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 X-Spam-Level: X-Spam-Status: No, score=-12.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 50F7DC4363D for ; Fri, 2 Oct 2020 14:23:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 04639206FA for ; Fri, 2 Oct 2020 14:23:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="XQgyxL8N" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387939AbgJBOXe (ORCPT ); Fri, 2 Oct 2020 10:23:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53574 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726090AbgJBOXe (ORCPT ); Fri, 2 Oct 2020 10:23:34 -0400 Received: from mail-pf1-x442.google.com (mail-pf1-x442.google.com [IPv6:2607:f8b0:4864:20::442]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2DDB5C0613D0; Fri, 2 Oct 2020 07:23:34 -0700 (PDT) Received: by mail-pf1-x442.google.com with SMTP id o20so1318369pfp.11; Fri, 02 Oct 2020 07:23:34 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=OjNQvI2ijIO/M2pfT2smqs+ynvGtDPzeT8cJRRsXgHA=; b=XQgyxL8NJ6EiknRfuDKYULLI52Ibs2uLUiO6B6vlyBB+ov5yWWDoKMk1wvbfEhqziB cjY7Yv6hyXrGj9EbqxQM8bFCRQ9UHhuFuwQc/WDIhQOMElOsiUaKfVpK+H1J5GxIfhQJ W01i0uNznz0D96s0WOyNlnAOtHl+U70MpfaFFdpO34u6TwH8lqtpMIhbeUE8dYltT57i UwLjaFz6nTl0SQ4fA8bu7nP9GxRHbraFpFtm+ZjcabA5R6IIYcSqU3V7QZ9XmXEDt1gC 9zUp0/D4n7NwevTNapoSi57vEk8Ms6o3lws3V3eSl1IWMy+VYhziNL6MALzJyNzKasFK 9aMg== 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:in-reply-to :references:mime-version:content-transfer-encoding; bh=OjNQvI2ijIO/M2pfT2smqs+ynvGtDPzeT8cJRRsXgHA=; b=GJ/NMj7iIbn700XwMe5ou55FovI/GMnd2w3OI1PuvNaFT3wurA1TgHZ8YCVVAPgjHz FHS4cfk8vMGb0KjHOs8FQmpBasMFty7xTwmafu4IT4oFL/D2cUlHhIFV8CXIuY4UgwgG 1NmJFn9kI8zGuB249HGM1cJfAgYJgGe/WJDbZtSMegOBg4KtNNbPi8eHPbkM9XfVQLYn VUb0T+4YyD06kMIG/QuP/6+9a2BrVXrGB0q1b8aFAADQChrFcmK+3LFiOoGqh0lVhaDl QwXbn5otXthkJL2yCXgduvUIUT/IsGv71orLHyc44UpecOowG5+lnjkEObI4/LZoR8ky PklA== X-Gm-Message-State: AOAM530bOPkEpirx+RqpVGXkPfBkedo/C8lqFNnP4P1d28Qt4D6YE7ao beP+KtnkOb5rbhHkiWT3rg== X-Google-Smtp-Source: ABdhPJxV0D5CAPrY5aLgnnIaonU6JK0L9yfh1hftGF3Vuyfk6tWfcImIpm0lhbKAf6hbESmEjhP2Zw== X-Received: by 2002:aa7:8d15:0:b029:142:2501:39fe with SMTP id j21-20020aa78d150000b0290142250139femr2979520pfe.77.1601648613591; Fri, 02 Oct 2020 07:23:33 -0700 (PDT) Received: from localhost.localdomain ([161.117.41.183]) by smtp.gmail.com with ESMTPSA id gi20sm1786628pjb.28.2020.10.02.07.23.27 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 02 Oct 2020 07:23:32 -0700 (PDT) From: Peilin Ye To: Jens Axboe , syzbot Cc: Peilin Ye , Dan Carpenter , Arnd Bergmann , Greg Kroah-Hartman , glider@google.com, Anant Thazhemadam , linux-kernel-mentees@lists.linuxfoundation.org, linux-block@vger.kernel.org, syzkaller-bugs@googlegroups.com, linux-kernel@vger.kernel.org Subject: [PATCH v4] block/scsi-ioctl: Fix kernel-infoleak in scsi_put_cdrom_generic_arg() Date: Fri, 2 Oct 2020 10:22:23 -0400 Message-Id: <20201002142223.9482-1-yepeilin.cs@gmail.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <000000000000a24fa705ae29dc6c@google.com> References: <000000000000a24fa705ae29dc6c@google.