From mboxrd@z Thu Jan 1 00:00:00 1970 From: Walter Wu Subject: Re: [PATCH] kasan: fix the missing underflow in memmove and memcpy with CONFIG_KASAN_GENERIC=y Date: Thu, 3 Oct 2019 10:17:58 +0800 Message-ID: <1570069078.19702.57.camel@mtksdccf07> References: <20190927034338.15813-1-walter-zh.wu@mediatek.com> <1569594142.9045.24.camel@mtksdccf07> <1569818173.17361.19.camel@mtksdccf07> <1570018513.19702.36.camel@mtksdccf07> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: Dmitry Vyukov Cc: wsd_upstream , linux-mediatek@lists.infradead.org, LKML , kasan-dev , Linux-MM , Alexander Potapenko , Matthias Brugger , Andrey Ryabinin , Linux ARM List-Id: linux-mediatek@lists.infradead.org T24gV2VkLCAyMDE5LTEwLTAyIGF0IDE1OjU3ICswMjAwLCBEbWl0cnkgVnl1a292IHdyb3RlOgo+ IE9uIFdlZCwgT2N0IDIsIDIwMTkgYXQgMjoxNSBQTSBXYWx0ZXIgV3UgPHdhbHRlci16aC53dUBt ZWRpYXRlay5jb20+IHdyb3RlOgo+ID4KPiA+IE9uIE1vbiwgMjAxOS0wOS0zMCBhdCAxMjozNiAr MDgwMCwgV2FsdGVyIFd1IHdyb3RlOgo+ID4gPiBPbiBGcmksIDIwMTktMDktMjcgYXQgMjE6NDEg KzAyMDAsIERtaXRyeSBWeXVrb3Ygd3JvdGU6Cj4gPiA+ID4gT24gRnJpLCBTZXAgMjcsIDIwMTkg YXQgNDoyMiBQTSBXYWx0ZXIgV3UgPHdhbHRlci16aC53dUBtZWRpYXRlay5jb20+IHdyb3RlOgo+ ID4gPiA+ID4KPiA+ID4gPiA+IE9uIEZyaSwgMjAxOS0wOS0yNyBhdCAxNTowNyArMDIwMCwgRG1p dHJ5IFZ5dWtvdiB3cm90ZToKPiA+ID4gPiA+ID4gT24gRnJpLCBTZXAgMjcsIDIwMTkgYXQgNTo0 MyBBTSBXYWx0ZXIgV3UgPHdhbHRlci16aC53dUBtZWRpYXRlay5jb20+IHdyb3RlOgo+ID4gPiA+ ID4gPiA+Cj4gPiA+ID4gPiA+ID4gbWVtbW92ZSgpIGFuZCBtZW1jcHkoKSBoYXZlIG1pc3Npbmcg dW5kZXJmbG93IGlzc3Vlcy4KPiA+ID4gPiA+ID4gPiBXaGVuIC03IDw9IHNpemUgPCAwLCB0aGVu IEtBU0FOIHdpbGwgbWlzcyB0byBjYXRjaCB0aGUgdW5kZXJmbG93IGlzc3VlLgo+ID4gPiA+ID4g PiA+IEl0IGxvb2tzIGxpa2Ugc2hhZG93IHN0YXJ0IGFkZHJlc3MgYW5kIHNoYWRvdyBlbmQgYWRk cmVzcyBpcyB0aGUgc2FtZSwKPiA+ID4gPiA+ID4gPiBzbyBpdCBkb2VzIG5vdCBhY3R1YWxseSBj aGVjayBhbnl0aGluZy4KPiA+ID4gPiA+ID4gPgo+ID4gPiA+ID4gPiA+IFRoZSBmb2xsb3dpbmcg dGVzdCBpcyBpbmRlZWQgbm90IGNhdWdodCBieSBLQVNBTjoKPiA+ID4gPiA+ID4gPgo+ID4gPiA+ ID4gPiA+ICAgICAgICAgY2hhciAqcCA9IGttYWxsb2MoNjQsIEdGUF9LRVJORUwpOwo+ID4gPiA+ ID4gPiA+ICAgICAgICAgbWVtc2V0KChjaGFyICopcCwgMCwgNjQpOwo+ID4gPiA+ID4gPiA+ICAg ICAgICAgbWVtbW92ZSgoY2hhciAqKXAsIChjaGFyICopcCArIDQsIC0yKTsKPiA+ID4gPiA+ID4g PiAgICAgICAgIGtmcmVlKChjaGFyKilwKTsKPiA+ID4gPiA+ID4gPgo+ID4gPiA+ID4gPiA+IEl0 IHNob3VsZCBiZSBjaGVja2VkIGhlcmU6Cj4gPiA+ID4gPiA+ID4KPiA+ID4gPiA+ID4gPiB2b2lk ICptZW1tb3ZlKHZvaWQgKmRlc3QsIGNvbnN0IHZvaWQgKnNyYywgc2l6ZV90IGxlbikKPiA+ID4g PiA+ID4gPiB7Cj4gPiA+ID4gPiA+ID4gICAgICAgICBjaGVja19tZW1vcnlfcmVnaW9uKCh1bnNp Z25lZCBsb25nKXNyYywgbGVuLCBmYWxzZSwgX1JFVF9JUF8pOwo+ID4gPiA+ID4gPiA+ICAgICAg ICAgY2hlY2tfbWVtb3J5X3JlZ2lvbigodW5zaWduZWQgbG9uZylkZXN0LCBsZW4sIHRydWUsIF9S RVRfSVBfKTsKPiA+ID4gPiA+ID4gPgo+ID4gPiA+ID4gPiA+ICAgICAgICAgcmV0dXJuIF9fbWVt bW92ZShkZXN0LCBzcmMsIGxlbik7Cj4gPiA+ID4gPiA+ID4gfQo+ID4gPiA+ID4gPiA+Cj4gPiA+ ID4gPiA+ID4gV2UgZml4IHRoZSBzaGFkb3cgZW5kIGFkZHJlc3Mgd2hpY2ggaXMgY2FsY3VsYXRl ZCwgdGhlbiBnZW5lcmljIEtBU0FOCj4gPiA+ID4gPiA+ID4gZ2V0IHRoZSByaWdodCBzaGFkb3cg ZW5kIGFkZHJlc3MgYW5kIGRldGVjdCB0aGlzIHVuZGVyZmxvdyBpc3N1ZS4KPiA+ID4gPiA+ID4g Pgo+ID4gPiA+ID4gPiA+IFsxXSBodHRwczovL2J1Z3ppbGxhLmtlcm5lbC5vcmcvc2hvd19idWcu Y2dpP2lkPTE5OTM0MQo+ID4gPiA+ID4gPiA+Cj4gPiA+ID4gPiA+ID4gU2lnbmVkLW9mZi1ieTog V2FsdGVyIFd1IDx3YWx0ZXItemgud3VAbWVkaWF0ZWsuY29tPgo+ID4gPiA+ID4gPiA+IFJlcG9y