From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794404415; b=byPJNUHbK2kyRoqymizZd4wWJxYsEWxowtSQPVUw7BCDKetkRir48IXHwiOmOd/A6a1S m4/4RQD4lXl8cbGJapusD4LLUJG2uWOIrkiWZudQuKQdbNUIQZiMAuf3VdRAE9K3ox6mw HN6nF1TyQqg4dZ3Af902m86xB3roB69CDlz/MHECZlJA3vl9oZSjoJwO33FJ9StcsHuyT zN4nG4qqotpwW9AEcd5txTdrTbGy5vJCUdplU82DaYps3ImdhlAgeCJl0gvmh6y6tQE8n t83TWeKjqDUNAn+hcUbIwXZPqjzcSSJ2S9LlM1/jj1ItI9svGIK/ShhZ9be5TDwxx9A== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794404415; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:Content-Transfer-Encoding; bh=j+gWJ7ho/sGSsUoDu0vQA66UsbqPw8AgFsKSMNYuhuI=; b=VUfsHKgpScffXlanaNG6IRGDiwsHVJe8Piena3GxyRPCUdjBnpiSH6wqRwRRZuA+ZVQS RoSGwdfzrdnUrpCgeN2yo6mYhVjVo4wdQAvP3aMEDZBOblKn34/lMCChqlHtN1SMp/OpI D/rKEnuIRixa9wGLHcdiokFa3+ZbWEPv4hbN0QoGLIe6zM+YSh7js6YvRmhHL/MZycyls 7ByVtuQglExCyRmUya2LC1hC/jS24oamf01SNKAAskp1PHfGrlAA39oeRBmbLxWwZR74J 0aKEEzc18thF/Pt/TNURNpJHKFwxW7tUgpPsv5BI2ngN3anvz2SmOoXR3mFj1c8ubfw== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=ler96mqV; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3D053606A324 for ; Wed, 11 Nov 2026 13:40:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=ler96mqV Received: by smtp.kernel.org (Postfix) with ESMTPSA id E7BCC1F00A07; Wed, 11 Nov 2026 13:40:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794404414; bh=j+gWJ7ho/sGSsUoDu0vQA66UsbqPw8AgFsKSMNYuhuI=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=ler96mqVsfXOjlGroSxmCpBDoh9M/LBGPYBpcOeNlb1FGWGZUMJnIYCYqYM0vK5/M +pgCPG1/JejRh2pJdhPutZUvdBbaImqKbNQT/bOZbyqJPteKLQCli7nV7MNCWXGEbZ 1bsa3UUPlJ9cFSPhzjhbgX4MHlzarVYi+RaMqqGL2+rNHclQbFmidHj9Tz1eq7cjRM JOs0QQs1/budMr+L+5V4NAhtHntCdniJKf4rwHYTed+k/fEeOeIEWKvxXfnXYJdi2r yJ/J87fAiMWYjHHe95XROeA0OPCp6VhzSEmvcKqRU2WO+p150zs33eWftdx+0/9pjs YE0Hxj7oLwrTw== From: Sasha Levin To: stable@vger.kernel.org Cc: Giorgi Kobakhia , Andrew Morton , Xiang Mei , Joseph Qi , Mark Fasheh , Joel Becker , Sasha Levin Subject: [PATCH 6.18.y 2/2] ocfs2: fix array out of bound access in __ocfs2_find_path() Date: Wed, 11 Nov 2026 08:40:11 -0500 Message-ID: <20261111133959.1649406-2-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20261111133959.1649406-1-sashal@kernel.org> References: <20261107051119-failed-6.18-6193ce7896af@kernel.org> <20261111133959.1649406-1-sashal@kernel.org> X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Giorgi Kobakhia [ Upstream commit 6193ce7896afb52a321a0063c8b6a45e477a84e2 ] __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. Link: https://lore.kernel.org/20260922202159.2421642-1-gkobakhi@asu.edu Fixes: dcd0538ff4e8 ("ocfs2: sparse b-tree support") Signed-off-by: Giorgi Kobakhia Signed-off-by: Andrew Morton Tested-by: Xiang Mei Reviewed-by: Joseph Qi Assisted-by: LLM Cc: Mark Fasheh Cc: Joel Becker Cc: Signed-off-by: Sasha Levin --- 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 d35c6761dd124..27b8832d7820a 100644 --- a/fs/ocfs2/alloc.c +++ b/fs/ocfs2/alloc.c @@ -1796,6 +1796,7 @@ 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; @@ -1803,14 +1804,16 @@ 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" -- 2.53.0