From patchwork Fri Mar 12 16:59:48 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Dumazet X-Patchwork-Id: 12135335 X-Patchwork-Delegate: kuba@kernel.org Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CF508C433E6 for ; Fri, 12 Mar 2021 17:00:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9D5C16501D for ; Fri, 12 Mar 2021 17:00:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232520AbhCLRAZ (ORCPT ); Fri, 12 Mar 2021 12:00:25 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35296 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232389AbhCLQ77 (ORCPT ); Fri, 12 Mar 2021 11:59:59 -0500 Received: from mail-pg1-x52e.google.com (mail-pg1-x52e.google.com [IPv6:2607:f8b0:4864:20::52e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 77E50C061574 for ; Fri, 12 Mar 2021 08:59:59 -0800 (PST) Received: by mail-pg1-x52e.google.com with SMTP id p21so16252461pgl.12 for ; Fri, 12 Mar 2021 08:59:59 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=R4e0vHpXmVEA0zpvL1or9GwOS3zC6hREPl8g9mZwthg=; b=dZV7MBFapJ1xt29/IgWx9ylnQPZ89lJhaZBuGj7J4XbfTmjgnReAsv7DW8rjprrmV3 ZVmeL6aP9j1ohBOpQQWOLGZhB6G8JlYjxt4ig9V2WIjOmWaTXikGJVFBlRkzsmPilBiZ gNptAnFLUBHqd+rznn7aa5nasOuNA0RTJw5m00d5EzqXVndIthSzFiUyciL9rQdRyCPZ ykAEEXYbHOlielSFhM8dMAWJrmRNtqjwfmPuzh0zJ2BfdylwWjXRSL9RU+Pxggy4Bv2I F67/C2YMUFE0/iYhJk3xoGMU/LS/NuhFzaZkbJ0GHyU3X9yKa5TgghGiuQtrj4kSIIRu YCYA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=R4e0vHpXmVEA0zpvL1or9GwOS3zC6hREPl8g9mZwthg=; b=nTjiXhVLQx9f76//uS2ZwCndmgfL9PCRH9Qz8lGUiPntIdQPY/Xsb6jifq9/UTf5tH 9M1OVYqi7U7sWpmJFtYIOJQEgnf949VKWkRU/XiyQ/ZLY3MrhsYgXLz4Ur/KDTRGUepN xWjQicZhyRU0hVVTGEzU0bQM5C3mtcZds11kQY0nwHt+JgAYof37fXB6e3yOqKC0CWMp gCrC0OY44STe6YWZ0/t5Zxp55ISt6WJEZoQgY4bbWXCSALDmKx5R2n8L8myRB16RXiFt u2JRfaC5i/W2MDcu/TG0vEm+3+/pIxBGODWVeV/4jS1pxiRLlYOgaFN0EfzzyGVW4F49 RhFA== X-Gm-Message-State: AOAM532GDjFm8/tEyCicmJQ9CWSRxQ/G/oEeUnYhUyQ4jepuN+8BOF4i RcDx1NUnTYUZmBIj7E4r7qs= X-Google-Smtp-Source: ABdhPJxkeRZY9t1wLn5Nuwht6aKGwY1NY1ap9A01c9OV4Ly09D7I1KQmBNEapHBr3D7id3CJ9gzKRg== X-Received: by 2002:a63:d0f:: with SMTP id c15mr12342258pgl.367.1615568399077; Fri, 12 Mar 2021 08:59:59 -0800 (PST) Received: from edumazet1.svl.corp.google.com ([2620:15c:2c4:201:6452:a7e2:4139:2684]) by smtp.gmail.com with ESMTPSA id m21sm6044811pff.61.2021.03.12.08.59.57 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 12 Mar 2021 08:59:58 -0800 (PST) From: Eric Dumazet To: "David S . Miller" , Jakub Kicinski Cc: netdev , Eric Dumazet , Eric Dumazet , Courtney Cavin , syzbot Subject: [PATCH net] net: qrtr: fix a kernel-infoleak in qrtr_recvmsg() Date: Fri, 12 Mar 2021 08:59:48 -0800 Message-Id: <20210312165948.909295-1-eric.dumazet@gmail.com> X-Mailer: git-send-email 2.31.0.rc2.261.g7f71774620-goog MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org From: Eric Dumazet struct sockaddr_qrtr has a 2-byte hole, and qrtr_recvmsg() currently does not clear it before copying kernel data to user space. It might be too late to name the hole since sockaddr_qrtr structure is uapi. BUG: KMSAN: kernel-infoleak in kmsan_copy_to_user+0x9c/0xb0 mm/kmsan/kmsan_hooks.c:249 CPU: 0 PID: 29705 Comm: syz-executor.3 Not tainted 5.11.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x21c/0x280 lib/dump_stack.c:120 kmsan_report+0xfb/0x1e0 mm/kmsan/kmsan_report.c:118 kmsan_internal_check_memory+0x202/0x520 mm/kmsan/kmsan.c:402 kmsan_copy_to_user+0x9c/0xb0 mm/kmsan/kmsan_hooks.c:249 instrument_copy_to_user include/linux/instrumented.h:121 [inline] _copy_to_user+0x1ac/0x270 lib/usercopy.c:33 copy_to_user include/linux/uaccess.h:209 [inline] move_addr_to_user+0x3a2/0x640 net/socket.c:237 ____sys_recvmsg+0x696/0xd50 net/socket.c:2575 ___sys_recvmsg net/socket.c:2610 [inline] do_recvmmsg+0xa97/0x22d0 net/socket.c:2710 __sys_recvmmsg net/socket.c:2789 [inline] __do_sys_recvmmsg net/socket.c:2812 [inline] __se_sys_recvmmsg+0x24a/0x410 net/socket.c:2805 __x64_sys_recvmmsg+0x62/0x80 net/socket.c:2805 do_syscall_64+0x9f/0x140 arch/x86/entry/common.c:48 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x465f69 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f43659d6188 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000465f69 RDX: 0000000000000008 RSI: 0000000020003e40 RDI: 0000000000000003 RBP: 00000000004bfa8f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000010060 R11: 0000000000000246 R12: 000000000056bf60 R13: 0000000000a9fb1f R14: 00007f43659d6300 R15: 0000000000022000 Local variable ----addr@____sys_recvmsg created at: ____sys_recvmsg+0x168/0xd50 net/socket.c:2550 ____sys_recvmsg+0x168/0xd50 net/socket.c:2550 Bytes 2-3 of 12 are uninitialized Memory access of size 12 starts at ffff88817c627b40 Data copied to user address 0000000020000140 Fixes: bdabad3e363d ("net: Add Qualcomm IPC router") Signed-off-by: Eric Dumazet Cc: Courtney Cavin Reported-by: syzbot --- net/qrtr/qrtr.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/net/qrtr/qrtr.c b/net/qrtr/qrtr.c index edb6ac17cecabd94fe392eb4f589dbbbf7bfa2c0..dfc820ee553a0948cc64f25f5b8f9c5d0061cfd4 100644 --- a/net/qrtr/qrtr.c +++ b/net/qrtr/qrtr.c @@ -1058,6 +1058,11 @@ static int qrtr_recvmsg(struct socket *sock, struct msghdr *msg, rc = copied; if (addr) { + /* There is an anonymous 2-byte hole after sq_family, + * make sure to clear it. + */ + memset(addr, 0, sizeof(*addr)); + addr->sq_family = AF_QIPCRTR; addr->sq_node = cb->src_node; addr->sq_port = cb->src_port;