dGVkLWJ5OiBEbWl0cnkgVnl1a292IDxkdnl1a292QGdvb2dsZS5jb20+Cj4gPiA+ID4gPiA+ID4g LS0tCj4gPiA+ID4gPiA+ID4gIGxpYi90ZXN0X2thc2FuLmMgICB8IDM2ICsrKysrKysrKysrKysr KysrKysrKysrKysrKysrKysrKysrKwo+ID4gPiA+ID4gPiA+ICBtbS9rYXNhbi9nZW5lcmljLmMg fCAgOCArKysrKystLQo+ID4gPiA+ID4gPiA+ICAyIGZpbGVzIGNoYW5nZWQsIDQyIGluc2VydGlv bnMoKyksIDIgZGVsZXRpb25zKC0pCj4gPiA+ID4gPiA+ID4KPiA+ID4gPiA+ID4gPiBkaWZmIC0t Z2l0IGEvbGliL3Rlc3Rfa2FzYW4uYyBiL2xpYi90ZXN0X2thc2FuLmMKPiA+ID4gPiA+ID4gPiBp bmRleCBiNjNiMzY3YTk0ZTguLjhiZDAxNDg1MjU1NiAxMDA2NDQKPiA+ID4gPiA+ID4gPiAtLS0g YS9saWIvdGVzdF9rYXNhbi5jCj4gPiA+ID4gPiA+ID4gKysrIGIvbGliL3Rlc3Rfa2FzYW4uYwo+ ID4gPiA+ID4gPiA+IEBAIC0yODAsNiArMjgwLDQwIEBAIHN0YXRpYyBub2lubGluZSB2b2lkIF9f aW5pdCBrbWFsbG9jX29vYl9pbl9tZW1zZXQodm9pZCkKPiA+ID4gPiA+ID4gPiAgICAgICAgIGtm cmVlKHB0cik7Cj4gPiA+ID4gPiA+ID4gIH0KPiA+ID4gPiA+ID4gPgo+ID4gPiA+ID4gPiA+ICtz dGF0aWMgbm9pbmxpbmUgdm9pZCBfX2luaXQga21hbGxvY19vb2JfaW5fbWVtbW92ZV91bmRlcmZs b3codm9pZCkKPiA+ID4gPiA+ID4gPiArewo+ID4gPiA+ID4gPiA+ICsgICAgICAgY2hhciAqcHRy Owo+ID4gPiA+ID4gPiA+ICsgICAgICAgc2l6ZV90IHNpemUgPSA2NDsKPiA+ID4gPiA+ID4gPiAr Cj4gPiA+ID4gPiA+ID4gKyAgICAgICBwcl9pbmZvKCJ1bmRlcmZsb3cgb3V0LW9mLWJvdW5kcyBp biBtZW1tb3ZlXG4iKTsKPiA+ID4gPiA+ID4gPiArICAgICAgIHB0ciA9IGttYWxsb2Moc2l6ZSwg R0ZQX0tFUk5FTCk7Cj4gPiA+ID4gPiA+ID4gKyAgICAgICBpZiAoIXB0cikgewo+ID4gPiA+ID4g PiA+ICsgICAgICAgICAgICAgICBwcl9lcnIoIkFsbG9jYXRpb24gZmFpbGVkXG4iKTsKPiA+ID4g PiA+ID4gPiArICAgICAgICAgICAgICAgcmV0dXJuOwo+ID4gPiA+ID4gPiA+ICsgICAgICAgfQo+ ID4gPiA+ID4gPiA+ICsKPiA+ID4gPiA+ID4gPiArICAgICAgIG1lbXNldCgoY2hhciAqKXB0ciwg MCwgNjQpOwo+ID4gPiA+ID4gPiA+ICsgICAgICAgbWVtbW92ZSgoY2hhciAqKXB0ciwgKGNoYXIg KilwdHIgKyA0LCAtMik7Cj4gPiA+ID4gPiA+ID4gKyAgICAgICBrZnJlZShwdHIpOwo+ID4gPiA+ ID4gPiA+ICt9Cj4gPiA+ID4gPiA+ID4gKwo+ID4gPiA+ID4gPiA+ICtzdGF0aWMgbm9pbmxpbmUg dm9pZCBfX2luaXQga21hbGxvY19vb2JfaW5fbWVtbW92ZV9vdmVyZmxvdyh2b2lkKQo+ID4gPiA+ ID4gPiA+ICt7Cj4gPiA+ID4gPiA+ID4gKyAgICAgICBjaGFyICpwdHI7Cj4gPiA+ID4gPiA+ID4g KyAgICAgICBzaXplX3Qgc2l6ZSA9IDY0Owo+ID4gPiA+ID4gPiA+ICsKPiA+ID4gPiA+ID4gPiAr ICAgICAgIHByX2luZm8oIm92ZXJmbG93IG91dC1vZi1ib3VuZHMgaW4gbWVtbW92ZVxuIik7Cj4g PiA+ID4gPiA+ID4gKyAgICAgICBwdHIgPSBrbWFsbG9jKHNpemUsIEdGUF9LRVJORUwpOwo+ID4g PiA+ID4gPiA+ICsgICAgICAgaWYgKCFwdHIpIHsKPiA+ID4gPiA+ID4gPiArICAgICAgICAgICAg ICAgcHJfZXJyKCJBbGxvY2F0aW9uIGZhaWxlZFxuIik7Cj4gPiA+ID4gPiA+ID4gKyAgICAgICAg ICAgICAgIHJldHVybjsKPiA+ID4gPiA+ID4gPiArICAgICAgIH0KPiA+ID4gPiA+ID4gPiArCj4g PiA+ID4gPiA+ID4gKyAgICAgICBtZW1zZXQoKGNoYXIgKilwdHIsIDAsIDY0KTsKPiA+ID4gPiA+ ID4gPiArICAgICAgIG1lbW1vdmUoKGNoYXIgKilwdHIgKyBzaXplLCAoY2hhciAqKXB0ciwgMik7 Cj4gPiA+ID4gPiA+ID4gKyAgICAgICBrZnJlZShwdHIpOwo+ID4gPiA+ID4gPiA+ICt9Cj4gPiA+ ID4gPiA+ID4gKwo+ID4gPiA+ID4gPiA+ICBzdGF0aWMgbm9pbmxpbmUgdm9pZCBfX2luaXQga21h bGxvY191YWYodm9pZCkKPiA+ID4gPiA+ID4gPiAgewo+ID4gPiA+ID4gPiA+ICAgICAgICAgY2hh ciAqcHRyOwo+ID4gPiA+ID4gPiA+IEBAIC03MzQsNiArNzY4LDggQEAgc3RhdGljIGludCBfX2lu aXQga21hbGxvY190ZXN0c19pbml0KHZvaWQpCj4gPiA+ID4gPiA+ID4gICAgICAgICBrbWFsbG9j X29vYl9tZW1zZXRfNCgpOwo+ID4gPiA+ID4gPiA+ICAgICAgICAga21hbGxvY19vb2JfbWVtc2V0 XzgoKTsKPiA+ID4gPiA+ID4gPiAgICAgICAgIGttYWxsb2Nfb29iX21lbXNldF8xNigpOwo+ID4g PiA+ID4gPiA+ICsgICAgICAga21hbGxvY19vb2JfaW5fbWVtbW92ZV91bmRlcmZsb3coKTsKPiA+ ID4gPiA+ID4gPiArICAgICAgIGttYWxsb2Nfb29iX2luX21lbW1vdmVfb3ZlcmZsb3coKTsKPiA+ ID4gPiA+ID4gPiAgICAgICAgIGttYWxsb2NfdWFmKCk7Cj4gPiA+ID4gPiA+ID4gICAgICAgICBr bWFsbG9jX3VhZl9tZW1zZXQoKTsKPiA+ID4gPiA+ID4gPiAgICAgICAgIGttYWxsb2NfdWFmMigp Owo+ID4gPiA+ID4gPiA+IGRpZmYgLS1naXQgYS9tbS9rYXNhbi9nZW5lcmljLmMgYi9tbS9rYXNh bi9nZW5lcmljLmMKPiA+ID4gPiA+ID4gPiBpbmRleCA2MTZmOWRkODJkMTIuLjM0Y2EyM2Q1OWU2 NyAxMDA2NDQKPiA+ID4gPiA+ID4gPiAtLS0gYS9tbS9rYXNhbi9nZW5lcmljLmMKPiA+ID4gPiA+ ID4gPiArKysgYi9tbS9rYXNhbi9nZW5lcmljLmMKPiA+ID4gPiA+ID4gPiBAQCAtMTMxLDkgKzEz MSwxMyBAQCBzdGF0aWMgX19hbHdheXNfaW5saW5lIGJvb2wgbWVtb3J5X2lzX3BvaXNvbmVkX24o dW5zaWduZWQgbG9uZyBhZGRyLAo+ID4gPiA+ID4gPiA+ICAgICAgICAgICAgICAgICAgICAgICAg ICAgICAgICAgICAgICAgICAgICAgICAgIHNpemVfdCBzaXplKQo+ID4gPiA+ID4gPiA+ICB7Cj4g PiA+ID4gPiA+ID4gICAgICAgICB1bnNpZ25lZCBsb25nIHJldDsKPiA+ID4gPiA+ID4gPiArICAg ICAgIHZvaWQgKnNoYWRvd19zdGFydCA9IGthc2FuX21lbV90b19zaGFkb3coKHZvaWQgKilhZGRy KTsKPiA+ID4gPiA+ID4gPiArICAgICAgIHZvaWQgKnNoYWRvd19lbmQgPSBrYXNhbl9tZW1fdG9f c2hhZG93KCh2b2lkICopYWRkciArIHNpemUgLSAxKSArIDE7Cj4gPiA+ID4gPiA+ID4KPiA+ID4g PiA+ID4gPiAtICAgICAgIHJldCA9IG1lbW9yeV9pc19ub256ZXJvKGthc2FuX21lbV90b19zaGFk b3coKHZvaWQgKilhZGRyKSwKPiA+ID4gPiA+ID4gPiAtICAgICAgICAgICAgICAgICAgICAgICBr YXNhbl9tZW1fdG9fc2hhZG93KCh2b2lkICopYWRkciArIHNpemUgLSAxKSArIDEpOwo+ID4gPiA+ ID4gPiA+ICsgICAgICAgaWYgKChsb25nKXNpemUgPCAwKQo+ID4gPiA+ID4gPiA+ICsgICAgICAg ICAgICAgICBzaGFkb3dfZW5kID0ga2FzYW5fbWVtX3RvX3NoYWRvdygodm9pZCAqKWFkZHIgKyBz aXplKTsKPiA+ID4gPiA+ID4KPiA+ID4gPiA+ID4gSGkgV2FsdGVyLAo+ID4gPiA+ID4gPgo+ID4g PiA+ID4gPiBUaGFua3MgZm9yIHdvcmtpbmcgb24gdGhpcy4KPiA+ID4gPiA+ID4KPiA+ID4gPiA+ ID4gSWYgc2l6ZTwwLCBkb2VzIGl0IG1ha2Ugc2Vuc2UgdG8gY29udGludWUgYXQgYWxsPyBXZSB3 aWxsIHN0aWxsIGNoZWNrCj4gPiA+ID4gPiA+IDFQQiBvZiBzaGFkb3cgbWVtb3J5PyBXaGF0IGhh cHBlbnMgd2hlbiB3ZSBwYXNzIHN1Y2ggaHVnZSByYW5nZSB0bwo+ID4gPiA+ID4gPiBtZW1vcnlf aXNfbm9uemVybz8KPiA+ID4gPiA+ID4gUGVyaGFwcyBpdCdzIGJldHRlciB0byBwcm9kdWNlIGFu IGVycm9yIGFuZCBiYWlsIG91dCBpbW1lZGlhdGVseSBpZiBzaXplPDA/Cj4gPiA+ID4gPgo+ID4g PiA+ID4gSSBhZ3JlZSB3aXRoIHdoYXQgeW91IHNhaWQuIHdoZW4gc2l6ZTwwLCBpdCBpcyBpbmRl ZWQgYW4gdW5yZWFzb25hYmxlCj4gPiA+ID4gPiBiZWhhdmlvciwgaXQgc2hvdWxkIGJlIGJsb2Nr ZWQgZnJvbSBjb250aW51aW5nIHRvIGRvLgo+ID4gPiA+ID4KPiA+ID4gPiA+Cj4gPiA+ID4gPiA+ IEFsc28sIHdoYXQncyB0aGUgZmFpbHVyZSBtb2RlIG9mIHRoZSB0ZXN0cz8gRGlkbid0IHRoZXkg YmFkbHkgY29ycnVwdAo+ID4gPiA+ID4gPiBtZW1vcnk/IFdlIHRyaWVkIHRvIGtlZXAgdGVzdHMg c3VjaCB0aGF0IHRoZXkgcHJvZHVjZSB0aGUgS0FTQU4KPiA+ID4gPiA+ID4gcmVwb3J0cywgYnV0 IGRvbid0IGJhZGx5IGNvcnJ1cHQgbWVtb3J5IGIvYy8gd2UgbmVlZCB0byBydW4gYWxsIG9mCj4g PiA+ID4gPiA+IHRoZW0uCj4gPiA+ID4gPgo+ID4gPiA+ID4gTWF5YmUgd2Ugc2hvdWxkIGZpcnN0 IHByb2R1Y2UgS0FTQU4gcmVwb3J0cyBhbmQgdGhlbiBnbyB0byBleGVjdXRlCj4gPiA+ID4gPiBt ZW1tb3ZlKCkgb3IgZG8gbm90aGluZz8gSXQgbG9va3MgbGlrZSBpdOKAmXMgZG9pbmcgdGhlIGZv bGxvd2luZy5vcj8KPiA+ID4gPiA+Cj4gPiA+ID4gPiB2b2lkICptZW1tb3ZlKHZvaWQgKmRlc3Qs IGNvbnN0IHZvaWQgKnNyYywgc2l6ZV90IGxlbikKPiA+ID4gPiA+ICB7Cj4gPiA+ID4gPiArICAg ICAgIGlmIChsb25nKGxlbikgPD0gMCkKPiA+ID4gPgo+ID4gPiA+IC9cL1wvXC9cL1wvXAo+ID4g PiA+Cj4gPiA+ID4gVGhpcyBjaGVjayBuZWVkcyB0byBiZSBpbnNpZGUgb2YgY2hlY2tfbWVtb3J5 X3JlZ2lvbiwgb3RoZXJ3aXNlIHdlCj4gPiA+ID4gd2lsbCBoYXZlIHNpbWlsYXIgcHJvYmxlbXMg aW4gYWxsIG90aGVyIHBsYWNlcyB0aGF0IHVzZQo+ID4gPiA+IGNoZWNrX21lbW9yeV9yZWdpb24u