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 266B751993D for ; Wed, 9 Sep 2026 10:34:29 +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=1788950070; cv=none; b=c0DqWMLWQZfaagwoiowcXvqyIcqW6sBh+s41XyrXZLsE6nCF1zg85TJNouO6s3mDY6/ONvpehtDRR81v1iQzbJ8so+pLPguaexzN3EYsU2WwRLqJBklmOn9IaNJz4gCw9Sk4HdLy417NbLzWtQUWz0dxZumm2mP7m/xVbaUjzUo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788950070; c=relaxed/simple; bh=5ldhAIaQV1Pnxwur81mZUPpnSuVYTe9IVlK+nvFSlY0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=kUDc9QmgdpIW2HHdw9M8zHsnzETu20rTh61uxrN5Zbmqv3u+oZ0/MysvRuu3nkuJIX3WUxt4b1Z9agpqQiQMLaIguy9vtw1UkYWaGI8irz+8i9KILGGo3O2MltcAH5sN4FtyMAMa3uwJDQuppMiBA9QbFoe2kkh/FSoK+5Z9wgQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=HxYTXLD4; 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="HxYTXLD4" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B4EC21F00A3E; Wed, 9 Sep 2026 10:34:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788950069; bh=zU7UMHXNDYVEpDPUuAnvuvk+CaQokY2g6CS0ZE9FhNM=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=HxYTXLD4TStn8vWilEBVEtCPslOM1EDyuJs4fZV2RgmRCfeKsXEa8lTirVZP28wMX taxYjMxW5TI2qSsIywKWCE+rYeDgSAGn9oQLwrAkweXUHF80Ifx8L1c9/5I04YLjoP qgYKE72P+a8zPMI4zB5k5iy765521mQqQRnB/ikYrXP37JRB9P1Gg4sZTY/qV7iX1l 4Hh1cr5VaHUNiDAsVD8qG+UPVPerNhyomWI8t1uOvJKDCwEZIRTChUUCOTR/HcGfOV q78v2lRe2MDpWKH1cB6FDMooyHmVyeilFyWsgrlkO6ex03zVs4MKyj+kCcoEUK4dki 8Wd05uDEf5ihA== 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 6.6.y 2/2] ocfs2: validate directory-index entry counts when reading metadata Date: Wed, 9 Sep 2026 06:34:24 -0400 Message-ID: <20260909103424.1543919-2-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260909103424.1543919-1-sashal@kernel.org> References: <2026090340-lecturer-unwashed-3c35@gregkh> <20260909103424.1543919-1-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 b706092c0c1b4..d9cd7b396c8eb 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