From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.14]) (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 7351131715E; Tue, 10 Mar 2026 17:53:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.14 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773165198; cv=none; b=TBYZBXiIYJq3QjfSsH7gTQy08jCpMOQYCIhgMQ0PmRPo5lvzOQl7RBE+v9B2Y2r2Prq9d83EIYrHVlofCwGD3ny3hWcGbyXzHNeT1JUc//Dx9hN3OgwBPW0flxhr0kugEwlIzAEVz0x4JplXv2luCjZWzhEtT944omLU8bNm9rw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773165198; c=relaxed/simple; bh=bwjFivXvDMR7ae/O+uHjEp3C9ypISb9Y3UZxG9mQKPI=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=MX8XiI+jINHpLS7SOultdPm8/XuJS3Q4x9wyM3CX/Br74+hU1l+Ri5LxrnTGXG7cbEmpglZN414kiCHSPhoJ4wNrIl/vhNeBe16vWFtI3mcaVSk5xbplJZ/Z4XAjMLtPTWvQNUt3LAiG6eqSMUizUPfBtPMm6fOv9Lf/IZx2Jpc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=fHN/N/u0; arc=none smtp.client-ip=198.175.65.14 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="fHN/N/u0" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1773165197; x=1804701197; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=bwjFivXvDMR7ae/O+uHjEp3C9ypISb9Y3UZxG9mQKPI=; b=fHN/N/u0hpQfdMBrTHqMKW75dMZvEd9pkyqSPGrd+qkPL+3kYvlW8yPk iRKRKpNE1SWhtQDHTpkLZPVjzIHt6zfZxgoLRDlXT8hRAbLdCvljIvUX8 ZM4ZSWqes3sOO0vfiPq3qIHzjVphuxi+8HVkRHbAqkCo9LTTJ9IhhWDxv s9qFKmxFD3Puuq5PU811Ju72oEtRUbKlXFQHOGR6NE8DbunFHz+3/8rvJ peehpU2ZtJX6aJFRovJo8GRtdg/iBZUqnleDGXgPkSwWkq95cIFRYjyN8 9UoMhMh6AG0fTv6DeaHMIW6HXWqcGF0vbZDWujvS1B6nqB5mbVOdny/fW A==; X-CSE-ConnectionGUID: AAeLKpf1RAa15DpFiLR1aA== X-CSE-MsgGUID: 0aHY/MW6RWSrFFNQ5Ac7KA== X-IronPort-AV: E=McAfee;i="6800,10657,11725"; a="78079707" X-IronPort-AV: E=Sophos;i="6.23,112,1770624000"; d="scan'208";a="78079707" Received: from fmviesa009.fm.intel.com ([10.60.135.149]) by orvoesa106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Mar 2026 10:53:14 -0700 X-CSE-ConnectionGUID: J8VruwUETZKm27QO2xN5rw== X-CSE-MsgGUID: CY9+hRJZTaSOxZmjDikjcw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.23,112,1770624000"; d="scan'208";a="215548388" Received: from aduenasd-mobl5.amr.corp.intel.com (HELO [10.125.110.11]) ([10.125.110.11]) by fmviesa009-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Mar 2026 10:53:12 -0700 Message-ID: <3b7f16d5-be31-42f9-9671-24532530273a@intel.com> Date: Tue, 10 Mar 2026 10:53:11 -0700 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 2/7] cxl/memdev: Hold memdev lock during memdev poison injection/clear To: Li Ming , Greg Kroah-Hartman , "Rafael J. Wysocki" , Danilo Krummrich , Davidlohr Bueso , Jonathan Cameron , Alison Schofield , Vishal Verma , Ira Weiny , Dan Williams , Bjorn Helgaas , Ben Cheatham Cc: driver-core@lists.linux.dev, linux-kernel@vger.kernel.org, linux-cxl@vger.kernel.org References: <20260310-fix_access_endpoint_without_drv_check-v1-0-94fe919a0b87@zohomail.com> <20260310-fix_access_endpoint_without_drv_check-v1-2-94fe919a0b87@zohomail.com> Content-Language: en-US From: Dave Jiang In-Reply-To: <20260310-fix_access_endpoint_without_drv_check-v1-2-94fe919a0b87@zohomail.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 3/10/26 8:57 AM, Li Ming wrote: > CXL memdev poison injection/clearing debugfs interfaces are visible > before the CXL memdev endpoint initialization, If user accesses the > interfaces before cxlmd->endpoint updated, it is possible to access an > invalid endpoint in cxl_dpa_to_region(). > > Hold CXL memdev lock at the beginning of the interfaces, this blocks the > interfaces until CXL memdev probing completed. > > The following patch will check the given endpoint validity in > cxl_dpa_to_region(). > > Suggested-by: Dan Williams > Signed-off-by: Li Ming Reviewed-by: Dave Jiang > --- > drivers/cxl/core/memdev.c | 10 ++++++++++ > 1 file changed, 10 insertions(+) > > diff --git a/drivers/cxl/core/memdev.c b/drivers/cxl/core/memdev.c > index 273c22118d3d..8ebaf9e96035 100644 > --- a/drivers/cxl/core/memdev.c > +++ b/drivers/cxl/core/memdev.c > @@ -295,6 +295,7 @@ int cxl_inject_poison_locked(struct cxl_memdev *cxlmd, u64 dpa) > if (!IS_ENABLED(CONFIG_DEBUG_FS)) > return 0; > > + device_lock_assert(&cxlmd->dev); > lockdep_assert_held(&cxl_rwsem.dpa); > lockdep_assert_held(&cxl_rwsem.region); > > @@ -331,6 +332,10 @@ int cxl_inject_poison(struct cxl_memdev *cxlmd, u64 dpa) > { > int rc; > > + ACQUIRE(device_intr, devlock)(&cxlmd->dev); > + if ((rc = ACQUIRE_ERR(device_intr, &devlock))) > + return rc; > + > ACQUIRE(rwsem_read_intr, region_rwsem)(&cxl_rwsem.region); > if ((rc = ACQUIRE_ERR(rwsem_read_intr, ®ion_rwsem))) > return rc; > @@ -355,6 +360,7 @@ int cxl_clear_poison_locked(struct cxl_memdev *cxlmd, u64 dpa) > if (!IS_ENABLED(CONFIG_DEBUG_FS)) > return 0; > > + device_lock_assert(&cxlmd->dev); > lockdep_assert_held(&cxl_rwsem.dpa); > lockdep_assert_held(&cxl_rwsem.region); > > @@ -400,6 +406,10 @@ int cxl_clear_poison(struct cxl_memdev *cxlmd, u64 dpa) > { > int rc; > > + ACQUIRE(device_intr, devlock)(&cxlmd->dev); > + if ((rc = ACQUIRE_ERR(device_intr, &devlock))) > + return rc; > + > ACQUIRE(rwsem_read_intr, region_rwsem)(&cxl_rwsem.region); > if ((rc = ACQUIRE_ERR(rwsem_read_intr, ®ion_rwsem))) > return rc; >