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 23D07C433EF for ; Wed, 11 May 2022 18:59:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346521AbiEKS7n (ORCPT ); Wed, 11 May 2022 14:59:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40062 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1346513AbiEKS7j (ORCPT ); Wed, 11 May 2022 14:59:39 -0400 Received: from mail-pf1-x42a.google.com (mail-pf1-x42a.google.com [IPv6:2607:f8b0:4864:20::42a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1CEED6D4C3 for ; Wed, 11 May 2022 11:59:38 -0700 (PDT) Received: by mail-pf1-x42a.google.com with SMTP id v11so2760432pff.6 for ; Wed, 11 May 2022 11:59:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=2MbxQToswSlU3uGoWcNi5INJYQyZuFk9/eAJQ7cdhmM=; b=CAnupYTRbk5GC5fKicsn72UhgiuO5+FGnHpN87ZAcpAMVTT4w/YH0sYOJ9/Tc0RzxO lQCza6ElQrlD7hiEde2IBjhNwEFNRpfIueSDbPkO7C+mO/Nl7pyoMf/XiMK/Bs8vcn+s 31Yx8MEdBlvr8VlIy/C27slzdi8rukc9+gAXnIE284BO3FYVBjNKVIlJ7W0eB5J9VuYJ 8KXyHs1ICf3Hn/Q1lEQWNtVn8DP8lwdxoO+lq9VY7lOInslCI7HV00mzbUq8bxf57lVE uVZrHtFwPw3FGwLhoXTPPLgl5vO4eQnTL0pqdJZsUITCwcR3xQVeYjkdmHCnGk0PH94h BN/Q== 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:in-reply-to :references:mime-version:content-transfer-encoding; bh=2MbxQToswSlU3uGoWcNi5INJYQyZuFk9/eAJQ7cdhmM=; b=5JUyPQBT8DDyMVrmhy2YAMg1du+07v2FTvWTsAKF84MlavAQ7CK+vJdcwbqXusy2oW hKeOWso9QH9oV1TYTpHr7KBnEcFqLVm0WzY25k94GuMylil82TwmlZxedsemmBY2nBMN DWdIA3a3Rfz3Q36qCMmaFmSvtiq2I7VpvpmwQTiWsSVCzn8JSSvksI0ZBlHTCv8ALcPk 7aCQmdRiDVDFBrw8MyjlPTR0P2hvPu6EdW9exL60fIfBbBiZLv9O1TwPqNboVqURCD2+ XxDnRUyICt3yTUZikMkzyiba+5aormpyJ8EG7oOiLul1W69ehv/FkatRP4B1KawT++tZ Ecng== X-Gm-Message-State: AOAM533yU2Nn6LtXEYk2sJKy9V0JaYdM8TlgAPiRW/N0tT9w7t57HBMk qFeKLlIndqqUrqvNfwSuVtu84A== X-Google-Smtp-Source: ABdhPJz9bBTfcx7W1OwKidWuK66EB5cdlNK1lVelNf4ILnzBY58KVHr7ms6mzbrWQdITVzEymsyxoA== X-Received: by 2002:a63:5552:0:b0:3c2:363b:abe1 with SMTP id f18-20020a635552000000b003c2363babe1mr21396007pgm.304.1652295577623; Wed, 11 May 2022 11:59:37 -0700 (PDT) Received: from localhost.localdomain ([50.39.160.154]) by smtp.gmail.com with ESMTPSA id a19-20020a17090aa51300b001d5c571f487sm280709pjq.25.2022.05.11.11.59.37 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 11 May 2022 11:59:37 -0700 (PDT) From: Tadeusz Struk To: linkinjeon@kernel.org Cc: Tadeusz Struk , Sungjong Seo , linux-fsdevel@vger.kernel.org, stable@vger.kernel.org, linux-kernel@vger.kernel.org, syzbot+a4087e40b9c13aad7892@syzkaller.appspotmail.com Subject: [PATCH v2 2/2] exfat: check if cluster num is valid Date: Wed, 11 May 2022 11:59:09 -0700 Message-Id: <20220511185909.175110-2-tadeusz.struk@linaro.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220511185909.175110-1-tadeusz.struk@linaro.org> References: <20220511185909.175110-1-tadeusz.struk@linaro.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Syzbot reported slab-out-of-bounds read in exfat_clear_bitmap. This was triggered by reproducer calling truncute with size 0, which causes the following trace: BUG: KASAN: slab-out-of-bounds in exfat_clear_bitmap+0x147/0x490 fs/exfat/balloc.c:174 Read of size 8 at addr ffff888115aa9508 by task syz-executor251/365 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack_lvl+0x1e2/0x24b lib/dump_stack.c:118 print_address_description+0x81/0x3c0 mm/kasan/report.c:233 __kasan_report mm/kasan/report.c:419 [inline] kasan_report+0x1a4/0x1f0 mm/kasan/report.c:436 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report_generic.c:309 exfat_clear_bitmap+0x147/0x490 fs/exfat/balloc.c:174 exfat_free_cluster+0x25a/0x4a0 fs/exfat/fatent.c:181 __exfat_truncate+0x99e/0xe00 fs/exfat/file.c:217 exfat_truncate+0x11b/0x4f0 fs/exfat/file.c:243 exfat_setattr+0xa03/0xd40 fs/exfat/file.c:339 notify_change+0xb76/0xe10 fs/attr.c:336 do_truncate+0x1ea/0x2d0 fs/open.c:65 Add checks to validate if cluster number is within valid range in exfat_clear_bitmap() and exfat_set_bitmap() Cc: Namjae Jeon Cc: Sungjong Seo Cc: linux-fsdevel@vger.kernel.org Cc: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org Link: https://syzkaller.appspot.com/bug?id=50381fc73821ecae743b8cf24b4c9a04776f767c Reported-by: syzbot+a4087e40b9c13aad7892@syzkaller.appspotmail.com Fixes: 1e49a94cf707 ("exfat: add bitmap operations") Signed-off-by: Tadeusz Struk --- v2: - Use is_valid_cluster() helper to validate clu --- fs/exfat/balloc.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/fs/exfat/balloc.c b/fs/exfat/balloc.c index 03f142307174..92f5b5b5a0d0 100644 --- a/fs/exfat/balloc.c +++ b/fs/exfat/balloc.c @@ -149,6 +149,9 @@ int exfat_set_bitmap(struct inode *inode, unsigned int clu, bool sync) struct exfat_sb_info *sbi = EXFAT_SB(sb); WARN_ON(clu < EXFAT_FIRST_CLUSTER); + if (!is_valid_cluster(sbi, clu)) + return -EINVAL; + ent_idx = CLUSTER_TO_BITMAP_ENT(clu); i = BITMAP_OFFSET_SECTOR_INDEX(sb, ent_idx); b = BITMAP_OFFSET_BIT_IN_SECTOR(sb, ent_idx); @@ -167,6 +170,9 @@ void exfat_clear_bitmap(struct inode *inode, unsigned int clu, bool sync) struct exfat_mount_options *opts = &sbi->options; WARN_ON(clu < EXFAT_FIRST_CLUSTER); + if (!is_valid_cluster(sbi, clu)) + return; + ent_idx = CLUSTER_TO_BITMAP_ENT(clu); i = BITMAP_OFFSET_SECTOR_INDEX(sb, ent_idx); b = BITMAP_OFFSET_BIT_IN_SECTOR(sb, ent_idx); -- 2.36.1