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org scsi_put_cdrom_generic_arg() is copying uninitialized stack memory to userspace, since the compiler may leave a 3-byte hole in the middle of `cgc32`. Fix it by adding a padding field to `struct compat_cdrom_generic_command`. Cc: stable@vger.kernel.org Fixes: f3ee6e63a9df ("compat_ioctl: move CDROM_SEND_PACKET handling into scsi") Suggested-by: Dan Carpenter Suggested-by: Arnd Bergmann Reported-by: syzbot+85433a479a646a064ab3@syzkaller.appspotmail.com Signed-off-by: Peilin Ye --- v3: https://lore.kernel.org/lkml/20200909095057.1214104-1-yepeilin.cs@gmail.com/ Changes in v4: - Change "Prevent" in the title to "Fix", and improve the commit message, since syzbot has reported it as a "real" bug. - Add syzbot Reported-by: tag. Changes in v3: - Improve commit message. scsi_put_cdrom_generic_arg() does not *always* leak kernel information. It is compiler dependent. Reference: https://www.nccgroup.com/us/about-us/newsroom-and-events/blog/2019/october/padding-the-struct-how-a-compiler-optimization-can-disclose-stack-memory/ - Base the patch against mainline 5.9-rc4. Change in v2: - Add a padding field to `struct compat_cdrom_generic_command`, instead of doing memset() on `cgc32`. (Suggested by Jens Axboe ) $ # before $ pahole -C "compat_cdrom_generic_command" !$ pahole -C "compat_cdrom_generic_command" block/scsi_ioctl.o struct compat_cdrom_generic_command { unsigned char cmd[12]; /* 0 12 */ compat_caddr_t buffer; /* 12 4 */ compat_uint_t buflen; /* 16 4 */ compat_int_t stat; /* 20 4 */ compat_caddr_t sense; /* 24 4 */ unsigned char data_direction; /* 28 1 */ /* XXX 3 bytes hole, try to pack */ compat_int_t quiet; /* 32 4 */ compat_int_t timeout; /* 36 4 */ compat_caddr_t reserved[1]; /* 40 4 */ /* size: 44, cachelines: 1, members: 9 */ /* sum members: 41, holes: 1, sum holes: 3 */ /* last cacheline: 44 bytes */ }; $ # after $ pahole -C "compat_cdrom_generic_command" block/scsi_ioctl.o struct compat_cdrom_generic_command { unsigned char cmd[12]; /* 0 12 */ compat_caddr_t buffer; /* 12 4 */ compat_uint_t buflen; /* 16 4 */ compat_int_t stat; /* 20 4 */ compat_caddr_t sense; /* 24 4 */ unsigned char data_direction; /* 28 1 */ unsigned char pad[3]; /* 29 3 */ compat_int_t quiet; /* 32 4 */ compat_int_t timeout; /* 36 4 */ compat_caddr_t reserved[1]; /* 40 4 */ /* size: 44, cachelines: 1, members: 10 */ /* last cacheline: 44 bytes */ }; $ _ block/scsi_ioctl.c | 1 + 1 file changed, 1 insertion(+) diff --git a/block/scsi_ioctl.c b/block/scsi_ioctl.c index ef722f04f88a..72108404718f 100644 --- a/block/scsi_ioctl.c +++ b/block/scsi_ioctl.c @@ -651,6 +651,7 @@ struct compat_cdrom_generic_command { compat_int_t stat; compat_caddr_t sense; unsigned char data_direction; + unsigned char pad[3]; compat_int_t quiet; compat_int_t timeout; compat_caddr_t reserved[1]; -- 2.25.1 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 X-Spam-Level: X-Spam-Status: No, score=-12.5 required=3.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED,DKIM_INVALID,DKIM_SIGNED,FREEMAIL_FORGED_FROMDOMAIN, FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 DDF3BC4363D for ; Fri, 2 Oct 2020 14:23:37 +0000 (UTC) Received: from hemlock.osuosl.org (smtp2.osuosl.org [140.211.166.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 74054206DB for ; Fri, 2 Oct 2020 14:23:37 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="XQgyxL8N" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 74054206DB Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linux-kernel-mentees-bounces@lists.linuxfoundation.org Received: from localhost (localhost [127.0.0.1]) by hemlock.osuosl.org (Postfix) with ESMTP id 4FF3C87390; Fri, 2 Oct 2020 14:23:37 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from hemlock.