+ exec-fix-dead-lock-in-de_thread-with-ptrace_attach-v9.patch added to -mm tree

[akpm@linux-foundation.org]

The patch titled
     Subject: exec-fix-dead-lock-in-de_thread-with-ptrace_attach-v9
has been added to the -mm tree.  Its filename is
     exec-fix-dead-lock-in-de_thread-with-ptrace_attach-v9.patch

This patch should soon appear at
    https://ozlabs.org/~akpm/mmots/broken-out/exec-fix-dead-lock-in-de_thread-with-ptrace_attach-v9.patch
and later at
    https://ozlabs.org/~akpm/mmotm/broken-out/exec-fix-dead-lock-in-de_thread-with-ptrace_attach-v9.patch

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------------------------------------------------------
From: Bernd Edlinger <bernd.edlinger@hotmail.de>
Subject: exec-fix-dead-lock-in-de_thread-with-ptrace_attach-v9

Link: https://lkml.kernel.org/r/AM8PR10MB470896FBC519ABCC20486958E4349@AM8PR10MB4708.EURPRD10.PROD.OUTLOOK.COM
Signed-off-by: Bernd Edlinger <bernd.edlinger@hotmail.de>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Will Drewry <wad@chromium.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Serge Hallyn <serge@hallyn.com>
Cc: James Morris <jamorris@linux.microsoft.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Charles Haithcock <chaithco@redhat.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Yafang Shao <laoar.shao@gmail.com>
Cc: Helge Deller <deller@gmx.de>
Cc: YiFei Zhu <yifeifz2@illinois.edu>
Cc: Adrian Reber <areber@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 fs/exec.c |   26 ++++++++++++++------------
 1 file changed, 14 insertions(+), 12 deletions(-)

--- a/fs/exec.c~exec-fix-dead-lock-in-de_thread-with-ptrace_attach-v9
+++ a/fs/exec.c
@@ -1056,29 +1056,31 @@ static int de_thread(struct task_struct
 		return -EAGAIN;
 	}
 
-	while_each_thread(tsk, t) {
-		if (unlikely(t->ptrace) && t != tsk->group_leader)
-			sig->unsafe_execve_in_progress = true;
-	}
-
 	sig->group_exit_task = tsk;
 	sig->notify_count = zap_other_threads(tsk);
 	if (!thread_group_leader(tsk))
 		sig->notify_count--;
-	spin_unlock_irq(lock);
 
-	if (unlikely(sig->unsafe_execve_in_progress))
+	while_each_thread(tsk, t) {
+		if (unlikely(t->ptrace) && t != tsk->group_leader)
+			sig->unsafe_execve_in_progress = true;
+	}
+
+	if (unlikely(sig->unsafe_execve_in_progress)) {
+		spin_unlock_irq(lock);
 		mutex_unlock(&sig->cred_guard_mutex);
+		spin_lock_irq(lock);
+	}
 
-	for (;;) {
-		set_current_state(TASK_KILLABLE);
-		if (!sig->notify_count)
-			break;
+	while (sig->notify_count) {
+		__set_current_state(TASK_KILLABLE);
+		spin_unlock_irq(lock);
 		schedule();
 		if (__fatal_signal_pending(tsk))
 			goto killed;
+		spin_lock_irq(lock);
 	}
-	__set_current_state(TASK_RUNNING);
+	spin_unlock_irq(lock);
 
 	if (unlikely(sig->unsafe_execve_in_progress)) {
 		if (mutex_lock_killable(&sig->cred_guard_mutex))
_

Patches currently in -mm which might be from bernd.edlinger@hotmail.de are

exec-fix-dead-lock-in-de_thread-with-ptrace_attach.patch
exec-fix-dead-lock-in-de_thread-with-ptrace_attach-v9.patch