -421,8 +421,10 @@ static int tcp_bpf_sendmsg(struct sock *sk, struct msghdr *msg, size_t size) > osize = msg_tx->sg.size; > err = sk_msg_alloc(sk, msg_tx, msg_tx->sg.size + copy, msg_tx->sg.end - 1); > if (err) { > - if (err != -ENOSPC) > + if (err != -ENOSPC) { > + sk_msg_trim(sk, msg_tx, osize); > goto wait_for_memory; > + } > enospc = true; > copy = msg_tx->sg.size - osize; > } > -- > 2.25.1 > Acked-by: John Fastabend