From patchwork Wed Aug 21 03:07:44 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Cong Wang X-Patchwork-Id: 13770744 X-Patchwork-Delegate: kuba@kernel.org Received: from mail-pf1-f169.google.com (mail-pf1-f169.google.com [209.85.210.169]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9668D3FF1; Wed, 21 Aug 2024 03:08:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.169 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724209691; cv=none; b=gpRV/uaiNnXCe5d7x06QM5tnrzuhEVeKXLnmYORXYQsxvhEOvIwKI3HLHr1iXcH2TlLc+Sltm+t8jNzJlQD2yGzy0Xe7caKjG0z957j0L3Uzfy8Gmzv0hrGLdLbDRJHo2Zl7xW7CQJ0YyOiMaAsyfiBGCTeZMnFyN4sh782CDuI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724209691; c=relaxed/simple; bh=bVNwORlRdJmHiJxBuirTCV/r+gzCqkmi/3IrtQSQvmo=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=u9LV6EsZK5s7KqEr0kcWjj6HOq2mVdHX87jw5QOs2vsf5R6uiC7Qmo1W2iAPfZ/Bi5R97vAd7ZB4j3kyWEZjbvfnCxWu0m8hLzXwmv99j711u9I6AKsf+xqzfV+GeflW4rwcBPRSKha8IpRkyVCosNWjYCAYI0hBLDUVfIRmMdQ= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=hdM4VeE6; arc=none smtp.client-ip=209.85.210.169 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="hdM4VeE6" Received: by mail-pf1-f169.google.com with SMTP id d2e1a72fcca58-70f5ef740b7so5582142b3a.2; Tue, 20 Aug 2024 20:08:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1724209688; x=1724814488; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=ysc84ktuJkruKkhoctNQyWbQyN7dUXlVIHB4wrqTpuU=; b=hdM4VeE6kO9RJHx1IUgS1bfUY/rsU7aEAQiTzUOmed+6iDzUC13EOAk01ArazwyaVU 8WU8K27Tn2VyEQWDVKyh6k8Y5mEjT+2RGgfidM7gPOhkbW9+ypPhyWe4xTD2okBbptAQ pR71UQzydZ/k+G+qxDLhkMKKEmYdkQQ21TnCKBnNQWFGPYrW3OQ3X9D/TEHLRnMJ2vnj 1erONoyKLye23Ps28BXc0ON72CZ98KrXQWRmryZiFclKb/zyheFYXgCIRU0ybZqMJtCD fzVO8nC5yCDL+gldcDYwEgi6WYzI4SVWmsvoZyGaLZFrHYtqJHQMH0Q66FdYJnocErqm PISg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1724209688; x=1724814488; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=ysc84ktuJkruKkhoctNQyWbQyN7dUXlVIHB4wrqTpuU=; b=CDjMcujHRKyI9Q5RZKgamG2t8la1uZMStUMBzcRyLxd47tCG9fYz7dDXLLVpPigY43 0OOMuTaGFVky++AtKu6lu3lxc8Rorf4h79aJlZSltmPgMzEo/jZ0/+wpYtVHEf5iWddC arzOXv5MggM74frjkisBzELSy5rOWrX3oAMF106cF0UbPoIa8Q8nllclNzMojDnboiMI HcyLIzYywRvFKzNJOTR4xyEqMWC1SSxOl+/iKBhnAR88xpSlO1AXFqwgBz39XDa2EiFp AnGGGXp82zkbm1bVpg21Q0TFMDwZzKlVQahQMjLuR58jQmls3nNKLccnHSYGeWHjDJrf Zi3w== X-Gm-Message-State: AOJu0YzZMmSTuzMojmVKWvcSXBAme0nj5Rrl7MrbZ7h3lK6AxqaBXjhg AerVCl/MLQS4sGAHncMU+3gxJdZygtYFGEC8SWQmmbQbPvZ3lDMPSNrI7g== X-Google-Smtp-Source: AGHT+IGQ8e3HdvHRNyrZ1Dxk82HHFf5ab2en8P9N824Mu+UsDhLL8veJqUKKh9fCqo6dXs1N6IHPdA== X-Received: by 2002:a05:6a20:841e:b0:1c4:818c:299d with SMTP id adf61e73a8af0-1cad7f72934mr1838306637.11.1724209688479; Tue, 20 Aug 2024 20:08:08 -0700 (PDT) Received: from pop-os.hsd1.ca.comcast.net ([2601:647:6881:9060:a83:7ca8:f92a:b089]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-201f02fb470sm84603105ad.9.2024.08.20.20.08.07 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 20 Aug 2024 20:08:07 -0700 (PDT) From: Cong Wang To: netdev@vger.kernel.org Cc: bpf@vger.kernel.org, Cong Wang , syzbot+58c03971700330ce14d8@syzkaller.appspotmail.com, John Fastabend , Jakub Sitnicki Subject: [Patch bpf] tcp_bpf: fix return value of tcp_bpf_sendmsg() Date: Tue, 20 Aug 2024 20:07:44 -0700 Message-Id: <20240821030744.320934-1-xiyou.wangcong@gmail.com> X-Mailer: git-send-email 2.34.1 Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Patchwork-Delegate: bpf@iogearbox.net From: