From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eu-smtp-delivery-151.mimecast.com (eu-smtp-delivery-151.mimecast.com [185.58.85.151]) (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 A2E828004F for ; Thu, 9 May 2024 21:07:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.58.85.151 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715288853; cv=none; b=OAJFnK/BwBKrgemnpdMmcT4lUGoewCXVNFNl06qy5sidm+lGyLAnAgEMChome6ortYvlDnlNqKZw1d6HdtZGchJRwZy8H+3GM0ZRQZTavQkKIR3Bx0Gv2VRD3T/GhUzmiGEe6AmmSUv4EFgwCOQYxkAhG8aHYJT8329ux7HhIwk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715288853; c=relaxed/simple; bh=goPKHQtoFbBJPMAI4x6He30hxH7vdSTb8jLbZxEZRIs=; h=From:To:CC:Subject:Date:Message-ID:References:In-Reply-To: MIME-Version:Content-Type; b=MGB2WcmPN7+qZy6Bg2FqBYPkE83VtqHIkomUjiW2Ogd+m19Xr2U84Z20EdGzVlnoDVcKrXiKN4xDqZf/U554Gl/zCuBPrAes6vYfXzikGCLeSc7YNgP/+OWMM2pgNC5SHapleMh2aZsWQ6Bs9BeZVyconeyhKpxy8GIK/UT/itI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=ACULAB.COM; spf=pass smtp.mailfrom=aculab.com; arc=none smtp.client-ip=185.58.85.151 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=ACULAB.COM Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=aculab.com Received: from AcuMS.aculab.com (156.67.243.121 [156.67.243.121]) by relay.mimecast.com with ESMTP with both STARTTLS and AUTH (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384) id uk-mta-174-MlsT2Si9P0yTWZ8FtgmvYw-1; Thu, 09 May 2024 22:07:23 +0100 X-MC-Unique: MlsT2Si9P0yTWZ8FtgmvYw-1 Received: from AcuMS.Aculab.com (10.202.163.4) by AcuMS.aculab.com (10.202.163.4) with Microsoft SMTP Server (TLS) id 15.0.1497.48; Thu, 9 May 2024 22:06:54 +0100 Received: from AcuMS.Aculab.com ([::1]) by AcuMS.aculab.com ([::1]) with mapi id 15.00.1497.048; Thu, 9 May 2024 22:06:54 +0100 From: David Laight To: 'Linus Torvalds' , Theodore Ts'o CC: Kees Cook , Justin Stitt , Peter Zijlstra , Mark Rutland , "linux-hardening@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "llvm@lists.linux.dev" Subject: RE: [RFC] Mitigating unexpected arithmetic overflow Thread-Topic: [RFC] Mitigating unexpected arithmetic overflow Thread-Index: AQHaoibwK91jQ1nmYEmzGISNIfAGlrGPY2nw Date: Thu, 9 May 2024 21:06:54 +0000 Message-ID: <5b37e8b1da534ebb8abc9b7b0f7022d2@AcuMS.aculab.com> References: <202404291502.612E0A10@keescook> <202405081144.D5FCC44A@keescook> <202405081354.B0A8194B3C@keescook> <202405081949.0565810E46@keescook> <20240509140854.GF3620298@mit.edu> In-Reply-To: Accept-Language: en-GB, en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-transport-fromentityheader: Hosted Precedence: bulk X-Mailing-List: llvm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: aculab.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: base64 Li4uDQo+IEdvaW5nIHRoZSBvdGhlciB3YXkgaXMgc2ltaWxhcjoNCj4gDQo+ICAgICAgICAgYWxs X2JpdHMgPSBsb3dfYml0cyArICgodTY0KSBoaWdoX2JpdHMgPDwgMTYpIDw8IDE2KTsNCj4gDQo+ IGFuZCBhZ2FpbiwgdGhlIGNvbXBpbGVyIHdpbGwgcmVjb2duaXplIHRoaXMgaWRpb20gYW5kIGRv IHRoZSByaWdodA0KPiB0aGluZyAoYW5kIGlmICdhbGxfYml0cycgaXMgb25seSAzMi1iaXQsIHRo ZSBjb21waWxlciB3aWxsIG9wdGltaXplDQo+IHRoZSBoaWdoIGJpdCBub2lzZSBhd2F5KS4NCg0K T24gYSAzMmJpdCBzeXN0ZW0gdGhlIGNvbXBpbGVyIG1pZ2h0IG5vdCBkbyB0aGUgZXhwZWN0ZWQg dGhpbmcuDQoNCkkgaGFkIHRlcnJpYmxlIHRyb3VibGUgd2l0aCB0aGUgMzJiaXQgZGl2X3U2NF91 MzIoKSBjb2RlIEkgd2FzDQpwbGF5aW5nIHdpdGggZ2V0dGluZyB0aGUgY29tcGlsZXIgdG8gZG8g J3NvbWV0aGluZyBzZW5zaWJsZScgZm9yDQp0aGF0Lg0KSSBqdXN0IGNvdWxkbid0IGdldCBpdCB0 byBzdG9wIGdlbmVyYXRpbmcgdHdvIDY0Yml0IHZhbHVlcw0KKGluIHR3byByZWdpc3RlciBwYWly cykgYW5kIHRoZW4gb3JpbmcgdGhlbSB0b2dldGhlci4NCkkgZGlkbid0IHRyeSB1c2luZyBhIHVu aW9uIC0gdGhhdCBtaWdodCB3b3JrLg0KT24geDY0IHRoZSBhc20gIkEiIChlZHg6ZWF4KSBhbmQg ImEiIGFuZCAiZCIgY29uc3RyYWludHMgd2lsbCBEVFJUDQpidXQgZm9yY2UgdGhlIHZhbHVlcyBp bnRvIGVkeDplYXggd2hpY2ggaXMgb2sgaWYgeW91IGFyZSBkb2luZyBkaXZpZGVzLg0KDQoJRGF2 aWQNCg0KLQ0KUmVnaXN0ZXJlZCBBZGRyZXNzIExha2VzaWRlLCBCcmFtbGV5IFJvYWQsIE1vdW50 IEZhcm0sIE1pbHRvbiBLZXluZXMsIE1LMSAxUFQsIFVLDQpSZWdpc3RyYXRpb24gTm86IDEzOTcz ODYgKFdhbGVzKQ0K