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 AB36739B09F; Mon, 5 May 2025 23:14:01 +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=1746486842; cv=none; b=OU9r+n3nZqG5Q9GSW3yGeL3nuw8gQf3M2HKJNpMLbbAKOK9oJ2F0VBb8WJBDOzFno9TDXxANVuGLM0wtsW1ovxWNhk20jE7CYo0l0lb96jl0ohsWmfJwLNFXICUmD4RZh9NVi2sIo3OYaXa5UDdKQ16SBGPLkTCZ3r+C3VWiOr4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746486842; c=relaxed/simple; bh=NHmzvax4IPbiPdp1bDqYANZe/GMepCja/nvw2NzZI6k=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=leAYkubneIc8n9g+hLua48+ySqfEGgHq5nlBx5sGqlrfioZCxqB6SYQvJhpXCB6sn34orXuzfxTAVHDAB/yycn8kP1zRv0AWe+GpqDnm2wBYU5D7jNhFGl2sbB5Rgu529h3I1MPONI0TJOAnDwIUSKgcLKsCT8cBZlfDd8GzG+4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=sDdQRElh; 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="sDdQRElh" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7DEEFC4CEE4; Mon, 5 May 2025 23:14:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1746486841; bh=NHmzvax4IPbiPdp1bDqYANZe/GMepCja/nvw2NzZI6k=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=sDdQRElh3HR9Py76I6uncsgfg4GFgYSBvJfQRmXWlVpunrjRJjhNYkYY74EONReB6 +vBfJBEm94wAa0luMFDPHzuJ5HXCGdnSpmXi2ju9THLGnDXj8ttF5vtggH/Njihjxk lq1Cksvr267sePWQfzdvMeBAkzrqyqKkBFF2Upaq88cAY8TSbtVV2JGD83hmjn6u6G /GOsFd3MmEZEQBPf+joqwBCz9HO/zsrHsPV5JPlarvILc+dE83M/937ZcbwQGuwdst Z0Hqje2F8a03JqXYyTVli6MykiCDC7moAVsD0r1xImL4p5Oit3XeDlWNTM/ANBnSRT kjLsLr0z4oDxw== 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 5.15 019/153] libnvdimm/labels: Fix divide error in nd_label_data_init() Date: Mon, 5 May 2025 19:11:06 -0400 Message-Id: <20250505231320.2695319-19-sashal@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250505231320.2695319-1-sashal@kernel.org> References: <20250505231320.2695319-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: nvdimm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 5.15.181 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 7f473f9db300d..e1b511d09295f 100644 --- a/drivers/nvdimm/label.c +++ b/drivers/nvdimm/label.c @@ -437,7 +437,8 @@ 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