diff options
| author | Bernd Edlinger <bernd.edlinger@hotmail.de> | 2020-03-21 02:46:16 +0000 |
|---|---|---|
| committer | Eric W. Biederman <ebiederm@xmission.com> | 2020-03-25 10:04:01 -0500 |
| commit | 501f9328bf5c6b5e4863da4b50e0e86792de3aa9 (patch) | |
| tree | 1daa6f09d76a01c93cb59372e85e017a833ca5c9 | |
| parent | 6914303824bb572278568330d72fc1f8f9814e67 (diff) | |
pidfd: Use new infrastructure to fix deadlocks in execve
This changes __pidfd_fget to use the new exec_update_mutex
instead of cred_guard_mutex.
This should be safe, as the credentials do not change
before exec_update_mutex is locked. Therefore whatever
file access is possible with holding the cred_guard_mutex
here is also possbile with the exec_update_mutex.
Signed-off-by: Bernd Edlinger <bernd.edlinger@hotmail.de>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
| -rw-r--r-- | kernel/pid.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/kernel/pid.c b/kernel/pid.c index 60820e72634c..efd34874b3d1 100644 --- a/kernel/pid.c +++ b/kernel/pid.c @@ -577,7 +577,7 @@ static struct file *__pidfd_fget(struct task_struct *task, int fd) struct file *file; int ret; - ret = mutex_lock_killable(&task->signal->cred_guard_mutex); + ret = mutex_lock_killable(&task->signal->exec_update_mutex); if (ret) return ERR_PTR(ret); @@ -586,7 +586,7 @@ static struct file *__pidfd_fget(struct task_struct *task, int fd) else file = ERR_PTR(-EPERM); - mutex_unlock(&task->signal->cred_guard_mutex); + mutex_unlock(&task->signal->exec_update_mutex); return file ?: ERR_PTR(-EBADF); } |