From patchwork Wed Jan 26 09:20:43 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marta Rybczynska X-Patchwork-Id: 2952 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 aws-us-west-2-korg-lkml-1.web.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.lore.kernel.org (Postfix) with ESMTP id 68AD2C28CF5 for ; Wed, 26 Jan 2022 09:21:09 +0000 (UTC) Received: from mail-ej1-f42.google.com (mail-ej1-f42.google.com [209.85.218.42]) by mx.groups.io with SMTP id smtpd.web11.10596.1643188867706564163 for ; Wed, 26 Jan 2022 01:21:08 -0800 Authentication-Results: mx.groups.io; dkim=pass header.i=@gmail.com header.s=20210112 header.b=eOam/sV0; spf=pass (domain: gmail.com, ip: 209.85.218.42, mailfrom: rybczynska@gmail.com) Received: by mail-ej1-f42.google.com with SMTP id m4so37604782ejb.9 for ; Wed, 26 Jan 2022 01:21:07 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=VNCsv/32jVus/Z0AoZJUPeUpYC8FFkF5h4ZVVyOBn6A=; b=eOam/sV0avlKqT5g25xg0f3eSTB6ypprBZ/LdHMNd8D/l0ZPDw2rKLb9JRU8jHmFQj Ud9NSMzzk4rafQmEzNXLgtYoEtiol048zvq6AH8kqFcGUvX0i0hpISydhkBeReMuDqfO +u2k5cAvOeMyf3QqYclqv7yGJeT4yTJ2FpgcSe72IAR822n9GONvukNpVdHVmOk5AUXC qvDU3xK8ZirgdBVP34L7eUoBn35qDmpY+dWLIhrV5vVOlx5777dKegSioEcCswemrhUS Aoxxl4sMUc3EPoZwks7+0VnjfCZGGfI85o7cxH4xfYGFYAef4bil2kUsv4GQJEh5bxs9 a9bw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=VNCsv/32jVus/Z0AoZJUPeUpYC8FFkF5h4ZVVyOBn6A=; b=lceHOyf/v8uKyyaFrtce/WsHY//JYRuHl0pzcr7/rvNMBFAg7d6Y61S6xzvt21xdsF wgzAAZWBFKE0wEm9fWC/wFy7NDAjVj/avvK6cC2JJuU4Gke8ZYcvmKGSS71Umlpp7qpq zgTAaiNkiP2c9sTYhn9xlGI/ThaIWnrnzyQIdaA1pXNMOtPAfeMMQQdXlcS0tGl2anD7 Z/Uy7NwYVHpNmpgMcvhoXpOy5QVTi0WRXMhj/RItKL2hnSqvQ6fJXMKnxHw/Q3GA7WVE Hbb7DTRJP1zlOzOUllj/mTJEt5hwieF+APg2P7vr7299l8aPUT9nrPsx5zxXv3jxZ6Z5 AkMw== X-Gm-Message-State: AOAM530FT4e7DH6JRU/AntozYP+rtvcF9S9SaY9xo+105uxmpwnyJR1Z cdrP1PQmC/JXDgYtLdduR6rq67sky6s= X-Google-Smtp-Source: ABdhPJxFiyp2hvyVQuSblutHxMUJqFtXuT1UlBH01iXVCMp21ugAimSpWZDG/UNaSQjkP0mFQpPtIA== X-Received: by 2002:a17:907:6e29:: with SMTP id sd41mr12032027ejc.276.1643188865705; Wed, 26 Jan 2022 01:21:05 -0800 (PST) Received: from localhost.localdomain ([80.215.178.46]) by smtp.gmail.com with ESMTPSA id j2sm7165750ejc.223.2022.01.26.01.21.04 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 26 Jan 2022 01:21:05 -0800 (PST) From: Marta Rybczynska To: openembedded-core@lists.openembedded.org, anuj.mittal@intel.com, steve@sakoman.com Cc: Marta Rybczynska , Marta Rybczynska Subject: [dunfell][OE-core][PATCH 1/2] grub: add a fix for CVE-2020-25632 Date: Wed, 26 Jan 2022 10:20:43 +0100 Message-Id: <20220126092044.2206160-1-rybczynska@gmail.com> X-Mailer: git-send-email 2.33.0 MIME-Version: 1.0 List-Id: X-Webhook-Received: from li982-79.members.linode.com [45.33.32.79] by aws-us-west-2-korg-lkml-1.web.codeaurora.org with HTTPS for ; Wed, 26 Jan 2022 09:21:09 -0000 X-Groupsio-URL: https://lists.openembedded.org/g/openembedded-core/message/160963 Fix grub issue with module dereferencing. From the official description from NVD [1]: The rmmod implementation allows the unloading of a module used as a dependency without checking if any other dependent module is still loaded leading to a use-after-free scenario. This could allow arbitrary code to be executed or a bypass of Secure Boot protections. This patch is a part of a bigger security collection for grub [2]. [1] https://nvd.nist.gov/vuln/detail/CVE-2020-25632 [2] https://lists.gnu.org/archive/html/grub-devel/2021-03/msg00007.html Signed-off-by: Marta Rybczynska --- .../grub/files/CVE-2020-25632.patch | 90 +++++++++++++++++++ meta/recipes-bsp/grub/grub2.inc | 1 + 2 files changed, 91 insertions(+) create mode 100644 meta/recipes-bsp/grub/files/CVE-2020-25632.patch diff --git a/meta/recipes-bsp/grub/files/CVE-2020-25632.patch b/meta/recipes-bsp/grub/files/CVE-2020-25632.patch new file mode 100644 index 0000000000..0b37c72f0f --- /dev/null +++ b/meta/recipes-bsp/grub/files/CVE-2020-25632.patch @@ -0,0 +1,90 @@ +From 7630ec5397fe418276b360f9011934b8c034936c Mon Sep 17 00:00:00 2001 +From: Javier Martinez Canillas +Date: Tue, 29 Sep 2020 14:08:55 +0200 +Subject: [PATCH] dl: Only allow unloading modules that are not dependencies + +When a module is attempted to be removed its reference counter is always +decremented. This means that repeated rmmod invocations will cause the +module to be unloaded even if another module depends on it. + +This may lead to a use-after-free scenario allowing an attacker to execute +arbitrary code and by-pass the UEFI Secure Boot protection. + +While being there, add the extern keyword to some function declarations in +that header file. + +Fixes: CVE-2020-25632 + +Reported-by: Chris Coulson +Signed-off-by: Javier Martinez Canillas +Reviewed-by: Daniel Kiper + +Upstream-Status: Backport [https://git.savannah.gnu.org/cgit/grub.git/commit/?id=7630ec5397fe418276b360f9011934b8c034936c] +CVE: CVE-2020-25632 +Signed-off-by: Marta Rybczynska +--- + grub-core/commands/minicmd.c | 7 +++++-- + grub-core/kern/dl.c | 9 +++++++++ + include/grub/dl.h | 8 +++++--- + 3 files changed, 19 insertions(+), 5 deletions(-) + +diff --git a/grub-core/commands/minicmd.c b/grub-core/commands/minicmd.c +index 6bbce3128..fa498931e 100644 +--- a/grub-core/commands/minicmd.c ++++ b/grub-core/commands/minicmd.c +@@ -140,8 +140,11 @@ grub_mini_cmd_rmmod (struct grub_command *cmd __attribute__ ((unused)), + if (grub_dl_is_persistent (mod)) + return grub_error (GRUB_ERR_BAD_ARGUMENT, "cannot unload persistent module"); + +- if (grub_dl_unref (mod) <= 0) +- grub_dl_unload (mod); ++ if (grub_dl_ref_count (mod) > 1) ++ return grub_error (GRUB_ERR_BAD_ARGUMENT, "cannot unload referenced module"); ++ ++ grub_dl_unref (mod); ++ grub_dl_unload (mod); + + return 0; + } +diff --git a/grub-core/kern/dl.c b/grub-core/kern/dl.c +index 48eb5e7b6..48f8a7907 100644 +--- a/grub-core/kern/dl.c ++++ b/grub-core/kern/dl.c +@@ -549,6 +549,15 @@ grub_dl_unref (grub_dl_t mod) + return --mod->ref_count; + } + ++int ++grub_dl_ref_count (grub_dl_t mod) ++{ ++ if (mod == NULL) ++ return 0; ++ ++ return mod->ref_count; ++} ++ + static void + grub_dl_flush_cache (grub_dl_t mod) + { +diff --git a/include/grub/dl.h b/include/grub/dl.h +index f03c03561..b3753c9ca 100644 +--- a/include/grub/dl.h ++++ b/include/grub/dl.h +@@ -203,9 +203,11 @@ grub_dl_t EXPORT_FUNC(grub_dl_load) (const char *name); + grub_dl_t grub_dl_load_core (void *addr, grub_size_t size); + grub_dl_t EXPORT_FUNC(grub_dl_load_core_noinit) (void *addr, grub_size_t size); + int EXPORT_FUNC(grub_dl_unload) (grub_dl_t mod); +-void grub_dl_unload_unneeded (void); +-int EXPORT_FUNC(grub_dl_ref) (grub_dl_t mod); +-int EXPORT_FUNC(grub_dl_unref) (grub_dl_t mod); ++extern void grub_dl_unload_unneeded (void); ++extern int EXPORT_FUNC(grub_dl_ref) (grub_dl_t mod); ++extern int EXPORT_FUNC(grub_dl_unref) (grub_dl_t mod); ++extern int EXPORT_FUNC(grub_dl_ref_count) (grub_dl_t mod); ++ + extern grub_dl_t EXPORT_VAR(grub_dl_head); + + #ifndef GRUB_UTIL +-- +2.33.0 + diff --git a/meta/recipes-bsp/grub/grub2.inc b/meta/recipes-bsp/grub/grub2.inc index db7c23a84a..6a17940afb 100644 --- a/meta/recipes-bsp/grub/grub2.inc +++ b/meta/recipes-bsp/grub/grub2.inc @@ -45,6 +45,7 @@ SRC_URI = "${GNU_MIRROR}/grub/grub-${PV}.tar.gz \ file://CVE-2020-27779_5.patch \ file://CVE-2020-27779_6.patch \ file://CVE-2020-27779_7.patch \ + file://CVE-2020-25632.patch \ " SRC_URI[md5sum] = "5ce674ca6b2612d8939b9e6abed32934" SRC_URI[sha256sum] = "f10c85ae3e204dbaec39ae22fa3c5e99f0665417e91c2cb49b7e5031658ba6ea"