From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out30-100.freemail.mail.aliyun.com (out30-100.freemail.mail.aliyun.com [115.124.30.100]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2AE5534C134; Wed, 23 Sep 2026 01:27:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=115.124.30.100 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790126878; cv=none; b=tS/+6AYUsn1TrJLGz219eolNHU/VeybcKro5rIj7mFJKzkoXPcbGSQf+uMp0YOYbUfVhBzSvPcP6gARvOogOAKQjvX32sjdLFS/Uq63wnZIEytc3lGFPDHHNO1U0LUDlSa6CzDzdhIyODm8HgYGGbAfrtN2CNkZbClbG6/zSJv0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790126878; c=relaxed/simple; bh=mW3Vkfkxjp+H+5FmxGrHaec7y+NgR5m7QC1Xm8DDNl0=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=YuWZv/3EivE0FeqYkeqgKCnUpgEaSnvc6tGljq2NrKfrVu8EKeXlACBrVaeOHRgCinsigW9E49ncFCoddKvX3X+giXC//RiyHwCEZksPAQDQz8FeGIcSNYu8r7hpXRaRpGKaTEObZ8ZbHSebr+G7sBR6C6oJqXSA+iWt/TH0+Mk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com; spf=pass smtp.mailfrom=linux.alibaba.com; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b=MenRviod; arc=none smtp.client-ip=115.124.30.100 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b="MenRviod" DKIM-Signature:v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1790126872; h=Message-ID:Date:MIME-Version:Subject:To:From:Content-Type; bh=cD1YZ/WyUkw2qCPI2vFSMU0Kjpp4BrTGZOfKp+4KDFA=; b=MenRviodAWpyhOyywxWe8gbb1EHKmmTfKjmXOyTxfs6GqaYywmHvMmrEOsVgYw0pYzdjtYO0Q+jgm6Cs40RFWIAyNKGN31sGrlPFhfRonOaT/dmuMCR53egmpjHmRhtBt2AD2HIM3LJceiYwSdu4A4WA++t/nOKq++iswDlcnU0= X-Alimail-AntiSpam:AC=PASS;BC=-1|-1;BR=01201311R171e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=maildocker-contentspam033032089153;MF=joseph.qi@linux.alibaba.com;NM=1;PH=DS;RN=8;SR=0;TI=SMTPD_---0XBVIAlL_1790126871; Received: from 30.170.56.46(mailfrom:joseph.qi@linux.alibaba.com fp:SMTPD_---0XBVIAlL_1790126871 cluster:ay36) by smtp.aliyun-inc.com; Wed, 23 Sep 2026 09:27:52 +0800 Message-ID: Date: Wed, 23 Sep 2026 09:27:51 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] ocfs2: fix array out of bound access in __ocfs2_find_path() To: Giorgi Kobakhia , Andrew Morton Cc: Mark Fasheh , Joel Becker , ocfs2-devel@lists.linux.dev, linux-kernel@vger.kernel.org, Xiang Mei , stable@vger.kernel.org References: <20260922202159.2421642-1-gkobakhi@asu.edu> From: Joseph Qi In-Reply-To: <20260922202159.2421642-1-gkobakhi@asu.edu> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 9/23/26 4:21 AM, Giorgi Kobakhia wrote: > __ocfs2_find_path() walks down the extent tree and records path by calling > find_path_ins(), which appends entry to path->p_node[]. It only has 5 > spots. > > A corrupted ocfs2 image whose extent block is pointing to itself causes > __ocfs2_find_path() descent endlessly, writing past the end of > path->p_node[] array. > > UBSAN: array-index-out-of-bounds in fs/ocfs2/alloc.c:677:14 > index 5 is out of range for type 'ocfs2_path_item [5]' > Call Trace: > > find_path_ins (fs/ocfs2/alloc.c:677 fs/ocfs2/alloc.c:1914) > __ocfs2_find_path.constprop.0 (fs/ocfs2/alloc.c:1882) > ocfs2_commit_truncate (fs/ocfs2/alloc.c:1924 fs/ocfs2/alloc.c:7286) > ocfs2_truncate_file (fs/ocfs2/file.c:515) > ocfs2_setattr (fs/ocfs2/file.c:1224) > notify_change (fs/attr.c:556) > do_truncate (fs/open.c:68) > do_ftruncate (fs/open.c:194 (discriminator 1)) > ksys_ftruncate (fs/open.c:206) > __x64_sys_ftruncate (fs/open.c:211 fs/open.c:209 fs/open.c:209) > > Commit a406aff8c051 ("ocfs2: validate l_tree_depth to avoid > out-of-bounds access") already restricts el->l_tree_depth to be less than > OCFS2_MAX_PATH_DEPTH, which is equal to 5. However, does not handle the > infinite descent case. > > Check if the el->l_tree_depth decreases on each descent. Maximum > descents are restricted to 4 and the path->p_node[] array does not > overflow. > > Fixes: dcd0538ff4e8 ("ocfs2: sparse b-tree support") > Cc: stable@vger.kernel.org > Assisted-by: LLM > Tested-by: Xiang Mei > Signed-off-by: Giorgi Kobakhia Looks fine. Reviewed-by: Joseph Qi > --- > fs/ocfs2/alloc.c | 9 ++++++--- > 1 file changed, 6 insertions(+), 3 deletions(-) > > diff --git a/fs/ocfs2/alloc.c b/fs/ocfs2/alloc.c > index be09e766ac1f..c85a472965d5 100644 > --- a/fs/ocfs2/alloc.c > +++ b/fs/ocfs2/alloc.c > @@ -1817,6 +1817,7 @@ static int __ocfs2_find_path(struct ocfs2_caching_info *ci, > int i, ret = 0; > u32 range; > u64 blkno; > + u32 prev_depth = OCFS2_MAX_PATH_DEPTH; > struct buffer_head *bh = NULL; > struct ocfs2_extent_block *eb; > struct ocfs2_extent_list *el; > @@ -1824,14 +1825,16 @@ static int __ocfs2_find_path(struct ocfs2_caching_info *ci, > > el = root_el; > while (el->l_tree_depth) { > - if (unlikely(le16_to_cpu(el->l_tree_depth) >= OCFS2_MAX_PATH_DEPTH)) { > + if (unlikely(le16_to_cpu(el->l_tree_depth) >= prev_depth)) { > ocfs2_error(ocfs2_metadata_cache_get_super(ci), > - "Owner %llu has invalid tree depth %u in extent list\n", > + "Owner %llu has invalid tree depth %u in extent list (max %u)\n", > (unsigned long long)ocfs2_metadata_cache_owner(ci), > - le16_to_cpu(el->l_tree_depth)); > + le16_to_cpu(el->l_tree_depth), prev_depth - 1); > ret = -EROFS; > goto out; > } > + prev_depth = le16_to_cpu(el->l_tree_depth); > + > if (!el->l_next_free_rec || !el->l_count) { > ocfs2_error(ocfs2_metadata_cache_get_super(ci), > "Owner %llu has empty extent list at depth %u\n"