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 27AE22777E3; Mon, 5 May 2025 22:41:03 +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=1746484864; cv=none; b=JCujk+YJ1TnpVuHSxhNGEEay13d8xLH2laPXrGDcBZ0q+xs+v32vCHblXyG1KSPLQIobXh12dvFbEHbMaPiF8JbMr02H8CtHStzxfh63l7Q8H43TUMjk6Frr6idks3BPMsBdTFXlKXvsNTlgr9gl7vKJfkSdmo3ET5W+AK70ILY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746484864; c=relaxed/simple; bh=rRPQrr8rQ2U57aU/QceYFLpT/KG7abauUVPWd1WRWmc=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=iRHgoVcOD8HCbeClIF9cpMDNMyEHKk5dZjsmg/x/PqOM0akFsMWD1klVO9cC+HFg3H5pQ/iBzPgyng0rajz864D/5BoVVTlVnGRR80y8C2SH6AJDh7ZrjixraHkEqFz6Z0fEnZnHT73SOeOQn6ywyQjKmcHPf02HGDQ9f2P8it4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=d4OwzBgj; 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="d4OwzBgj" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8C55AC4CEEE; Mon, 5 May 2025 22:41:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1746484863; bh=rRPQrr8rQ2U57aU/QceYFLpT/KG7abauUVPWd1WRWmc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=d4OwzBgjJVLD7d4Rw4yaVDN1w5um9U8fKpunl/y1g4vcI1uOAvg0v3/zUEC+9Dcoz OVuqqm67vg5Fu++PnGT28uAZMRp81I3Uj8RoKo2rdpZlsSUnYX871myrorY7uwDU9W U4absj31b35Pw4VI5dMu6PJaBk7qZIovwP9Z1BwxnZIbzWMwffabY5Z8icfyDmi2sr qAcXsgv05wL++HZctMO1cgNuVdCG68gDv03sWeQ1xuD7OwtKjUtcKYf2kD6DEWW5Tc 3oSOe8mxn+okeeM87x3ITG2uFXgtBKkHxsfmqXRNc1V/q/1WhECbQqUhmnC1v8FD/o sa5yEUsJwE/uw== 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 6.12 054/486] libnvdimm/labels: Fix divide error in nd_label_data_init() Date: Mon, 5 May 2025 18:32:10 -0400 Message-Id: <20250505223922.2682012-54-sashal@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250505223922.2682012-1-sashal@kernel.org> References: <20250505223922.2682012-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.12.26 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