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From: ebiederm@xmission.com (Eric W. Biederman)
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Bernd Edlinger <bernd.edlinger@hotmail.de>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Alexey Gladkov <gladkov.alexey@gmail.com>,
	Oleg Nesterov <oleg@redhat.com>,
	Kees Cook <keescook@chromium.org>, Jann Horn <jannh@google.com>,
	Christian Brauner <christian.brauner@ubuntu.com>
Subject: [PATCH 3/3] exec: Rename the flag called_exec_mmap point_of_no_return
Date: Mon, 06 Apr 2020 20:32:23 -0500	[thread overview]
Message-ID: <87d08k3wt4.fsf_-_@x220.int.ebiederm.org> (raw)
In-Reply-To: <87wo6s3wxd.fsf_-_@x220.int.ebiederm.org> (Eric W. Biederman's message of "Mon, 06 Apr 2020 20:29:50 -0500")


Update the comments and make the code easier to understand by
renaming this flag.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
---
 fs/exec.c               | 12 ++++++------
 include/linux/binfmts.h |  6 +++---
 2 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/fs/exec.c b/fs/exec.c
index 28c87020da9b..a61987d6dc33 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -1300,12 +1300,12 @@ int flush_old_exec(struct linux_binprm * bprm)
 		goto out;
 
 	/*
-	 * After setting bprm->called_exec_mmap (to mark that current is
-	 * using the prepared mm now), we have nothing left of the original
-	 * process. If anything from here on returns an error, the check
-	 * in search_binary_handler() will SEGV current.
+	 * With the new mm installed it is completely impossible to
+	 * fail and return to the original process.  If anything from
+	 * here on returns an error, the check in
+	 * search_binary_handler() will SEGV current.
 	 */
-	bprm->called_exec_mmap = 1;
+	bprm->point_of_no_return = true;
 	bprm->mm = NULL;
 
 #ifdef CONFIG_POSIX_TIMERS
@@ -1694,7 +1694,7 @@ int search_binary_handler(struct linux_binprm *bprm)
 
 		read_lock(&binfmt_lock);
 		put_binfmt(fmt);
-		if (retval < 0 && bprm->called_exec_mmap) {
+		if (retval < 0 && bprm->point_of_no_return) {
 			/* we got to flush_old_exec() and failed after it */
 			read_unlock(&binfmt_lock);
 			force_sigsegv(SIGSEGV);
diff --git a/include/linux/binfmts.h b/include/linux/binfmts.h
index 6f564b9ad882..8f479dad7931 100644
--- a/include/linux/binfmts.h
+++ b/include/linux/binfmts.h
@@ -46,10 +46,10 @@ struct linux_binprm {
 		 */
 		secureexec:1,
 		/*
-		 * Set by flush_old_exec, when exec_mmap has been called.
-		 * This is past the point of no return.
+		 * Set when errors can no longer be returned to the
+		 * original userspace.
 		 */
-		called_exec_mmap:1;
+		point_of_no_return:1;
 #ifdef __alpha__
 	unsigned int taso:1;
 #endif
-- 
2.25.0


  parent reply	other threads:[~2020-04-07  1:35 UTC|newest]

