lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Fri, 13 Nov 2015 21:09:50 -0500 From: Jessica Yu <jeyu@...hat.com> To: Miroslav Benes <mbenes@...e.cz> Cc: Josh Poimboeuf <jpoimboe@...hat.com>, Petr Mladek <pmladek@...e.com>, Rusty Russell <rusty@...tcorp.com.au>, Seth Jennings <sjenning@...hat.com>, Jiri Kosina <jikos@...nel.org>, Vojtech Pavlik <vojtech@...e.com>, linux-api@...r.kernel.org, live-patching@...r.kernel.org, x86@...nel.org, linux-kernel@...r.kernel.org Subject: Re: module: save load_info for livepatch modules +++ Miroslav Benes [13/11/15 13:56 +0100]: >On Fri, 13 Nov 2015, Miroslav Benes wrote: > >> I agree this seems like the best approach. So if we preserve >> mod_arch_syminfo (in case of s390) we should free it not in >> module_finalize, but somewhere in free_module... where >> module_arch_cleanup() is called... and also module_arch_freeing_init() is >> called there too. And what you find there for s390 is >> >> vfree(mod->arch.syminfo); >> mod->arch.syminfo = NULL; >> >> Well, it does nothing here, because mod->arch.syminfo is already NULL. It >> was freed in module_finalize. So we can even remove this code from >> module_finalize and all should be fine. At least for s390. > >Which is not true because module_arch_freeing_init is also called from >do_init_module, called from load_module. So we should move it to >module_arch_cleanup. > >That code is like a maze without Ariadne's thread. Heh, I agree with that sentiment. I am slightly confused about the s390 code, and whether the authors originally intended for that double vfree() to happen in both module_finalize() and module_arch_freeing_init() (called from do_init_module). Seems like a mistake. If module load succeeds, do_init_module calls module_arch_freeing_init(). And if load_module fails halfway through, both module_deallocate() and free_module() will also call module_arch_freeing_init(). I feel like that vfree should only happen once in module_arch_freeing_init() and not in module_finalize(). If we can remove the double vfree() code from module_finalize(), we can copy the mod_arch_specific safely before the call to do_init_module(). Jessica -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists