From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=192.198.163.11 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794195974; b=XbFXWA/2NH/9vnre6vyE2uPsuJH5fkbm8L564cwSl457wGl0AAujoFUPSuO9N1zNelnZ u/xaOo6VoGyNmNvLVSKGqDoxp3TyNpUacavjax9zub1PyItbGxdRlsugrPtN4YnPVU38O iMO0kkPyFXIijyVlrg2645YjPCp6GBWlHYGnvgUAmi4pD0I3GNRHB6L9zmdzbiXT4/KGo Rt3HWk6qAutfKe01RXfhojANDwK9lwJvSwDdZ2lXbcdiUpLEEY/vx26QFGumhak6TzmXc anfOREp7ReS5lZhfgHNlMwDDdqxlpF/mvHkAVnsJ2aEC9VxXJ1C5rEvkm2qFfF+HF2A== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794195974; h=DMARC-Filter:DKIM-Signature:X-CSE-ConnectionGUID:X-CSE-MsgGUID: X-IronPort-AV:X-IronPort-AV:Received:X-CSE-ConnectionGUID: X-CSE-MsgGUID:X-ExtLoop1:X-IronPort-AV:Received:Message-ID:Date: MIME-Version:User-Agent:Cc:Subject:To:References:Content-Language: From:In-Reply-To:Content-Type:Content-Transfer-Encoding; bh=gr96iaWliwZ75RhmyhCPwLKsIFpyS1bTKCZs7TpnfkY=; b=0MhpnjkcRaXL32d6yu8GUOiVtJrADuvEadOWD6G72DO/q/0Znho40x7pcXlrq236xskr 5sGsroPmeLAJzKg9TvGyt5NmgTWAiwmvS8Onyyls8q4qmen3J/Y76z5Nq3kUMkD/QuU8M fjb7gzBal0N2bYxY8kQfg0H1mRT78ZB18LK5Q/qTkT4X7HxBYz4t5eTtJFhbUD+zO31p0 66JctTPMXL6apeL18LVr5Lj8v3c64GfYoPNrWZW1+M1/Mlimjo7M7t1z1nIUE7MLRo9+G NCFKRx/MU94B9X+n3JdNfwwEUpqLsJUx5rJcyQ8wEwyO5bjyQiM5VzSVGPgoidYbEkw== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=linux.intel.com; spf=pass smtp.mailfrom=linux.intel.com; dkim=pass header.d=intel.com header.i=@intel.com header.a=rsa-sha256 header.s=Intel header.b=XSUo7BSD; arc=none smtp.remote-ip=192.198.163.11 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.11]) (using TLSv1.2 with cipher ECDHE-ECDSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E5930606A333 for ; Mon, 9 Nov 2026 03:46:12 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org E5930606A333 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=intel.com header.i=@intel.com header.a=rsa-sha256 header.s=Intel header.b=XSUo7BSD DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1794195973; x=1825731973; h=message-id:date:mime-version:cc:subject:to:references: from:in-reply-to:content-transfer-encoding; bh=BBS1gsXzLye4daje8OnhsCSPUgDhwifPpec/GQS7W5A=; b=XSUo7BSDnpWgClKL2F+WOhETkdGLHHWNcq8FmVChVfesoyk9ykLgoPSB NhTyG4xNOIJbZ+jXdwuA5VzMpVDVMk4GscOBfvVrCz2jAcdQxKeS0iQky mjSbWUbbMqOdA4Nmxp6dqY+RNbmDAW8akWE6KYQ6FFILsKLYUXZnNugGF yPj4BBhbwqRHWLssPeAeyNAym6ktzsyj7X5U4nxiGsklDu4+xfnII3cF4 vWNkI6bzGTJMPXqdvE3KCGLMwtjnjec28jAC8mqU9cuTqgTtYWOFGvlHa xJxtrFkYghHOjBwLcCjZEyM8bvgLMJ5Z5psrODnE9cR18y5zRxswjTm5b A==; X-CSE-ConnectionGUID: KNjxsySITEWuNpAziQ08ig== X-CSE-MsgGUID: gvFOV5/aQCa1xHdiJuO/uA== X-IronPort-AV: E=McAfee;i="6800,10657,11960"; a="2836534" X-IronPort-AV: E=Sophos;i="6.27,203,1787036400"; d="scan'208";a="2836534" Received: from orviesa005.jf.intel.com ([10.64.159.145]) by fmvoesa105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Nov 2026 19:46:12 -0800 X-CSE-ConnectionGUID: kX3MBr+NRvuhF+mtb/9uAw== X-CSE-MsgGUID: rTa4fatiTi+HSG1WxC2X9Q== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.27,203,1787036400"; d="scan'208";a="7658236" Received: from unknown (HELO [10.238.0.90]) ([10.238.0.90]) by smtpauth.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Nov 2026 19:46:10 -0800 Message-ID: <9d2bb2f7-4052-44fc-9ba6-a7ad6267678f@linux.intel.com> Date: Mon, 9 Nov 2026 11:46:07 +0800 X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Cc: baolu.lu@linux.intel.com, Will Deacon , Robin Murphy , Jean-Philippe Brucker , Yi Liu , iommu@lists.linux.dev, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3 5/5] iommu: Reject a same-domain replace in the attach handle APIs To: Nicolin Chen , joro@8bytes.org, Kevin Tian , Jason Gunthorpe References: <1b3a334eade93a5047d51af040f1400cd563189d.1793729087.git.nicolinc@nvidia.com> Content-Language: en-US From: Baolu Lu In-Reply-To: <1b3a334eade93a5047d51af040f1400cd563189d.1793729087.git.nicolinc@nvidia.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 11/4/2026 2:07 AM, Nicolin Chen wrote: > Both iommu_replace_group_handle() and iommu_replace_device_pasid() skip the > driver callback when the new domain is the one currently attached. In that > case, nothing flushes the pending faults that may still be holding the old > handle. Then, the caller frees the old handle once the replace returns, so > such a fault would hit a use-after-free. > > No caller does this today, since iommufd_device_do_replace() returns early > when the new hwpt is the old one. However, it is only a caller convention, > which neither API enforces. > > Reject a same-domain replace in both APIs with a WARN_ON, and document it > in their kernel-docs. > > Suggested-by: Lu Baolu > Reviewed-by: Yi Liu > Signed-off-by: Nicolin Chen > --- > drivers/iommu/iommu.c | 36 +++++++++++++++++++++++++++++------- > 1 file changed, 29 insertions(+), 7 deletions(-) Reviewed-by: Lu Baolu