From patchwork Tue May 5 19:41:01 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Eric W. Biederman" X-Patchwork-Id: 11529803 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id B1674913 for ; Tue, 5 May 2020 19:44:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A17FC20721 for ; Tue, 5 May 2020 19:44:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728990AbgEETo2 (ORCPT ); Tue, 5 May 2020 15:44:28 -0400 Received: from out01.mta.xmission.com ([166.70.13.231]:41280 "EHLO out01.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728076AbgEETo1 (ORCPT ); Tue, 5 May 2020 15:44:27 -0400 Received: from in01.mta.xmission.com ([166.70.13.51]) by out01.mta.xmission.com with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1jW3UQ-00015n-63; Tue, 05 May 2020 13:44:26 -0600 Received: from ip68-227-160-95.om.om.cox.net ([68.227.160.95] helo=x220.xmission.com) by in01.mta.xmission.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.87) (envelope-from ) id 1jW3UP-0003hC-BF; Tue, 05 May 2020 13:44:26 -0600 From: ebiederm@xmission.com (Eric W. Biederman) To: Cc: Linus Torvalds , Oleg Nesterov , Jann Horn , Kees Cook , Greg Ungerer , Rob Landley , Bernd Edlinger , , Al Viro , Alexey Dobriyan , Andrew Morton References: <87h7wujhmz.fsf@x220.int.ebiederm.org> Date: Tue, 05 May 2020 14:41:01 -0500 In-Reply-To: <87h7wujhmz.fsf@x220.int.ebiederm.org> (Eric W. Biederman's message of "Tue, 05 May 2020 14:39:32 -0500") Message-ID: <87bln2jhki.fsf@x220.int.ebiederm.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.1 (gnu/linux) MIME-Version: 1.0 X-XM-SPF: eid=1jW3UP-0003hC-BF;;;mid=<87bln2jhki.fsf@x220.int.ebiederm.org>;;;hst=in01.mta.xmission.com;;;ip=68.227.160.95;;;frm=ebiederm@xmission.com;;;spf=neutral X-XM-AID: U2FsdGVkX18XA83hsY+wo44ZcwojdLYbAVD7/SyvSVE= X-SA-Exim-Connect-IP: 68.227.160.95 X-SA-Exim-Mail-From: ebiederm@xmission.com X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on sa05.xmission.com X-Spam-Level: ** X-Spam-Status: No, score=2.0 required=8.0 tests=ALL_TRUSTED,BAYES_50, DCC_CHECK_NEGATIVE,T_TM2_M_HEADER_IN_MSG,T_TooManySym_01,XMNoVowels, XMSubLong autolearn=disabled version=3.4.2 X-Spam-Report: * -1.0 ALL_TRUSTED Passed through trusted hosts only via SMTP * 0.8 BAYES_50 BODY: Bayes spam probability is 40 to 60% * [score: 0.5000] * 1.5 XMNoVowels Alpha-numberic number with no vowels * 0.7 XMSubLong Long Subject * 0.0 T_TM2_M_HEADER_IN_MSG BODY: No description available. * -0.0 DCC_CHECK_NEGATIVE Not listed in DCC * [sa05 0; Body=1 Fuz1=1 Fuz2=1] * 0.0 T_TooManySym_01 4+ unique symbols in subject X-Spam-DCC: ; sa05 0; Body=1 Fuz1=1 Fuz2=1 X-Spam-Combo: **; X-Spam-Relay-Country: X-Spam-Timing: total 433 ms - load_scoreonly_sql: 0.05 (0.0%), signal_user_changed: 13 (3.0%), b_tie_ro: 11 (2.6%), parse: 1.64 (0.4%), extract_message_metadata: 23 (5.4%), get_uri_detail_list: 3.3 (0.8%), tests_pri_-1000: 29 (6.6%), tests_pri_-950: 1.48 (0.3%), tests_pri_-900: 1.20 (0.3%), tests_pri_-90: 77 (17.9%), check_bayes: 76 (17.5%), b_tokenize: 11 (2.5%), b_tok_get_all: 8 (1.9%), b_comp_prob: 2.7 (0.6%), b_tok_touch_all: 50 (11.6%), b_finish: 0.85 (0.2%), tests_pri_0: 272 (62.7%), check_dkim_signature: 0.56 (0.1%), check_dkim_adsp: 2.4 (0.6%), poll_dns_idle: 0.66 (0.2%), tests_pri_10: 2.1 (0.5%), tests_pri_500: 8 (1.9%), rewrite_mail: 0.00 (0.0%) Subject: [PATCH 1/7] binfmt: Move install_exec_creds after setup_new_exec to match binfmt_elf X-Spam-Flag: No X-SA-Exim-Version: 4.2.1 (built Thu, 05 May 2016 13:38:54 -0600) X-SA-Exim-Scanned: Yes (on in01.mta.xmission.com) Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org In 2016 Linus moved install_exec_creds immediately after setup_new_exec, in binfmt_elf as a cleanup and as part of closing a potential information leak. Perform the same cleanup for the other binary formats. Different binary formats doing the same things the same way makes exec easier to reason about and easier to maintain. The binfmt_flagt bits were tested by Greg Ungerer Ref: 9f834ec18def ("binfmt_elf: switch to new creds when switching to new mm") Signed-off-by: "Eric W. Biederman" Reviewed-by: Kees Cook --- arch/x86/ia32/ia32_aout.c | 3 +-- fs/binfmt_aout.c | 2 +- fs/binfmt_elf_fdpic.c | 2 +- fs/binfmt_flat.c | 3 +-- 4 files changed, 4 insertions(+), 6 deletions(-) diff --git a/arch/x86/ia32/ia32_aout.c b/arch/x86/ia32/ia32_aout.c index 9bb71abd66bd..37b36a8ce5fa 100644 --- a/arch/x86/ia32/ia32_aout.c +++ b/arch/x86/ia32/ia32_aout.c @@ -140,6 +140,7 @@ static int load_aout_binary(struct linux_binprm *bprm) set_personality_ia32(false); setup_new_exec(bprm); + install_exec_creds(bprm); regs->cs = __USER32_CS; regs->r8 = regs->r9 = regs->r10 = regs->r11 = regs->r12 = @@ -156,8 +157,6 @@ static int load_aout_binary(struct linux_binprm *bprm) if (retval < 0) return retval; - install_exec_creds(bprm); - if (N_MAGIC(ex) == OMAGIC) { unsigned long text_addr, map_size; diff --git a/fs/binfmt_aout.c b/fs/binfmt_aout.c index 8e8346a81723..ace587b66904 100644 --- a/fs/binfmt_aout.c +++ b/fs/binfmt_aout.c @@ -162,6 +162,7 @@ static int load_aout_binary(struct linux_binprm * bprm) set_personality(PER_LINUX); #endif setup_new_exec(bprm); + install_exec_creds(bprm); current->mm->end_code = ex.a_text + (current->mm->start_code = N_TXTADDR(ex)); @@ -174,7 +175,6 @@ static int load_aout_binary(struct linux_binprm * bprm) if (retval < 0) return retval; - install_exec_creds(bprm); if (N_MAGIC(ex) == OMAGIC) { unsigned long text_addr, map_size; diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c index 240f66663543..6c94c6d53d97 100644 --- a/fs/binfmt_elf_fdpic.c +++ b/fs/binfmt_elf_fdpic.c @@ -353,6 +353,7 @@ static int load_elf_fdpic_binary(struct linux_binprm *bprm) current->personality |= READ_IMPLIES_EXEC; setup_new_exec(bprm); + install_exec_creds(bprm); set_binfmt(&elf_fdpic_format); @@ -434,7 +435,6 @@ static int load_elf_fdpic_binary(struct linux_binprm *bprm) current->mm->start_stack = current->mm->start_brk + stack_size; #endif - install_exec_creds(bprm); if (create_elf_fdpic_tables(bprm, current->mm, &exec_params, &interp_params) < 0) goto error; diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c index 831a2b25ba79..1a1d1fcb893f 100644 --- a/fs/binfmt_flat.c +++ b/fs/binfmt_flat.c @@ -541,6 +541,7 @@ static int load_flat_file(struct linux_binprm *bprm, /* OK, This is the point of no return */ set_personality(PER_LINUX_32BIT); setup_new_exec(bprm); + install_exec_creds(bprm); } /* @@ -963,8 +964,6 @@ static int load_flat_binary(struct linux_binprm *bprm) } } - install_exec_creds(bprm); - set_binfmt(&flat_format); #ifdef CONFIG_MMU