From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 956093EC2EF for ; Wed, 9 Sep 2026 10:19:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788949148; cv=none; b=IgEJdA5R+nuXk4xkHOKs4xTJhTp16xImN/9s/qdsiLfNWb/nXWGaVXEerzKDHuxIR1+fmNsypT5wDp8fLwkeAtyduOc8T+Uo1uKCDnFYRVpq9NYNs8IrX6pjEnmsIW48WUJFH24yKSMND+pnF6CSI8w5NCF82duqALAmwaqIY4k= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788949148; c=relaxed/simple; bh=Qr3NE9ZY/xWALwjo5H1IMuyvXa93YXzdtnhIB7aBZko=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Dc4VBkJ/ZQ4yNtnmhTsX62joQZapwjK4tUcvqXkITag08w8MLJi0vbpeWsdCrtbxu1106SDZVejdYaEG7NpKBaB6Jd5q/rtpBIc7M958UI9+Tp3kR+FpPDzOlZNz6hUmpSDKWmdgdvPICLcrjy6zi06xGIYW8HlptqbcRKzJqrc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=O8bghK3l; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="O8bghK3l" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 033BE1F00A3E; Wed, 9 Sep 2026 10:19:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788949147; bh=WGB8DA6VQNVoefmsgO9l3uNUieSpAXYhWMj2GIBH+JI=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=O8bghK3l/hvQ+U2Nko4Ev86Wog6cI7cWQaXmXLJxQptM2DntokLp0swMqwAe+CHMw EvQnoGehrUooNbe+pFbyq5fv5m29MurQODbmdFn9fD139g4i9vqjJobgYN9ZgQx/aJ cqZXJCNPuYoQRP0MVEacgD5AvHcbIAAIrBWnMi7uU8RqkRsvjvLvZoSIej2YSCkxqV 7ejvJYVMkioGFsbEPwILHLVTXSk3WlJ5LDYb0drerIc+K3v2p83pSR4agz+chsDGNg azwaLjzMzBgYo3stoqomnYBmAeeP0ozti/sq05OWs8LJD0Gt+mClkzur/PUn0/JIJp AuHwO2cux//jQ== From: Sasha Levin To: stable@vger.kernel.org Cc: Doruk Tan Ozturk , Joseph Qi , Joel Becker , Kees Cook , Mark Fasheh , Junxiao Bi , Changwei Ge , Jun Piao , Heming Zhao , Andrew Morton , Sasha Levin Subject: [PATCH 6.12.y 2/2] ocfs2: validate directory-index entry counts when reading metadata Date: Wed, 9 Sep 2026 06:19:03 -0400 Message-ID: <20260909101903.1491952-2-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260909101903.1491952-1-sashal@kernel.org> References: <2026090340-backside-dangling-fd8e@gregkh> <20260909101903.1491952-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Doruk Tan Ozturk [ Upstream commit bc70726ddad53c7e9a9a85915bf2415b0d4f42f9 ] ocfs2_validate_dx_leaf() and ocfs2_validate_dx_root() check the ECC and signature of an indexed-directory block before it reaches higher-level callers, but neither validator bounds the ocfs2_dx_entry_list counts against the capacity of the block that holds them. ocfs2_dx_dir_search() then walks for (i = 0; i < le16_to_cpu(entry_list->de_num_used); i++) dx_entry = &entry_list->de_entries[i]; over de_num_used entries with no bounds check. entry_list is either dx_leaf->dl_list (from ocfs2_read_dx_leaf) or, for an inline root, dx_root->dr_entries. A crafted on-disk image can set de_num_used (and de_count, which is the __counted_by_le() bound of de_entries) to 0xffff and make the walk read far past the end of the 4KB metadata block, giving a slab out-of-bounds read reachable from any path lookup, stat() or open() on an indexed directory once the image is mounted. Commit 775c17386a6f ("ocfs2: validate dx_root extent list fields during block read") already bounds dr_list for the non-inline dx_root, but left the inline