Cj4gPiA+IFRoYW5rcyBmb3IgeW91ciByZW1pbmRlci4KPiA+ID4KPiA+ID4gIGJvb2wgY2hlY2tf bWVtb3J5X3JlZ2lvbih1bnNpZ25lZCBsb25nIGFkZHIsIHNpemVfdCBzaXplLCBib29sIHdyaXRl LAo+ID4gPiAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgIHVuc2lnbmVkIGxvbmcgcmV0 X2lwKQo+ID4gPiAgewo+ID4gPiArICAgICAgIGlmIChsb25nKHNpemUpIDwgMCkgewo+ID4gPiAr ICAgICAgICAgICAgICAga2FzYW5fcmVwb3J0X2ludmFsaWRfc2l6ZShzcmMsIGRlc3QsIGxlbiwg X1JFVF9JUF8pOwo+ID4gPiArICAgICAgICAgICAgICAgcmV0dXJuIGZhbHNlOwo+ID4gPiArICAg ICAgIH0KPiA+ID4gKwo+ID4gPiAgICAgICAgIHJldHVybiBjaGVja19tZW1vcnlfcmVnaW9uX2lu bGluZShhZGRyLCBzaXplLCB3cml0ZSwgcmV0X2lwKTsKPiA+ID4gIH0KPiA+ID4KPiA+ID4gPiBC dXQgY2hlY2tfbWVtb3J5X3JlZ2lvbiBhbHJlYWR5IHJldHVybnMgYSBib29sLCBzbyB3ZSBjb3Vs ZCBjaGVjayB0aGF0Cj4gPiA+ID4gYm9vbCBhbmQgcmV0dXJuIGVhcmx5Lgo+ID4gPgo+ID4gPiBX aGVuIHNpemU8MCwgd2Ugc2hvdWxkIG9ubHkgc2hvdyBvbmUgS0FTQU4gcmVwb3J0LCBhbmQgc2hv dWxkIHdlIG9ubHkKPiA+ID4gbGltaXQgdG8gcmV0dXJuIHdoZW4gc2l6ZTwwIGlzIHRydWU/IElm IHlzZSwgdGhlbiBfX21lbW1vdmUoKSB3aWxsIGRvCj4gPiA+IG5vdGhpbmcuCj4gPiA+Cj4gPiA+ Cj4gPiA+ICB2b2lkICptZW1tb3ZlKHZvaWQgKmRlc3QsIGNvbnN0IHZvaWQgKnNyYywgc2l6ZV90 IGxlbikKPiA+ID4gIHsKPiA+ID4gLSAgICAgICBjaGVja19tZW1vcnlfcmVnaW9uKCh1bnNpZ25l ZCBsb25nKXNyYywgbGVuLCBmYWxzZSwgX1JFVF9JUF8pOwo+ID4gPiArICAgICAgIGlmKCFjaGVj a19tZW1vcnlfcmVnaW9uKCh1bnNpZ25lZCBsb25nKXNyYywgbGVuLCBmYWxzZSwKPiA+ID4gX1JF VF9JUF8pCj4gPiA+ICsgICAgICAgICAgICAgICAmJiBsb25nKHNpemUpIDwgMCkKPiA+ID4gKyAg ICAgICAgICAgICAgIHJldHVybjsKPiA+ID4gKwo+ID4gPiAgICAgICAgIGNoZWNrX21lbW9yeV9y ZWdpb24oKHVuc2lnbmVkIGxvbmcpZGVzdCwgbGVuLCB0cnVlLCBfUkVUX0lQXyk7Cj4gPiA+Cj4g PiA+ICAgICAgICAgcmV0dXJuIF9fbWVtbW92ZShkZXN0LCBzcmMsIGxlbik7Cj4gPiA+Cj4gPiA+ ID4KPiA+IEhpIERtaXRyeSwKPiA+Cj4gPiBXaGF0IGRvIHlvdSB0aGluayB0aGUgZm9sbG93aW5n IGNvZGUgaXMgYmV0dGVyIHRoYW4gdGhlIGFib3ZlIG9uZS4KPiA+IEluIG1lbW1tb3ZlL21lbXNl dC9tZW1jcHksIHRoZXkgbmVlZCB0byBkZXRlcm1pbmUgd2hldGhlciBzaXplIDwgMCBpcwo+ID4g dHJ1ZS4gd2UgZGlyZWN0bHkgZGV0ZXJtaW5lIHdoZXRoZXIgc2l6ZSBpcyBuZWdhdGl2ZSBpbiBt ZW1tb3ZlIGFuZAo+ID4gcmV0dXJuIGVhcmx5LiBpdCBhdm9pZCB0byBnZW5lcmF0ZSByZXBlYXRl ZCBLQVNBTiByZXBvcnQuIElzIGl0IGJldHRlcj8KPiA+Cj4gPiB2b2lkICptZW1tb3ZlKHZvaWQg KmRlc3QsIGNvbnN0IHZvaWQgKnNyYywgc2l6ZV90IGxlbikKPiA+IHsKPiA+ICsgICAgICAgaWYg KGxvbmcoc2l6ZSkgPCAwKSB7Cj4gPiArICAgICAgICAgICAgICAga2FzYW5fcmVwb3J0X2ludmFs aWRfc2l6ZShzcmMsIGRlc3QsIGxlbiwgX1JFVF9JUF8pOwo+ID4gKyAgICAgICAgICAgICAgIHJl dHVybjsKPiA+ICsgICAgICAgfQo+ID4gKwo+ID4gICAgICAgICBjaGVja19tZW1vcnlfcmVnaW9u KCh1bnNpZ25lZCBsb25nKXNyYywgbGVuLCBmYWxzZSwgX1JFVF9JUF8pOwo+ID4gICAgICAgICBj aGVja19tZW1vcnlfcmVnaW9uKCh1bnNpZ25lZCBsb25nKWRlc3QsIGxlbiwgdHJ1ZSwgX1JFVF9J UF8pOwo+ID4KPiA+Cj4gPiBjaGVja19tZW1vcnlfcmVnaW9uKCkgc3RpbGwgaGFzIHRvIGNoZWNr IHdoZXRoZXIgdGhlIHNpemUgaXMgbmVnYXRpdmUuCj4gPiBidXQgbWVtbW92ZS9tZW1zZXQvbWVt Y3B5IGdlbmVyYXRlIGludmFsaWQgc2l6ZSBLQVNBTiByZXBvcnQgd2lsbCBub3QgYmUKPiA+IHRo ZXJlLgo+IAo+IAo+IElmIGNoZWNrX21lbW9yeV9yZWdpb24oKSB3aWxsIGRvIHRoZSBjaGVjaywg d2h5IGRvIHdlIG5lZWQgdG8KPiBkdXBsaWNhdGUgaXQgaW5zaWRlIG9mIG1lbW1vdmUgYW5kIGFs bCBvdGhlciByYW5nZSBmdW5jdGlvbnM/Cj4gClllcywgSSBrbm93IGl0IGhhcyBkdXBsaWNhdGlv biwgYnV0IGlmIHdlIGRvbid0IGhhdmUgdG8gZGV0ZXJtaW5lIHNpemU8MAppbiBtZW1tb3ZlLCB0 aGVuIGFsbCBjaGVja19tZW1vcnlfcmVnaW9uIHJldHVybiBmYWxzZSB3aWxsIGRvIG5vdGhpbmcs Cml0IGluY2x1ZGVzIG90aGVyIG1lbW9yeSBjb3JydXB0aW9uIGJlaGF2aW9ycywgdGhpcyBpcyBt