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 029474A2A51 for ; Thu, 3 Sep 2026 14:14:49 +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=1788444897; cv=none; b=iXsw7Y28j1aiiZ9UMHCskp5QZ42xfcRUeOEprrDK6dOtFe7w6hkt9MHfJfyHFsyQCgqEYOibPHmknAQtSPthut1+L6Tjfi7lWT5kh044YL7IhG1GspKX3HmMQzqsmEfwxqN0OY46GQmz8H/G17KJMysTGaBEvj18GAqp4RdGLBA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788444897; c=relaxed/simple; bh=e6bxs/0pyJ5hc7ndPqdZDdoFixxbXNlX7lzaFWHPpP4=; h=Subject:To:Cc:From:Date:Message-ID:MIME-Version:Content-Type; b=In1kd1GfcDjZ0p5aL7nExPbLd5ZJ8bjWyZJ9u9a992ApTb6JCG2T6FgB8CFi/8asXq7c4pRyrciJyoWCt0SigvphLARL2HSfr6TStF7uqtsTZ+Qhm6yH1kleHWGHhPMDXvMRa1/LF1dGO/nPLqwGAFlwDECsYjrgcAK/eU2Idbs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Id748VPw; 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="Id748VPw" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5C56D1F00A3D; Thu, 3 Sep 2026 14:14:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1788444886; bh=eMJdjHpfVMz6eawURjQRbt3LLmQQ90pLqw3g7vxuBp0=; h=Subject:To:Cc:From:Date; b=Id748VPw1qOcXEj1d/ct+Z6gQJ1+bPu37Jpvj6rEIRHHDaWIyuF5RUzc7fNgIJN0f o4H5mqeU1jtCjtyWIjbloeKOwA5MDwhelLXEhU2eJKpw3kWY6uFF2ceI07tkfvKkkC 0fc2v6h2Wen37DcipopI3INLKVQLOLu3+zquheIk= Subject: FAILED: patch "[PATCH] dm array: validate array block headers on read" failed to apply to 5.15-stable tree To: hexlabsecurity@proton.me,mpatocka@redhat.com,mtsai@redhat.com Cc: From: Date: Thu, 03 Sep 2026 15:53:04 +0200 Message-ID: <2026090304-header-ideally-ce6b@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y git checkout FETCH_HEAD git cherry-pick -x 2965787723084835b18dfe993cd450ebf5bd4540 # git commit -s git send-email --to '' --in-reply-to '2026090304-header-ideally-ce6b@gregkh' --subject-prefix 'PATCH 5.15.y' 'HEAD^..' Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 2965787723084835b18dfe993cd450ebf5bd4540 Mon Sep 17 00:00:00 2001 From: Bryam Vargas Date: Fri, 31 Jul 2026 17:54:54 -0500 Subject: [PATCH] dm array: validate array block headers on read 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 diff --git a/drivers/md/persistent-data/dm-array.c b/drivers/md/persistent-data/dm-array.c index 8f8792e55806..7ba0a566f0ad 100644 --- 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 struct dm_block_validator *v, 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 struct dm_block_validator *v, 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; } @@ -138,14 +167,6 @@ static void dec_ablock_entries(struct dm_array_info *info, struct array_block *a on_entries(info, ab, vt->dec); } -/* - * 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. */