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 E5F613F23DB; Fri, 4 Sep 2026 05:19:45 +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=1788499187; cv=none; b=u1RCh5ID8UVoOj1gscSOzNZvJLUGA/ArrJxGVqih0Lo0Ud8/SvVMP9/dxHQvXugkQnfI0xIXCsud10jRNNouXNbfSrDk0YEm49O2HWKpDGbV0QzidnNC9PxdWCjjlNjBK1rCymS1xX+9wSVUl6LIk7MtJ4nen3eJ3AowULAEF7o= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788499187; c=relaxed/simple; bh=PsQMPy7rE7iCT1Q5EMoZ+NAjeo/dP2ZeBhUYGjiHbrk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ae52PNT6BEz8xTX2c+/xAhWaO1xD9T0UpAb8w3YE7XBFYsVO8SannKSf1zDJ0MgC5CMfYUfnLVp4iakCKV+G4OgftkYjAMomWPbBBU8HWT9fW+e0XezsDIObvaEPNPMeu7BR+3KrLlFF/2BiwfE00Q6r+TRQyQ2eWSg8D2/vpxE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=QipLekEB; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="QipLekEB" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0B8551F00A3D; Fri, 4 Sep 2026 05:19:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1788499185; bh=8CTsFbHuD5Rp0IqPfVv8G64UGz6ycLTBzRje9RJz/ak=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=QipLekEBvXnyPk3hxZf7CDjLI7dWKaLq/lkED9B2YqnU0zIufI8fKhCFGymT17y4I 7y7SP/lB/FQvz8JsUI4aNSJiEx1dsE1B93kbWQlBbje3T9yBiix7fM08gekSWU6xJ9 uG2jjVp8CZ1ajoQp6UxnbuAuBkQUayK3yVy+w8u0= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Ming-Hung Tsai , Bryam Vargas , Mikulas Patocka Subject: [PATCH 7.2 328/713] dm array: validate array block headers on read Date: Fri, 4 Sep 2026 06:54:56 +0200 Message-ID: <20260904045811.183450212@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260904045803.810145556@linuxfoundation.org> References: <20260904045803.810145556@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 7.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Bryam Vargas commit 2965787723084835b18dfe993cd450ebf5bd4540 upstream. array_block_check() validates blocknr and csum and nothing else, while node_check(), next to it, has bounded the structural fields since both were written. dm_array_cursor_next() takes its loop bound from the on-disk nr_entries and element_at() is unguarded pointer arithmetic, so a count larger than the block holds keeps the cursor in one block while the index grows past it and the read walks off the dm-bufio buffer -- dm_cache_load_mappings() drives it once per cache block at activation. Check the header against itself: reject a zero value_size, require max_entries to equal calc_max_entries() for that value_size and block size, and require nr_entries to fit. Equality rather than an upper bound, since a count below the real capacity trips BUG_ON() in fill_ablock() and trim_ablock(). Metadata dm-array writes satisfies all three. Fixes: 6513c29f44f2 ("dm persistent data: add transactional array") Suggested-by: Ming-Hung Tsai Cc: stable@vger.kernel.org Signed-off-by: Bryam Vargas Reviewed-by: Ming-Hung Tsai Signed-off-by: Mikulas Patocka Signed-off-by: Greg Kroah-Hartman --- drivers/md/persistent-data/dm-array.c | 37 ++++++++++++++++++++++++++-------- 1 file changed, 29 insertions(+), 8 deletions(-) --- a/drivers/md/persistent-data/dm-array.c +++ b/drivers/md/persistent-data/dm-array.c @@ -38,6 +38,14 @@ struct array_block { */ #define CSUM_XOR 595846735 +/* + * Each array block can hold this many values. + */ +static uint32_t calc_max_entries(size_t value_size, size_t size_of_block) +{ + return (size_of_block - sizeof(struct array_block)) / value_size; +} + static void array_block_prepare_for_write(const struct dm_block_validator *v, struct dm_block *b, size_t size_of_block) @@ -55,6 +63,7 @@ static int array_block_check(const struc size_t size_of_block) { struct array_block *bh_le = dm_block_data(b); + uint32_t nr_entries, max_entries, value_size; __le32 csum_disk; if (dm_block_location(b) != le64_to_cpu(bh_le->blocknr)) { @@ -74,6 +83,26 @@ static int array_block_check(const struc return -EILSEQ; } + nr_entries = le32_to_cpu(bh_le->nr_entries); + max_entries = le32_to_cpu(bh_le->max_entries); + value_size = le32_to_cpu(bh_le->value_size); + + if (!value_size) { + DMERR_LIMIT("%s failed: value_size is zero", __func__); + return -EILSEQ; + } + + if (max_entries != calc_max_entries(value_size, size_of_block)) { + DMERR_LIMIT("%s failed: max_entries %u invalid for value_size %u", + __func__, max_entries, value_size); + return -EILSEQ; + } + + if (nr_entries > max_entries) { + DMERR_LIMIT("%s failed: too many entries", __func__); + return -EILSEQ; + } + return 0; } @@ -139,14 +168,6 @@ static void dec_ablock_entries(struct dm } /* - * Each array block can hold this many values. - */ -static uint32_t calc_max_entries(size_t value_size, size_t size_of_block) -{ - return (size_of_block - sizeof(struct array_block)) / value_size; -} - -/* * Allocate a new array block. The caller will need to unlock block. */ static int alloc_ablock(struct dm_array_info *info, size_t size_of_block,