eSBvcmlnaW5hbApjb25jZXJuLiAKCj4gSSB3b3VsZCBkbzoKPiAKPiB2b2lkICptZW1tb3ZlKHZv aWQgKmRlc3QsIGNvbnN0IHZvaWQgKnNyYywgc2l6ZV90IGxlbikKPiB7Cj4gICAgICAgICBpZiAo Y2hlY2tfbWVtb3J5X3JlZ2lvbigodW5zaWduZWQgbG9uZylzcmMsIGxlbiwgZmFsc2UsIF9SRVRf SVBfKSkKPiAgICAgICAgICAgICAgICAgcmV0dXJuOwppZiBjaGVja19tZW1vcnlfcmVnaW9uIHJl dHVybiBUUlVFIGlzIHRvIGRvIG5vdGhpbmcsIGJ1dCBpdCBpcyBubyBtZW1vcnkKY29ycnVwdGlv bj8gU2hvdWxkIGl0IHJldHVybiBlYXJseSB3aGVuIGNoZWNrX21lbW9yeV9yZWdpb24gcmV0dXJu IGEKRkFMU0U/Cgo+IAo+IFRoaXMgYXZvaWRzIGR1cGxpY2F0aW5nIHRoZSBjaGVjaywgYWRkcyBt aW5pbWFsIGFtb3VudCBvZiBjb2RlIHRvCj4gcmFuZ2UgZnVuY3Rpb25zIGFuZCBhdm9pZHMgYWRk aW5nIGthc2FuX3JlcG9ydF9pbnZhbGlkX3NpemUuClRoYW5rcyBmb3IgeW91ciBzdWdnZXN0aW9u LgpXZSBvcmlnaW5hbGx5IHdhbnQgdG8gc2hvdyBjb21wbGV0ZSBpbmZvcm1hdGlvbihkZXN0aW5h dGlvbiBhZGRyZXNzLApzb3VyY2UgYWRkcmVzcywgYW5kIGl0cyBsZW5ndGgpLCBidXQgYWRkIG1p bmltYWwgYW1vdW50IG9mIGNvZGUgaW50bwprYXNhbl9yZXBvcnQoKSwgaXQgc2hvdWxkIGJlIGdv b2QuCgoKCl9fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fCmxp bnV4LWFybS1rZXJuZWwgbWFpbGluZyBsaXN0CmxpbnV4LWFybS1rZXJuZWxAbGlzdHMuaW5mcmFk ZWFkLm9yZwpodHRwOi8vbGlzdHMuaW5mcmFkZWFkLm9yZy9tYWlsbWFuL2xpc3RpbmZvL2xpbnV4 LWFybS1rZXJuZWwK From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, UNPARSEABLE_RELAY,USER_AGENT_SANE_2 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C2596C47404 for ; Thu, 3 Oct 2019 02:18:06 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 836DA222C2 for ; Thu, 3 Oct 2019 02:18:06 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 836DA222C2 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=mediatek.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 023446B0005; Wed, 2 Oct 2019 22:18:06 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id F3CC56B0006; Wed, 2 Oct 2019 22:18:05 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E52FD6B0007; Wed, 2 Oct 2019 22:18:05 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0124.hostedemail.com [216.40.44.124]) by kanga.kvack.org (Postfix) with ESMTP id BDD1A6B0005 for ; Wed, 2 Oct 2019 22:18:05 -0400 (EDT) Received: from smtpin18.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with SMTP id 6CDF2824CA3D for ; Thu, 3 Oct 2019 02:18:05 +0000 (UTC) X-FDA: 76000863330.18.walk02_c2f593091c29 X-HE-Tag: walk02_c2f593091c29 X-Filterd-Recvd-Size: 12153 Received: from mailgw02.mediatek.com (unknown [210.61.82.184]) by imf23.hostedemail.com (Postfix) with ESMTP for ; Thu, 3 Oct 2019 02:18:03 +0000 (UTC) X-UUID: 6a934931ebee47a7b59356e638e1e5f6-20191003 X-UUID: 6a934931ebee47a7b59356e638e1e5f6-20191003 Received: from mtkcas08.mediatek.inc [(172.21.101.126)] by mailgw02.mediatek.com (envelope-from ) (Cellopoint E-mail Firewall v4.1.10 Build 0809 with TLS) with ESMTP id 356317875; Thu, 03 Oct 2019 10:18:00 +0800 Received: from mtkcas09.mediatek.inc (172.21.101.178) by mtkmbs07n1.mediatek.inc (172.21.101.16) with Microsoft SMTP Server (TLS) id 15.0.1395.4; Thu, 3 Oct 2019 10:17:59 +0800 Received: from [172.21.84.99] (172.21.84.99) by mtkcas09.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.0.1395.4 via Frontend Transport; Thu, 3 Oct 2019 10:17:58 +0800 Message-ID: <1570069078.19702.57.camel@mtksdccf07> Subject: Re: [PATCH] kasan: fix the missing underflow in memmove and memcpy with CONFIG_KASAN_GENERIC=y From: Walter Wu To: Dmitry Vyukov CC: Andrey Ryabinin , Alexander Potapenko , Matthias Brugger , LKML , kasan-dev , Linux-MM , Linux ARM , , wsd_upstream Date: Thu, 3 Oct 2019 10:17:58 +0800 In-Reply-To: References: <20190927034338.15813-1-walter-zh.wu@mediatek.com> <1569594142.9045.24.camel@mtksdccf07> <1569818173.17361.19.camel@mtksdccf07> <1570018513.19702.36.camel@mtksdccf07> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.2.3-0ubuntu6 MIME-Version: 1.0 X-MTK: N Content-Transfer-Encoding: quoted-printable X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Wed, 2019-10-02 at 15:57 +0200, Dmitry Vyukov wrote: > On Wed, Oct 2, 2019 at 2:15 PM Walter Wu wr= ote: > > > > On Mon, 2019-09-30 at 12:36 +0800, Walter Wu wrote: > > > On Fri, 2019-09-27 at 21:41 +0200, Dmitry Vyukov wrote: > > > > On Fri, Sep 27, 2019 at 4:22 PM Walter Wu wrote: > > > > > > > > > > On Fri, 2019-09-27 at 15:07 +0200, Dmitry Vyukov wrote: > > > > > > On Fri, Sep 27, 2019 at 5:43 AM Walter Wu wrote: > > > > > > > > > > > > > > memmove() and memcpy() have missing underflow issues. > > > > > > > When -7 <=3D size < 0, then KASAN will miss to catch the un= derflow issue. > > > > > > > It looks like shadow start address and shadow end address i= s the same, > > > > > > > so it does not actually check anything. > > > > > > > > > > > > > > The following test is indeed not caught by KASAN: > > > > > > > > > > > > > > char *p =3D kmalloc(64, GFP_KERNEL); > > > > > > > memset((char *)p, 0, 64); > > > > > > > memmove((char *)p, (char *)p + 4, -2); > > > > > > > kfree((char*)p); > > > > > > > > > > > > > > It should be checked here: > > > > > > > > > > > > > > void *memmove(void *dest, const void *src, size_t len) > > > > > > > { > > > > > > > check_memory_region((unsigned long)src, len, false,= _RET_IP_); > > > > > > > check_memory_region((unsigned long)dest, len, true,= _RET_IP_); > > > > > > > > > > > > > > return __memmove(dest, src, len); > > > > > > > } > > > > > > > > > > > > > > We fix the shadow end address which is calculated, then gen= eric KASAN > > > > > > > get the right shadow end address and detect this underflow = issue. > > > > > > > > > > > > > > [1] https://bugzilla.kernel.org/show_bug.cgi?id=3D199341 > > > > > > > > > > > > > > Signed-off-by: Walter Wu > > > > > > > Reported-by: Dmitry Vyukov > > > > > > > --- > > > > > > > lib/test_kasan.c | 36 ++++++++++++++++++++++++++++++++++= ++ > > > > > > > mm/kasan/generic.c | 8 ++++++-- > > > > > > > 2 files changed, 42 insertions(+), 2 deletions(-) > > > > > > > > > > > > > > diff --git a/lib/test_kasan.c b/lib/test_kasan.c > > > > > > > index b63b367a94e8..8bd014852556 100644 > > > > > > > --- a/lib/test_kasan.c > > > > > > > +++ b/lib/test_kasan.c > > > > > > > @@ -280,6 +280,40 @@ static noinline void __init kmalloc_oo= b_in_memset(void) > > > > > > > kfree(ptr); > > > > > > > } > > > > > > > > > > > > > > +static noinline void __init kmalloc_oob_in_memmove_underfl= ow(void) > > > > > > > +{ > > > > > > > + char *ptr; > > > > > > > + size_t size =3D 64; > > > > > > > + > > > > > > > + pr_info("underflow out-of-bounds in memmove\n"); > > > > > > > + ptr =3D