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 752A12F90C5; Sat, 12 Sep 2026 18:45:29 +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=1789238730; cv=none; b=mP0hmKVdmSg4PGjLiWmgqzp5jEdCssh0DJ5D8qeWa6aI82HcVjNd4WbfcV6UvFOGIowyEo1q9OYQJFhPtRG5eQQZxqDmAoJE6EEHlgmVcgBjFM2zT2zoJPbGWLk8YjJyxDNn6Jlek1efHVAaczD1/264BPS+yegaIj6CDsmwy7s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789238730; c=relaxed/simple; bh=cPzKJ7qBipscs/+IPfY+9MniIfxPqH5CdPAHxOocT9Q=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=dkzhlcJA81w8ljxgPLcrdqUhFFrtdJOECcSl5jW0kPLyzqLzuoic9RUJrm58l7W1Chj+NpEkqeahhxqN+H3xYvQQsA2KW4vVqaodNz2BRnk1VTl2ui6VAQBAj0iROw8N4LezoPonIxCrKk+XFisJSuNDd4dK39Fj3gy5yZHNMBg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=bhODlos+; 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="bhODlos+" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 160991F000FF; Sat, 12 Sep 2026 18:45:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789238729; bh=Hdkjw4APRS507gIDJQcD4wjsAaJ2T9XaBD9FlTA//vo=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=bhODlos+SIaKrj0Kd7AmNe3Db/jmC5OVd1JyUH6e1v2csLvjjpM0tc6R5Alks+965 vtz5JWUVOLcD+fhyeX4C8byi9TPW7cRKFnlqOBH1k2tLQeiWZeeheOqwoMd0HecBCs 6hUFIdbtaQXh29nDohb70Hrnc6ITM0GKHzJ8BisA= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Bryam Vargas , Alison Schofield , Sasha Levin Subject: [PATCH 5.15 520/935] libnvdimm/labels: Bound the on-media label size before the shift Date: Sat, 12 Sep 2026 08:59:10 +0200 Message-ID: <20260912065538.751394139@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260912065526.833703348@linuxfoundation.org> References: <20260912065526.833703348@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 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Bryam Vargas [ Upstream commit 18f9124248ed7a9da1c31973b629dceef76a9b0c ] For a v1.2+ index, __nd_label_validate() computes the label size as 1 << (7 + nsindex[i]->labelsize), where labelsize is a u8 read from the label storage medium. A value of 25 or more makes the shift count reach or exceed the width of int -- undefined behavior -- and 24 already shifts into the sign bit. Only 0 (128-byte) and 1 (256-byte) are valid. Reject a labelsize above 1 before the shift. The result was rejected by the following size comparison anyway, so this only removes the undefined shift on a crafted or corrupted medium; conforming labels are unaffected. Fixes: 564e871aa66f ("libnvdimm, label: add v1.2 nvdimm label definitions") Signed-off-by: Bryam Vargas Reviewed-by: Alison Schofield Link: https://patch.msgid.link/20260624-b4-disp-d8279485-v3-2-cdb6cab28b41@proton.me Signed-off-by: Alison Schofield Signed-off-by: Sasha Levin --- drivers/nvdimm/label.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) diff --git a/drivers/nvdimm/label.c b/drivers/nvdimm/label.c index 148d45f570257..6c591fb03c066 100644 --- a/drivers/nvdimm/label.c +++ b/drivers/nvdimm/label.c @@ -137,10 +137,21 @@ static int __nd_label_validate(struct nvdimm_drvdata *ndd) /* label sizes larger than 128 arrived with v1.2 */ version = __le16_to_cpu(nsindex[i]->major) * 100 + __le16_to_cpu(nsindex[i]->minor); - if (version >= 102) + if (version >= 102) { + /* + * labelsize feeds the shift below; only 0 (128-byte) + * and 1 (256-byte) are valid -- a larger value would + * overflow or exceed the width of int. + */ + if (nsindex[i]->labelsize > 1) { + dev_dbg(dev, "nsindex%d labelsize: %d invalid\n", + i, nsindex[i]->labelsize); + continue; + } labelsize = 1 << (7 + nsindex[i]->labelsize); - else + } else { labelsize = 128; + } if (labelsize != sizeof_namespace_label(ndd)) { dev_dbg(dev, "nsindex%d labelsize %d invalid\n", -- 2.53.0