dr_entries path and the dx_leaf dl_list unchecked. Add the same read-time validation for both entry lists: de_count must equal the capacity of the block (ocfs2_dx_entries_per_leaf()/per_root()) and de_num_used must not exceed de_count, rejecting corrupted metadata with -EFSCORRUPTED before ocfs2_dx_dir_search() can walk an out-of-range entry array. de_count is always written as exactly the block capacity when a leaf or inline root is formatted, so the equality check does not reject any valid image. Found by 0sec automated security-research tooling (https://0sec.ai). Link: https://lore.kernel.org/20260713205625.92391-1-doruk@0sec.ai Fixes: 9b7895efac90 ("ocfs2: Add a name indexed b-tree to directory inodes") Fixes: 4ed8a6bb083b ("ocfs2: Store dir index records inline") Assisted-by: 0sec:claude-opus-4-8 Signed-off-by: Doruk Tan Ozturk Reviewed-by: Joseph Qi Cc: Joel Becker Cc: Kees Cook Cc: Mark Fasheh Cc: Junxiao Bi Cc: Changwei Ge Cc: Jun Piao Cc: Heming Zhao Cc: Signed-off-by: Andrew Morton Signed-off-by: Sasha Levin --- fs/ocfs2/dir.c | 45 +++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 41 insertions(+), 4 deletions(-) diff --git a/fs/ocfs2/dir.c b/fs/ocfs2/dir.c index 6b9f6890c6090..dc1e379e58d50 100644 --- a/fs/ocfs2/dir.c +++ b/fs/ocfs2/dir.c @@ -611,6 +611,28 @@ static int ocfs2_validate_dx_root(struct super_block *sb, le16_to_cpu(el->l_count)); goto bail; } + } else { + struct ocfs2_dx_entry_list *dl_list = &dx_root->dr_entries; + + if (le16_to_cpu(dl_list->de_count) != + ocfs2_dx_entries_per_root(sb)) { + ret = ocfs2_error(sb, + "Dir Index Root # %llu has invalid de_count %u (expected %u)\n", + (unsigned long long)le64_to_cpu(dx_root->dr_blkno), + le16_to_cpu(dl_list->de_count), + ocfs2_dx_entries_per_root(sb)); + goto bail; + } + + if (le16_to_cpu(dl_list->de_num_used) > + le16_to_cpu(dl_list->de_count)) { + ret = ocfs2_error(sb, + "Dir Index Root # %llu has invalid de_num_used %u (de_count %u)\n", + (unsigned long long)le64_to_cpu(dx_root->dr_blkno), + le16_to_cpu(dl_list->de_num_used), + le16_to_cpu(dl_list->de_count)); + goto bail; + } } bail: @@ -650,10 +672,25 @@ static int ocfs2_validate_dx_leaf(struct super_block *sb, return ret; } - if (!OCFS2_IS_VALID_DX_LEAF(dx_leaf)) { - ret = ocfs2_error(sb, "Dir Index Leaf has bad signature %.*s\n", - 7, dx_leaf->dl_signature); - } + if (!OCFS2_IS_VALID_DX_LEAF(dx_leaf)) + return ocfs2_error(sb, "Dir Index Leaf has bad signature %.*s\n", + 7, dx_leaf->dl_signature); + + if (le16_to_cpu(dx_leaf->dl_list.de_count) != + ocfs2_dx_entries_per_leaf(sb)) + return ocfs2_error(sb, + "Dir Index Leaf # %llu has invalid de_count %u (expected %u)\n", + (unsigned long long)le64_to_cpu(dx_leaf->dl_blkno), + le16_to_cpu(dx_leaf->dl_list.de_count), + ocfs2_dx_entries_per_leaf(sb)); + + if (le16_to_cpu(dx_leaf->dl_list.de_num_used) > + le16_to_cpu(dx_leaf->dl_list.de_count)) + return ocfs2_error(sb, + "Dir Index Leaf # %llu has invalid de_num_used %u (de_count %u)\n", + (unsigned long long)le64_to_cpu(dx_leaf->dl_blkno), + le16_to_cpu(dx_leaf->dl_list.de_num_used), + le16_to_cpu(dx_leaf->dl_list.de_count)); return ret; } -- 2.53.0