Cong Wang When we cork messages in psock->cork, the last message triggers the flushing will result in sending a sk_msg larger than the current message size. In this case, in tcp_bpf_send_verdict(), 'copied' becomes negative at least in the following case: 468 case __SK_DROP: 469 default: 470 sk_msg_free_partial(sk, msg, tosend); 471 sk_msg_apply_bytes(psock, tosend); 472 *copied -= (tosend + delta); // <==== HERE 473 return -EACCES; Therefore, it could lead to the following BUG with a proper value of 'copied' (thanks to syzbot). We should not use negative 'copied' as a return value here. ------------[ cut here ]------------ kernel BUG at net/socket.c:733! Internal error: Oops - BUG: 00000000f2000800 [#1] PREEMPT SMP Modules linked in: CPU: 0 UID: 0 PID: 3265 Comm: syz-executor510 Not tainted 6.11.0-rc3-syzkaller-00060-gd07b43284ab3 #0 Hardware name: linux,dummy-virt (DT) pstate: 61400009 (nZCv daif +PAN -UAO -TCO +DIT -SSBS BTYPE=--) pc : sock_sendmsg_nosec net/socket.c:733 [inline] pc : sock_sendmsg_nosec net/socket.c:728 [inline] pc : __sock_sendmsg+0x5c/0x60 net/socket.c:745 lr : sock_sendmsg_nosec net/socket.c:730 [inline] lr : __sock_sendmsg+0x54/0x60 net/socket.c:745 sp : ffff800088ea3b30 x29: ffff800088ea3b30 x28: fbf00000062bc900 x27: 0000000000000000 x26: ffff800088ea3bc0 x25: ffff800088ea3bc0 x24: 0000000000000000 x23: f9f00000048dc000 x22: 0000000000000000 x21: ffff800088ea3d90 x20: f9f00000048dc000 x19: ffff800088ea3d90 x18: 0000000000000001 x17: 0000000000000000 x16: 0000000000000000 x15: 000000002002ffaf x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000 x11: 0000000000000000 x10: ffff8000815849c0 x9 : ffff8000815b49c0 x8 : 0000000000000000 x7 : 000000000000003f x6 : 0000000000000000 x5 : 00000000000007e0 x4 : fff07ffffd239000 x3 : fbf00000062bc900 x2 : 0000000000000000 x1 : 0000000000000000 x0 : 00000000fffffdef Call trace: sock_sendmsg_nosec net/socket.c:733 [inline] __sock_sendmsg+0x5c/0x60 net/socket.c:745 ____sys_sendmsg+0x274/0x2ac net/socket.c:2597 ___sys_sendmsg+0xac/0x100 net/socket.c:2651 __sys_sendmsg+0x84/0xe0 net/socket.c:2680 __do_sys_sendmsg net/socket.c:2689 [inline] __se_sys_sendmsg net/socket.c:2687 [inline] __arm64_sys_sendmsg+0x24/0x30 net/socket.c:2687 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x48/0x110 arch/arm64/kernel/syscall.c:49 el0_svc_common.constprop.0+0x40/0xe0 arch/arm64/kernel/syscall.c:132 do_el0_svc+0x1c/0x28 arch/arm64/kernel/syscall.c:151 el0_svc+0x34/0xec arch/arm64/kernel/entry-common.c:712 el0t_64_sync_handler+0x100/0x12c arch/arm64/kernel/entry-common.c:730 el0t_64_sync+0x19c/0x1a0 arch/arm64/kernel/entry.S:598 Code: f9404463 d63f0060 3108441f 54fffe81 (d4210000) ---[ end trace 0000000000000000 ]--- Fixes: 4f738adba30a ("bpf: create tcp_bpf_ulp allowing BPF to monitor socket TX/RX data") Reported-by: syzbot+58c03971700330ce14d8@syzkaller.appspotmail.com Cc: John Fastabend Cc: Jakub Sitnicki Signed-off-by: Cong Wang Reviewed-by: John Fastabend Acked-by: Martin KaFai Lau --- net/ipv4/tcp_bpf.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/ipv4/tcp_bpf.c b/net/ipv4/tcp_bpf.c index 53b0d62fd2c2..fe6178715ba0 100644 --- a/net/ipv4/tcp_bpf.c +++ b/net/ipv4/tcp_bpf.c @@ -577,7 +577,7 @@ static int tcp_bpf_sendmsg(struct sock *sk, struct msghdr *msg, size_t size) err = sk_stream_error(sk, msg->msg_flags, err); release_sock(sk); sk_psock_put(sk, psock); - return copied ? copied : err; + return copied > 0 ? copied : err; } enum {