Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759454AbXHBTKm (ORCPT ); Thu, 2 Aug 2007 15:10:42 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753090AbXHBTKd (ORCPT ); Thu, 2 Aug 2007 15:10:33 -0400 Received: from deine-taler.de ([217.160.107.63]:55919 "EHLO deine-taler.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754087AbXHBTKc (ORCPT ); Thu, 2 Aug 2007 15:10:32 -0400 Date: Thu, 2 Aug 2007 21:10:31 +0200 From: Ulrich Kunitz To: Sergey Vlasov Cc: Chuck Ebbert , linux-kernel@vger.kernel.org, honza@jikos.cz, jkosina@suse.cz, "H. Peter Anvin" Subject: Re: Is PIE randomization breaking klibc binaries? Message-ID: <20070802191031.GA9750@deine-taler.de> References: <20070720211300.GA21644@deine-taler.de> <46A131BF.4080404@zytor.com> <46A6624E.60003@redhat.com> <46A667BD.5080106@redhat.com> <20070724220053.GA20531@deine-taler.de> <46A68003.6060901@redhat.com> <46A68118.9080902@zytor.com> <20070725063243.GA25148@deine-taler.de> <20070802230219.97b7f7b5.vsu@altlinux.ru> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20070802230219.97b7f7b5.vsu@altlinux.ru> User-Agent: Mutt/1.5.13 (2006-08-11) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4459 Lines: 101 Sergey Vlasov wrote: > On Wed, 25 Jul 2007 08:32:43 +0200 Ulrich Kunitz wrote: > > [...] > > Here is some output from objdump: > > > > $ objdump -x bin/sleep > > > > bin/sleep: file format elf64-x86-64 > > bin/sleep > > architecture: i386:x86-64, flags 0x00000102: > > EXEC_P, D_PAGED > > start address 0x000000000040014c > > > > Program Header: > > PHDR off 0x0000000000000040 vaddr 0x0000000000400040 paddr 0x0000000000400040 align 2**3 > > filesz 0x00000000000000e0 memsz 0x00000000000000e0 flags r-x > > INTERP off 0x0000000000000120 vaddr 0x0000000000400120 paddr 0x0000000000400120 align 2**0 > > filesz 0x000000000000002a memsz 0x000000000000002a flags r-- > > LOAD off 0x0000000000000000 vaddr 0x0000000000400000 paddr 0x0000000000400000 align 2**21 > > filesz 0x00000000000001c3 memsz 0x00000000000001c3 flags r-x > > STACK off 0x0000000000000000 vaddr 0x0000000000000000 paddr 0x0000000000000000 align 2**3 > > filesz 0x0000000000000000 memsz 0x0000000000000000 flags rwx > > > > Sections: > > Idx Name Size VMA LMA File off Algn > > 0 .interp 0000002a 0000000000400120 0000000000400120 00000120 2**0 > > CONTENTS, ALLOC, LOAD, READONLY, DATA > > 1 .text 00000059 000000000040014c 000000000040014c 0000014c 2**2 > > CONTENTS, ALLOC, LOAD, READONLY, CODE > > 2 .rodata 0000001e 00000000004001a5 00000000004001a5 000001a5 2**0 > > CONTENTS, ALLOC, LOAD, READONLY, DATA > > 3 .gnu_debuglink 0000000c 0000000000000000 0000000000000000 000001c3 2**0 > > CONTENTS, READONLY > > SYMBOL TABLE: > > no symbols > > > > > > $ objdump -x lib/klibc-7q-hWrI8UIRMp59zIo378Yl2X7A.so > >. What version of klibc is this? I think you found it: 1.4.30-3ubuntu2. > > > > > lib/klibc-7q-hWrI8UIRMp59zIo378Yl2X7A.so: file format elf64-x86-64 > > lib/klibc-7q-hWrI8UIRMp59zIo378Yl2X7A.so > > architecture: i386:x86-64, flags 0x00000102: > > EXEC_P, D_PAGED > > start address 0x0000000000200200 > > > > Program Header: > > LOAD off 0x0000000000000000 vaddr 0x0000000000200000 paddr 0x0000000000200000 align 2**21 > > filesz 0x000000000001197e memsz 0x000000000001197e flags r-x > > LOAD off 0x0000000000011980 vaddr 0x0000000000411980 paddr 0x0000000000411980 align 2**21 > > Note that the vaddr here can overlap the binary which is linked starting > at 0x400000. > > This is the bug which I have found and fixed some time ago: > > http://git.kernel.org/?p=libs/klibc/klibc.git;a=commit;h=10df6dfb13ffefe716f12136bbc667f18ff64744 > > The fix was included in klibc-1.4.35, but does not seem to be applied in > your case (the alignment is still 2**21 - it should be 2**20) - so > either you are using an old klibc, or the "-z max-page-size=0x100000" > option does not take effect for some reason. > > In my case the buggy klibc worked fine with a stock 2.6.18 kernel, but > broke when the execshield patch was applied - and the commit 60bfba7e > code comes from execshield, so it looks like the same problem. > > > filesz 0x0000000000000100 memsz 0x0000000000004288 flags rw- > > STACK off 0x0000000000000000 vaddr 0x0000000000000000 paddr 0x0000000000000000 align 2**3 > > filesz 0x0000000000000000 memsz 0x0000000000000000 flags rwx > > > > Sections: > > Idx Name Size VMA LMA File off Algn > > 0 .text 0000da94 0000000000200200 0000000000200200 00000200 2**2 > > CONTENTS, ALLOC, LOAD, READONLY, CODE > > 1 .rodata 00003cde 000000000020dca0 000000000020dca0 0000dca0 2**5 > > CONTENTS, ALLOC, LOAD, READONLY, DATA > > 2 .data 00000100 0000000000411980 0000000000411980 00011980 2**5 > > CONTENTS, ALLOC, LOAD, DATA > > 3 .bss 00004188 0000000000411a80 0000000000411a80 00011a80 2**5 > > ALLOC > > 4 .gnu_debuglink 0000002c 0000000000000000 0000000000000000 00011a80 2**0 > > CONTENTS, READONLY > > SYMBOL TABLE: > > no symbols > > -- Uli Kunitz - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/