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id n4RC1-axpNEU; Fri, 2 Oct 2020 14:23:36 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by hemlock.osuosl.org (Postfix) with ESMTP id 918E7872EC; Fri, 2 Oct 2020 14:23:36 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 7AD08C016F; Fri, 2 Oct 2020 14:23:36 +0000 (UTC) Received: from silver.osuosl.org (smtp3.osuosl.org [140.211.166.136]) by lists.linuxfoundation.org (Postfix) with ESMTP id 1A0E1C0051 for ; Fri, 2 Oct 2020 14:23:35 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by silver.osuosl.org (Postfix) with ESMTP id 082F2274DB for ; Fri, 2 Oct 2020 14:23:35 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from silver.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id YJM+zBsKeDJs for ; Fri, 2 Oct 2020 14:23:34 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from mail-pg1-f193.google.com (mail-pg1-f193.google.com [209.85.215.193]) by silver.osuosl.org (Postfix) with ESMTPS id 1E3A5204DB for ; Fri, 2 Oct 2020 14:23:34 +0000 (UTC) Received: by mail-pg1-f193.google.com with SMTP id 34so853304pgo.13 for ; Fri, 02 Oct 2020 07:23:34 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=OjNQvI2ijIO/M2pfT2smqs+ynvGtDPzeT8cJRRsXgHA=; b=XQgyxL8NJ6EiknRfuDKYULLI52Ibs2uLUiO6B6vlyBB+ov5yWWDoKMk1wvbfEhqziB cjY7Yv6hyXrGj9EbqxQM8bFCRQ9UHhuFuwQc/WDIhQOMElOsiUaKfVpK+H1J5GxIfhQJ W01i0uNznz0D96s0WOyNlnAOtHl+U70MpfaFFdpO34u6TwH8lqtpMIhbeUE8dYltT57i UwLjaFz6nTl0SQ4fA8bu7nP9GxRHbraFpFtm+ZjcabA5R6IIYcSqU3V7QZ9XmXEDt1gC 9zUp0/D4n7NwevTNapoSi57vEk8Ms6o3lws3V3eSl1IWMy+VYhziNL6MALzJyNzKasFK 9aMg== 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:in-reply-to :references:mime-version:content-transfer-encoding; bh=OjNQvI2ijIO/M2pfT2smqs+ynvGtDPzeT8cJRRsXgHA=; b=rsiahIJVaHbQyE8Fjt9PTbwdMLu9xlvZ5RlDoBog/k3Q+h/nI1lxaehgZYPMK4vrln OzG5CRTfj/pLh9rkLeDJmfQDYhiYfdAZESlFFWYeDGwo0mCkzbRU0HeOR/n4WhRcS2EL +ny2w+LLr2yZ7zGLUgqGXoCcXtNFhJclMtsFaDPzvR8rfx+oWBF69tLl6DsQoMfiPn+P rxAZ0XboVA8/Bzny3ErggNRFO8u1UKqsoDJVccuOb3ZvvEps5SiKepJwOvsiUrhWADs9 c3cXz3TN8+ttNYpaCQ6S+AHS+9uJJTbaZaRaxIURqytKCRCgtZfkABMM9NVZEMgzASSp r9Tw== X-Gm-Message-State: AOAM530acHO+abaFFzvbngLKAvbIHkgbFvSQ25V0NwUlnmj3J/HieEiM usSAgJm/P/JkJKlHQ0nQ7A== X-Google-Smtp-Source: ABdhPJxV0D5CAPrY5aLgnnIaonU6JK0L9yfh1hftGF3Vuyfk6tWfcImIpm0lhbKAf6hbESmEjhP2Zw== X-Received: by 2002:aa7:8d15:0:b029:142:2501:39fe with SMTP id j21-20020aa78d150000b0290142250139femr2979520pfe.77.1601648613591; Fri, 02 Oct 2020 07:23:33 -0700 (PDT) Received: from localhost.localdomain ([161.117.41.183]) by smtp.gmail.com with ESMTPSA id gi20sm1786628pjb.28.2020.10.02.07.23.27 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 02 Oct 2020 07:23:32 -0700 (PDT) From: Peilin Ye To: Jens Axboe , syzbot Date: Fri, 2 Oct 2020 10:22:23 -0400 Message-Id: <20201002142223.9482-1-yepeilin.cs@gmail.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <000000000000a24fa705ae29dc6c@google.com> References: <000000000000a24fa705ae29dc6c@google.com> MIME-Version: 1.0 Cc: Anant Thazhemadam , Arnd Bergmann , syzkaller-bugs@googlegroups.com, linux-kernel@vger.kernel.org, linux-block@vger.kernel.org, glider@google.com, linux-kernel-mentees@lists.linuxfoundation.org, Peilin Ye , Dan Carpenter Subject: [Linux-kernel-mentees] [PATCH v4] block/scsi-ioctl: Fix kernel-infoleak in scsi_put_cdrom_generic_arg() X-BeenThere: linux-kernel-mentees@lists.linuxfoundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: linux-kernel-mentees-bounces@lists.linuxfoundation.org Sender: "Linux-kernel-mentees" scsi_put_cdrom_generic_arg() is copying uninitialized stack memory to userspace, since the compiler may leave a 3-byte hole in the middle of `cgc32`. Fix it by adding a padding field to `struct compat_cdrom_generic_command`. Cc: stable@vger.kernel.org Fixes: f3ee6e63a9df ("compat_ioctl: move CDROM_SEND_PACKET handling into scsi") Suggested-by: Dan Carpenter Suggested-by: Arnd Bergmann Reported-by: syzbot+85433a479a646a064ab3@syzkaller.appspotmail.com Signed-off-by: Peilin Ye --- v3: https://lore.kernel.org/lkml/20200909095057.1214104-1-yepeilin.cs@gmail.com/ Changes in v4: - Change "Prevent" in the title to "Fix", and improve the commit message, since syzbot has reported it as a "real" bug. - Add syzbot Reported-by: tag. Changes in v3: - Improve commit message. scsi_put_cdrom_generic_arg() does not *always* leak kernel information. It is compiler dependent. Reference: https://www.nccgroup.com/us/about-us/newsroom-and-events/blog/2019/october/padding-the-struct-how-a-compiler-optimization-can-disclose-stack-memory/ - Base the patch against mainline 5.9-rc4. Change in v2: - Add a padding field to `struct compat_cdrom_generic_command`, instead of doing memset() on `cgc32`. (Suggested by Jens Axboe ) $ # before $ pahole -C "compat_cdrom_generic_command" !$ pahole -C "compat_cdrom_generic_command" block/scsi_ioctl.o struct compat_cdrom_generic_command { unsigned char cmd[12]; /* 0 12 */ compat_caddr_t buffer; /* 12 4 */ compat_uint_t buflen; /* 16 4 */ compat_int_t stat; /* 20 4 */ compat_caddr_t sense; /* 24 4 */ unsigned char data_direction; /* 28 1 */ /* XXX 3 bytes hole, try to pack */ compat_int_t quiet; /* 32 4 */ compat_int_t timeout; /* 36 4 */ compat_caddr_t reserved[1]; /* 40 4 */ /* size: 44, cachelines: 1, members: 9 */ /* sum members: 41, holes: 1, sum holes: 3 */ /* last cacheline: 44 bytes */ }; $ # after $ pahole -C "compat_cdrom_generic_command" block/scsi_ioctl.o struct compat_cdrom_generic_command { unsigned char cmd[12]; /* 0 12 */ compat_caddr_t buffer; /* 12 4 */ compat_uint_t buflen; /* 16 4 */ compat_int_t stat; /* 20 4 */ compat_caddr_t sense; /* 24 4 */ unsigned char data_direction; /* 28 1 */ unsigned char pad[3]; /* 29 3 */ compat_int_t quiet; /* 32 4 */ compat_int_t timeout; /* 36 4 */ compat_caddr_t reserved[1]; /* 40 4 */ /* size: 44, cachelines: 1, members: 10 */ /* last cacheline: 44 bytes */ }; $ _ block/scsi_ioctl.c | 1 + 1 file changed, 1 insertion(+) diff --git a/block/scsi_ioctl.c b/block/scsi_ioctl.c index ef722f04f88a..72108404718f 100644 --- a/block/scsi_ioctl.c +++ b/block/scsi_ioctl.c @@ -651,6 +651,7 @@ struct compat_cdrom_generic_command { compat_int_t stat; compat_caddr_t sense; unsigned char data_direction; + unsigned char pad[3]; compat_int_t quiet; compat_int_t timeout; compat_caddr_t reserved[1]; -- 2.25.1 _______________________________________________ Linux-kernel-mentees mailing list Linux-kernel-mentees@lists.linuxfoundation.org https://lists.linuxfoundation.org/mailman/listinfo/linux-kernel-mentees