Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754262AbaKNAMs (ORCPT ); Thu, 13 Nov 2014 19:12:48 -0500 Received: from mx1.redhat.com ([209.132.183.28]:41140 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754232AbaKNAMr (ORCPT ); Thu, 13 Nov 2014 19:12:47 -0500 Date: Fri, 14 Nov 2014 01:11:59 +0100 From: Oleg Nesterov To: David Drysdale , Andrew Morton Cc: Meredydd Luff , Shuah Khan , "Eric W. Biederman" , Andy Lutomirski , Alexander Viro , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Kees Cook , Arnd Bergmann , Rich Felker , Christoph Hellwig , Michael Kerrisk , linux-kernel@vger.kernel.org Subject: Re: + syscallsx86-implement-execveat-system-call.patch added to -mm tree Message-ID: <20141114001159.GA31545@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > @@ -1479,7 +1489,26 @@ static int do_execve_common(struct filen > > bprm->file = file; > - bprm->filename = bprm->interp = filename->name; > + if (fd == AT_FDCWD || filename->name[0] == '/') { > + bprm->filename = filename->name; > + } else { > + if (filename->name[0] == '\0') > + pathbuf = kasprintf(GFP_TEMPORARY, "/dev/fd/%d", fd); > + else > + pathbuf = kasprintf(GFP_TEMPORARY, "/dev/fd/%d/%s", > + fd, filename->name); > + if (!pathbuf) { > + retval = -ENOMEM; > + goto out_unmark; > + } > + /* Record that a name derived from an O_CLOEXEC fd will be > + * inaccessible after exec. Relies on having exclusive access to > + * current->files (due to unshare_files above). */ > + if (close_on_exec(fd, current->files->fdt)) > + bprm->interp_flags |= BINPRM_FLAGS_PATH_INACCESSIBLE; > + bprm->filename = pathbuf; + } + bprm->interp = bprm->filename; Not sure I understand this patch, will try to read later... Just once question, don't we leak pathbuf if exec() succeeds? OTOH, if it fails, > out_free: > free_bprm(bprm); > + kfree(pathbuf); Is it correct if we fail after bprm_change_interp() was called? It seems that we can free interp == pathbuf twice? Oleg. -- 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/