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 5014FC433F5 for ; Mon, 18 Apr 2022 17:39:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347169AbiDRRmY (ORCPT ); Mon, 18 Apr 2022 13:42:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58976 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233607AbiDRRmV (ORCPT ); Mon, 18 Apr 2022 13:42:21 -0400 Received: from mail-pl1-x62e.google.com (mail-pl1-x62e.google.com [IPv6:2607:f8b0:4864:20::62e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3292634668 for ; Mon, 18 Apr 2022 10:39:42 -0700 (PDT) Received: by mail-pl1-x62e.google.com with SMTP id d15so12885706pll.10 for ; Mon, 18 Apr 2022 10:39:42 -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:mime-version :content-transfer-encoding; bh=F/6jEswmwOAmnHJw/Z7NeFz92t2kSVNLzcVtS0Sf4kA=; b=RIdfh/Cx5VQRx41iMREwtJZLMcZj0gF41mm2ff3l/BFEvW8d773E2rDfXT6Zj+p18P wGUyW1kl9TUd9wp14H7XQTV/CR4M1q9fgf2giFEmt4e56IyhoHqQVKjEAtlo/Ha9mXey bbUNisaaxbYWoQgdxdq7vmNibfYgXZkBoib8/ZdspXWolt45K7+jg4RGzQoP9OYhGDKI KDhNbao0ELHEW2R/WXRIahnszeb/Y0B1PCwXWSa/Iv7W1VqpSs/J/2oDnrDFYwDcnVU1 LysHLHDVFf77gH3neJkj97FDN7mbJpKqrJt9Rb4IXWwK8g+ieNRJucPdnSjU/PlInR0c YXGw== 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=F/6jEswmwOAmnHJw/Z7NeFz92t2kSVNLzcVtS0Sf4kA=; b=pDNA/G13NLG/C0fG2ose6AUzk9v+iWPNMP+nDfj5nG7miGOUZE/R9OkXEXs+8dPvmt 0gSgt3TPEIOr1fDK5Lq46jNXw128HaogdSSwiS6YqiZDJdlL16EYitfy58hj5vZITJvE 7yGp5UH9IULSK8X3yV2zKhKlwFlml103opPp/t7NzWii3y4GnBewXaUJW6Ra6iE3lSRa dtI0r+6KkqHEGLpAS+BeBCbOHJYwRtthQePvgJOpSlkYlLx02RKDav9GkIfAYRMVM/tt NPPBbrMSy/VmhmR8LFRKcc0fIrZbd5jL+jqoq3/oAAFxxPrmdQruKkHJ8m+teEq/ANbu 9inw== X-Gm-Message-State: AOAM533g2FWI7BeAPMTCF/6sMChi3mw8wU/0jR5WaVtk4YszcVLeNpuX SqKXXlk3mkZM1elq4Hgt2N86yA== X-Google-Smtp-Source: ABdhPJx7X8qxRF/0CUmEkmDMmpwMka7fQnEnV5qlU+xAcna/NC7jX6aXDDXnHzq5S4ArvSDg2uZBFQ== X-Received: by 2002:a17:90b:17c6:b0:1d2:8450:49b3 with SMTP id me6-20020a17090b17c600b001d2845049b3mr8724918pjb.246.1650303581711; Mon, 18 Apr 2022 10:39:41 -0700 (PDT) Received: from localhost.localdomain ([50.39.160.154]) by smtp.gmail.com with ESMTPSA id x6-20020a17090a294600b001cba3274bd0sm17159326pjf.28.2022.04.18.10.39.41 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 18 Apr 2022 10:39:41 -0700 (PDT) From: Tadeusz Struk To: Namjae Jeon 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] exfat: check if cluster num is valid Date: Mon, 18 Apr 2022 10:39:23 -0700 Message-Id: <20220418173923.193173-1-tadeusz.struk@linaro.org> X-Mailer: git-send-email 2.35.1 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 truncate 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 --- fs/exfat/balloc.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/fs/exfat/balloc.c b/fs/exfat/balloc.c index 03f142307174..4ed81f86f993 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 (clu > EXFAT_DATA_CLUSTER_COUNT(sbi)) + 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 (clu > EXFAT_DATA_CLUSTER_COUNT(sbi)) + 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); -- 2.35.1