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=-3.9 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no 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 16E31C2D0A8 for ; Wed, 23 Sep 2020 10:30:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 91D522388A for ; Wed, 23 Sep 2020 10:30:19 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=alien8.de header.i=@alien8.de header.b="a7FHINvw" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726636AbgIWKaS (ORCPT ); Wed, 23 Sep 2020 06:30:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53122 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726419AbgIWKaR (ORCPT ); Wed, 23 Sep 2020 06:30:17 -0400 Received: from mail.skyhub.de (mail.skyhub.de [IPv6:2a01:4f8:190:11c2::b:1457]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8961FC0613CE for ; Wed, 23 Sep 2020 03:30:17 -0700 (PDT) Received: from zn.tnic (p200300ec2f0d1300e5068c8a3292d31d.dip0.t-ipconnect.de [IPv6:2003:ec:2f0d:1300:e506:8c8a:3292:d31d]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.skyhub.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id B0C3F1EC0409; Wed, 23 Sep 2020 12:30:15 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1600857015; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:in-reply-to:in-reply-to: references:references; bh=QeE5wPLAtIBCyxy/tK03AVY/XVSUEjZ0YhJ2DYbcq1g=; b=a7FHINvw0Iz8zavQTKRuXc4UYccSt9jbCsZn9CKyy7QRl+vTAqy6IjBFzh0Ywi5uMq07up v0C7h9Pb4JyTKtCjHolVnf7n+HsM8NFBb2QpOqcKxqEOhFXDDseXA0+K7ww3/QLTTZuCwm qdqEm+vYEXxt/fjPBr1000jOpJcTOig= Date: Wed, 23 Sep 2020 12:30:08 +0200 From: Borislav Petkov To: Dmitry Vyukov Cc: syzbot , "H. Peter Anvin" , LKML , Andy Lutomirski , Ingo Molnar , syzkaller-bugs , Thomas Gleixner , the arch/x86 maintainers , clang-built-linux Subject: Re: invalid opcode in map_vdso Message-ID: <20200923103008.GE28545@zn.tnic> References: <00000000000096760d05aff79022@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Sep 23, 2020 at 11:19:40AM +0200, Dmitry Vyukov wrote: > +clang-built-linux > Looks like another one with kernel code overwrite in clang build. Uuh, that's a nice and refreshing one - the pattern is not zeroes this time Code: 16 48 89 ef 48 8b 34 24 31 c9 e8 88 7c a7 00 eb 7a 4c 8b 74 24 28 43 80 3c 3e 00 48 8b 5c 24 08 74 08 4c 89 ef e8 4d 77 70 70 <07> 20 05 00 00 49 03 6d 00 48 89 e8 48 c1 e8 03 42 80 3c 38 00 74 All code ======== 0: 16 (bad) 1: 48 89 ef mov %rbp,%rdi 4: 48 8b 34 24 mov (%rsp),%rsi 8: 31 c9 xor %ecx,%ecx a: e8 88 7c a7 00 callq 0xa77c97 f: eb 7a jmp 0x8b 11: 4c 8b 74 24 28 mov 0x28(%rsp),%r14 16: 43 80 3c 3e 00 cmpb $0x0,(%r14,%r15,1) 1b: 48 8b 5c 24 08 mov 0x8(%rsp),%rbx 20: 74 08 je 0x2a 22: 4c 89 ef mov %r13,%rdi 25: e8 4d 77 70 70 callq 0x70707777 2a:* 07 (bad) <-- trapping instruction 2b: 20 05 00 00 49 03 and %al,0x3490000(%rip) # 0x3490031 31: 6d insl (%dx),%es:(%rdi) 32: 00 48 89 add %cl,-0x77(%rax) 35: e8 48 c1 e8 03 callq 0x3e8c182 3a: 42 80 3c 38 00 cmpb $0x0,(%rax,%r15,1) 3f: 74 .byte 0x74 Code starting with the faulting instruction =========================================== 0: 07 (bad) 1: 20 05 00 00 49 03 and %al,0x3490000(%rip) # 0x3490007 7: 6d insl (%dx),%es:(%rdi) 8: 00 48 89 add %cl,-0x77(%rax) b: e8 48 c1 e8 03 callq 0x3e8c158 10: 42 80 3c 38 00 cmpb $0x0,(%rax,%r15,1) 15: 74 .byte 0x74 -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette