From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 A9B6B36EF35; Mon, 5 May 2025 22:57:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746485864; cv=none; b=Hky+ImWLXqVQpYoXC6OW73yZgAxelq/O0wD36WlmBy8iAw4u3z9vfTCjehwUrzq7vQBI6Y8fnfU1pwG7QF+PjfguILqBDV2evxYaG9bpUK29Y/d/y690Ns6FHKoi4ZF28rAr+EsWvqlWg7ai9UdC+hKSb+7AQah29z3P82PFgJM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746485864; c=relaxed/simple; bh=rRPQrr8rQ2U57aU/QceYFLpT/KG7abauUVPWd1WRWmc=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=AgoZ2jQNDWym9FGV4kd4ajdtpCXVHbOS4TL2ICfbDpWVbt8gsXDGZu1FMu+ccnKbo/3Rxt/hVJ2XzOX2lD5EhlzdmXmWPNa9NIP5A+FrkpLEDiWC8aJ/i4dJMBXmqi7EQHACf9viJtTk6xCH+RyY5DBXuXGD2ysSmZdipKLZqRU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=mMepZpEQ; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="mMepZpEQ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7D5F7C4CEE4; Mon, 5 May 2025 22:57:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1746485863; bh=rRPQrr8rQ2U57aU/QceYFLpT/KG7abauUVPWd1WRWmc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mMepZpEQVXXHb5ROzxLJbgP0xcq6KcodXDzqk6b41IUTPdD3YrikQvGVWcpzkcPW0 kVkPlUcAbwxJ7uGAHF+AFHd8qIGZ/gJgyaGxctAUhJXNDXTYMaWsnaMAGVM/kW0TGj AuuPTNtQAGkHsqtEiJdL1qcBKlWjwybfQq+QPMxyrO18cqh5rAQRWeQOfLJx0TkNML ZipYCfIFTvWHf8QYs8TZLI3unKcLY+udIRywKjkzGTSKmSnoBn/cVNhdMX0JT/Mnju Uxrjs+MKsqnsYMO9Icb1vxzTUnNxAw02oKmMrUh9cJr39mIw6uXXRRgtrEq4jn330o MLLZw6baLB2DA== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Robert Richter , Pankaj Gupta , Ira Weiny , Sasha Levin , dan.j.williams@intel.com, vishal.l.verma@intel.com, dave.jiang@intel.com, nvdimm@lists.linux.dev Subject: [PATCH AUTOSEL 6.6 036/294] libnvdimm/labels: Fix divide error in nd_label_data_init() Date: Mon, 5 May 2025 18:52:16 -0400 Message-Id: <20250505225634.2688578-36-sashal@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250505225634.2688578-1-sashal@kernel.org> References: <20250505225634.2688578-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.6.89 Content-Transfer-Encoding: 8bit From: Robert Richter [ Upstream commit ef1d3455bbc1922f94a91ed58d3d7db440652959 ] If a faulty CXL memory device returns a broken zero LSA size in its memory device information (Identify Memory Device (Opcode 4000h), CXL spec. 3.1, 8.2.9.9.1.1), a divide error occurs in the libnvdimm driver: Oops: divide error: 0000 [#1] PREEMPT SMP NOPTI RIP: 0010:nd_label_data_init+0x10e/0x800 [libnvdimm] Code and flow: 1) CXL Command 4000h returns LSA size = 0 2) config_size is assigned to zero LSA size (CXL pmem driver): drivers/cxl/pmem.c: .config_size = mds->lsa_size, 3) max_xfer is set to zero (nvdimm driver): drivers/nvdimm/label.c: max_xfer = min_t(size_t, ndd->nsarea.max_xfer, config_size); 4) A subsequent DIV_ROUND_UP() causes a division by zero: drivers/nvdimm/label.c: /* Make our initial read size a multiple of max_xfer size */ drivers/nvdimm/label.c: read_size = min(DIV_ROUND_UP(read_size, max_xfer) * max_xfer, drivers/nvdimm/label.c- config_size); Fix this by checking the config size parameter by extending an existing check. Signed-off-by: Robert Richter Reviewed-by: Pankaj Gupta Reviewed-by: Ira Weiny Link: https://patch.msgid.link/20250320112223.608320-1-rrichter@amd.com Signed-off-by: Ira Weiny Signed-off-by: Sasha Levin --- drivers/nvdimm/label.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/nvdimm/label.c b/drivers/nvdimm/label.c index 082253a3a9560..04f4a049599a1 100644 --- a/drivers/nvdimm/label.c +++ b/drivers/nvdimm/label.c @@ -442,7 +442,8 @@ int nd_label_data_init(struct nvdimm_drvdata *ndd) if (ndd->data) return 0; - if (ndd->nsarea.status || ndd->nsarea.max_xfer == 0) { + if (ndd->nsarea.status || ndd->nsarea.max_xfer == 0 || + ndd->nsarea.config_size == 0) { dev_dbg(ndd->dev, "failed to init config data area: (%u:%u)\n", ndd->nsarea.max_xfer, ndd->nsarea.config_size); return -ENXIO; -- 2.39.5