Thread overview: 128+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <87blobnq02.fsf@x220.int.ebiederm.org>
2020-04-02 19:04 ` [GIT PULL] Please pull proc and exec work for 5.7-rc1 Linus Torvalds
2020-04-02 19:31   ` Bernd Edlinger
2020-04-02 19:52     ` Linus Torvalds
2020-04-02 20:59       ` Bernd Edlinger
2020-04-02 21:46         ` Linus Torvalds
2020-04-02 23:01           ` Eric W. Biederman
2020-04-02 23:42             ` Bernd Edlinger
2020-04-02 23:45               ` Eric W. Biederman
2020-04-02 23:49                 ` Bernd Edlinger
2020-04-02 23:45               ` Linus Torvalds
2020-04-02 23:44             ` Linus Torvalds
2020-04-03  0:05               ` Eric W. Biederman
2020-04-07  1:29               ` [RFC][PATCH 0/3] exec_update_mutex related cleanups Eric W. Biederman
2020-04-07  1:31                 ` [PATCH 1/3] binfmt: Move install_exec_creds after setup_new_exec to match binfmt_elf Eric W. Biederman
2020-04-07 15:58                   ` Kees Cook
2020-04-07 16:11                   ` Christian Brauner
2020-04-08 17:25                   ` Linus Torvalds
2020-04-08 19:51                     ` Eric W. Biederman
2020-04-07  1:31                 ` [PATCH 2/3] exec: Make unlocking exec_update_mutex explict Eric W. Biederman
2020-04-07 16:02                   ` Kees Cook
2020-04-07 16:17                   ` Christian Brauner
2020-04-07 16:21                     ` Eric W. Biederman
2020-04-07  1:32                 ` Eric W. Biederman [this message]
2020-04-07 16:03                   ` [PATCH 3/3] exec: Rename the flag called_exec_mmap point_of_no_return Kees Cook
2020-04-07 16:21                   ` Christian Brauner
2020-04-07 16:22                 ` [RFC][PATCH 0/3] exec_update_mutex related cleanups Christian Brauner
2020-04-08 17:26                 ` Linus Torvalds
2020-04-03  5:09             ` [GIT PULL] Please pull proc and exec work for 5.7-rc1 Bernd Edlinger
2020-04-03 19:26             ` Linus Torvalds
2020-04-03 20:41               ` Waiman Long
2020-04-03 20:59                 ` Linus Torvalds
2020-04-03 23:16                   ` Waiman Long
2020-04-03 23:23                     ` Waiman Long
2020-04-04  1:30                       ` Linus Torvalds
2020-04-04  2:02                         ` Waiman Long
2020-04-04  2:28                           ` Linus Torvalds
2020-04-04  6:34                             ` Bernd Edlinger
2020-04-05  6:34                               ` Bernd Edlinger
2020-04-05 19:35                                 ` Linus Torvalds
2020-04-05  2:42                             ` Waiman Long
2020-04-05  3:35                               ` Bernd Edlinger
2020-04-05  3:45                                 ` Waiman Long
2020-04-06 13:13                             ` Will Deacon
2020-04-04  4:23                     ` Bernd Edlinger
2020-04-06 22:17               ` Eric W. Biederman
2020-04-07 19:50                 ` Linus Torvalds
2020-04-07 20:29                   ` Bernd Edlinger
2020-04-07 20:47                     ` Linus Torvalds
2020-04-08 15:14                   ` Eric W. Biederman
2020-04-08 15:21                     ` Bernd Edlinger
2020-04-08 16:34                     ` Linus Torvalds
2020-04-09 14:58                       ` Eric W. Biederman
2020-04-09 15:15                         ` Bernd Edlinger
2020-04-09 16:15                         ` Linus Torvalds
2020-04-09 16:24                           ` Linus Torvalds
2020-04-09 17:03                             ` Eric W. Biederman
2020-04-09 17:17                               ` Bernd Edlinger
2020-04-09 17:37                                 ` Linus Torvalds
2020-04-09 17:46                                   ` Bernd Edlinger
2020-04-09 18:36                                     ` Linus Torvalds
2020-04-09 19:42                                       ` Linus Torvalds
2020-04-09 19:57                                         ` Bernd Edlinger
2020-04-09 20:04                                           ` Linus Torvalds
2020-04-09 20:36                                             ` Bernd Edlinger
2020-04-09 21:00                                             ` Eric W. Biederman
2020-04-09 21:17                                               ` Linus Torvalds
2020-04-09 23:52                                                 ` Bernd Edlinger
2020-04-10  0:30                                                 ` Linus Torvalds
2020-04-10  0:32                                                   ` Linus Torvalds
2020-04-11  4:07                                                     ` Bernd Edlinger
2020-04-11 18:20                                                   ` Oleg Nesterov
2020-04-11 18:29                                                     ` Linus Torvalds
2020-04-11 18:31                                                       ` Linus Torvalds
2020-04-11 19:15                                                       ` Bernd Edlinger
2020-04-11 20:07                                                         ` Linus Torvalds
2020-04-11 21:16                                                           ` Bernd Edlinger
