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 2/3] exec: Make unlocking exec_update_mutex explict
Date: Mon, 06 Apr 2020 20:31:52 -0500 [thread overview]
Message-ID: <87imic3wtz.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")
With install_exec_creds updated to follow immediately after
setup_new_exec, the failure of unshare_sighand is the only
code path where exec_update_mutex is held but not explicitly
unlocked.
Update that code path to explicitly unlock exec_update_mutex.
Remove the unlocking of exec_update_mutex from free_bprm.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
---
fs/exec.c | 6 +++---
include/linux/binfmts.h | 3 +--
2 files changed, 4 insertions(+), 5 deletions(-)
diff --git a/fs/exec.c b/fs/exec.c
index d55710a36056..28c87020da9b 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -1318,7 +1318,7 @@ int flush_old_exec(struct linux_binprm * bprm)
*/
retval = unshare_sighand(me);
if (retval)
- goto out;
+ goto out_unlock;
set_fs(USER_DS);
me->flags &= ~(PF_RANDOMIZE | PF_FORKNOEXEC | PF_KTHREAD |
@@ -1335,6 +1335,8 @@ int flush_old_exec(struct linux_binprm * bprm)
do_close_on_exec(me->files);
return 0;
+out_unlock:
+ mutex_unlock(&me->signal->exec_update_mutex);
out:
return retval;
}
@@ -1451,8 +1453,6 @@ static void free_bprm(struct linux_binprm *bprm)
{
free_arg_pages(bprm);
if (bprm->cred) {
- if (bprm->called_exec_mmap)
- mutex_unlock(¤t->signal->exec_update_mutex);
mutex_unlock(¤t->signal->cred_guard_mutex);
abort_creds(bprm->cred);
}
diff --git a/include/linux/binfmts.h b/include/linux/binfmts.h
index a345d9fed3d8..6f564b9ad882 100644
--- a/include/linux/binfmts.h
+++ b/include/linux/binfmts.h
@@ -47,8 +47,7 @@ struct linux_binprm {
secureexec:1,
/*
* Set by flush_old_exec, when exec_mmap has been called.
- * This is past the point of no return, when the
- * exec_update_mutex has been taken.
+ * This is past the point of no return.
*/
called_exec_mmap:1;
#ifdef __alpha__
--
2.25.0
next prev parent reply other threads:[~2020-04-07 1:34 UTC|newest]
Thread overview: 127+ 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 ` Eric W. Biederman [this message]
2020-04-07 16:02 ` [PATCH 2/3] exec: Make unlocking exec_update_mutex explict Kees Cook
2020-04-07 16:17 ` Christian Brauner
2020-04-07 16:21 ` Eric W. Biederman
2020-04-07 1:32 ` [PATCH 3/3] exec: Rename the flag called_exec_mmap point_of_no_return Eric W. Biederman
2020-04-07 16:03 ` 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
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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