kmalloc(size, GFP_KERNEL); > > > > > > > + if (!ptr) { > > > > > > > + pr_err("Allocation failed\n"); > > > > > > > + return; > > > > > > > + } > > > > > > > + > > > > > > > + memset((char *)ptr, 0, 64); > > > > > > > + memmove((char *)ptr, (char *)ptr + 4, -2); > > > > > > > + kfree(ptr); > > > > > > > +} > > > > > > > + > > > > > > > +static noinline void __init kmalloc_oob_in_memmove_overflo= w(void) > > > > > > > +{ > > > > > > > + char *ptr; > > > > > > > + size_t size =3D 64; > > > > > > > + > > > > > > > + pr_info("overflow out-of-bounds in memmove\n"); > > > > > > > + ptr =3D kmalloc(size, GFP_KERNEL); > > > > > > > + if (!ptr) { > > > > > > > + pr_err("Allocation failed\n"); > > > > > > > + return; > > > > > > > + } > > > > > > > + > > > > > > > + memset((char *)ptr, 0, 64); > > > > > > > + memmove((char *)ptr + size, (char *)ptr, 2); > > > > > > > + kfree(ptr); > > > > > > > +} > > > > > > > + > > > > > > > static noinline void __init kmalloc_uaf(void) > > > > > > > { > > > > > > > char *ptr; > > > > > > > @@ -734,6 +768,8 @@ static int __init kmalloc_tests_init(vo= id) > > > > > > > kmalloc_oob_memset_4(); > > > > > > > kmalloc_oob_memset_8(); > > > > > > > kmalloc_oob_memset_16(); > > > > > > > + kmalloc_oob_in_memmove_underflow(); > > > > > > > + kmalloc_oob_in_memmove_overflow(); > > > > > > > kmalloc_uaf(); > > > > > > > kmalloc_uaf_memset(); > > > > > > > kmalloc_uaf2(); > > > > > > > diff --git a/mm/kasan/generic.c b/mm/kasan/generic.c > > > > > > > index 616f9dd82d12..34ca23d59e67 100644 > > > > > > > --- a/mm/kasan/generic.c > > > > > > > +++ b/mm/kasan/generic.c > > > > > > > @@ -131,9 +131,13 @@ static __always_inline bool memory_is_= poisoned_n(unsigned long addr, > > > > > > > size_t size= ) > > > > > > > { > > > > > > > unsigned long ret; > > > > > > > + void *shadow_start =3D kasan_mem_to_shadow((void *)= addr); > > > > > > > + void *shadow_end =3D kasan_mem_to_shadow((void *)ad= dr + size - 1) + 1; > > > > > > > > > > > > > > - ret =3D memory_is_nonzero(kasan_mem_to_shadow((void= *)addr), > > > > > > > - kasan_mem_to_shadow((void *)addr + = size - 1) + 1); > > > > > > > + if ((long)size < 0) > > > > > > > + shadow_end =3D kasan_mem_to_shadow((void *)= addr + size); > > > > > > > > > > > > Hi Walter, > > > > > > > > > > > > Thanks for working on this. > > > > > > > > > > > > If size<0, does it make sense to continue at all? We will sti= ll check > > > > > > 1PB of shadow memory? What happens when we pass such huge ran= ge to > > > > > > memory_is_nonzero? > > > > > > Perhaps it's better to produce an error and bail out immediat= ely if size<0? > > > > > > > > > > I agree with what you said. when size<0, it is indeed an unreas= onable > > > > > behavior, it should be blocked from continuing to do. > > > > > > > > > > > > > > > > Also, what's the failure mode of the tests? Didn't they badly= corrupt > > > > > > memory? We tried to keep tests such that they produce the KAS= AN > > > > > > reports, but don't badly corrupt memory b/c/ we need to run a= ll of > > > > > > them. > > > > > > > > > > Maybe we should first produce KASAN reports and then go to exec= ute > > > > > memmove() or do nothing? It looks like it=E2=80=99s doing the f= ollowing.or? > > > > > > > > > > void *memmove(void *dest, const void *src, size_t len) > > > > > { > > > > > + if (long(len) <=3D 0) > > > > > > > > /\/\/\/\/\/\ > > > > > > > > This check needs to be inside of check_memory_region, otherwise w= e > > > > will have similar problems in all other places that use > > > > check_memory_region. > > > Thanks for your reminder. > > > > > > bool check_memory_region(unsigned long addr, size_t size, bool wri= te, > > > unsigned long ret_ip) > > > { > > > + if (long(size) < 0) { > > > + kasan_report_invalid_size(src, dest, len, _RET_IP_)= ; > > > + return false; > > > + } > > > + > > > return check_memory_region_inline(addr, size, write, ret_ip= ); > > > } > > > > > > > But check_memory_region already returns a bool, so we could check= that > > > > bool and return early. > > > > > > When size<0, we should only show one KASAN report, and should we on= ly > > > limit to return when size<0 is true? If yse, then __memmove() will = do > > > nothing. > > > > > > > > > void *memmove(void *dest, const void *src, size_t len) > > > { > > > - check_memory_region((unsigned long)src, len, false, _RET_IP= _); > > > + if(!check_memory_region((unsigned long)src, len, false, > > > _RET_IP_) > > > + && long(size) < 0) > > > + return; > > > + > > > check_memory_region((unsigned long)dest, len, true, _RET_IP= _); > > > > > > return __memmove(dest, src, len); > > > > > > > > > Hi Dmitry, > > > > What do you think the following code is better than the above one. > > In memmmove/memset/memcpy, they need to determine whether size < 0 is > > true. we directly determine whether size is negative in memmove and > > return early. it avoid to generate repeated KASAN report. Is it bette= r? > > > > void *memmove(void *dest, const void *src, size_t len) > > { > > + if (long(size) < 0) { > > + kasan_report_invalid_size(src, dest, len, _RET_IP_); > > + return; > > + } > > + > > check_memory_region((unsigned long)src, len, false, _RET_IP_)= ; > > check_memory_region((unsigned long)dest, len, true, _RET_IP_)= ; > > > > > > check_memory_region() still has to check whether the size is negative= . > > but memmove/memset/memcpy generate invalid size KASAN report will not= be > > there. >=20 >=20 > If check_memory_region() will do the check, why do we need to > duplicate it inside of memmove and all other range functions? >=20 Yes, I know it has duplication, but if we don't have to determine size<0 in memmove, then all check_memory_region return false will do nothing, it includes other memory corruption behaviors, this is my original concern.=20 > I would do: >=20 > void *memmove(void *dest, const void *src, size_t len) > { > if (check_memory_region((unsigned long)src, len, false, _RET_IP= _)) > return; if check_memory_region return TRUE is to do nothing, but it is no memory corruption? Should it return early when check_memory_region return a FALSE? >=20 > This avoids duplicating the check, adds minimal amount of code to > range functions and avoids adding kasan_report_invalid_size. Thanks for your suggestion. We originally want to show complete information(destination address, source address, and its length), but add minimal amount of code into kasan_report(), it should be good.