     [not found]                                                             ` <CAHk-=wgWHkBzFazWJj57emHPd3Dg9SZHaZqoO7-AD+UbBTJgig@mail.gmail.com>
2020-04-11 21:57                                                               ` Linus Torvalds
2020-04-12  6:01                                                                 ` Bernd Edlinger
2020-04-12 19:50                                                       ` Oleg Nesterov
2020-04-12 20:14                                                         ` Linus Torvalds
2020-04-28  2:56                                                           ` Bernd Edlinger
2020-04-28 17:07                                                             ` Linus Torvalds
2020-04-28 19:08                                                               ` Oleg Nesterov
2020-04-28 20:35                                                                 ` Linus Torvalds
2020-04-28 21:06                                                                   ` Jann Horn
2020-04-28 21:36                                                                     ` Linus Torvalds
2020-04-28 21:53                                                                       ` Jann Horn
2020-04-28 22:14                                                                         ` Linus Torvalds
2020-04-28 23:36                                                                           ` Jann Horn
2020-04-29 17:58                                                                             ` Linus Torvalds
2020-04-29 18:33                                                                               ` Jann Horn
2020-04-29 18:57                                                                                 ` Linus Torvalds
2020-04-29 19:23                                                                               ` Bernd Edlinger
2020-04-29 19:26                                                                                 ` Jann Horn
2020-04-29 20:19                                                                                   ` Bernd Edlinger
2020-04-29 21:06                                                                                     ` Jann Horn
2020-04-29 22:38                                                                                 ` Linus Torvalds
2020-04-29 23:22                                                                                   ` Linus Torvalds
2020-04-29 23:59                                                                                     ` Jann Horn
2020-04-30  1:08                                                                                       ` Bernd Edlinger
2020-04-30  2:20                                                                                         ` Linus Torvalds
2020-04-30  3:00                                                                                           ` Jann Horn
2020-04-30  3:25                                                                                             ` Linus Torvalds
2020-04-30  3:41                                                                                               ` Jann Horn
2020-04-30  3:50                                                                                                 ` Linus Torvalds
2020-04-30 13:37                                                                                               ` Linus Torvalds
2020-04-30  2:16                                                                                       ` Linus Torvalds
2020-04-30 13:39                                                                                         ` Bernd Edlinger
2020-04-30 13:47                                                                                           ` Linus Torvalds
2020-04-30 14:29                                                                                             ` Bernd Edlinger
2020-04-30 16:40                                                                                               ` Linus Torvalds
2020-05-02  4:11                                                                                                 ` Bernd Edlinger
2025-08-24 22:28                                                                     ` Bernd Edlinger
2020-04-09 17:36                               ` Linus Torvalds
2020-04-09 20:34                                 ` Eric W. Biederman
2020-04-09 20:56                                   ` Linus Torvalds
2020-04-02 23:02           ` Bernd Edlinger
2020-04-02 23:22           ` Bernd Edlinger
2020-04-03  7:38           ` Bernd Edlinger
2020-04-03 16:00       ` Bernd Edlinger
2020-04-03 15:09   ` Bernd Edlinger
2020-04-03 16:23     ` Linus Torvalds
2020-04-03 16:36       ` Bernd Edlinger
2020-04-04  5:43       ` Bernd Edlinger
2020-04-04  5:48         ` Bernd Edlinger
2020-04-06  6:41           ` Bernd Edlinger
2020-04-10 13:03 ` [GIT PULL] proc fix " Eric W. Biederman
2020-04-10 20:40   ` pr-tracker-bot

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