proc: Use new infrastructure to fix deadlocks in execve
[ Upstream commit 2db9dbf71b
]
This changes lock_trace to use the new exec_update_mutex
instead of cred_guard_mutex.
This fixes possible deadlocks when the trace is accessing
/proc/$pid/stack for instance.
This should be safe, as the credentials are only used for reading,
and task->mm is updated on execve under the new exec_update_mutex.
Signed-off-by: Bernd Edlinger <bernd.edlinger@hotmail.de>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
5.4-rM2-2.2.x-imx-squashed
parent
0cd9783686
commit
4301db49e5
|
@ -403,11 +403,11 @@ print0:
|
|||
|
||||
static int lock_trace(struct task_struct *task)
|
||||
{
|
||||
int err = mutex_lock_killable(&task->signal->cred_guard_mutex);
|
||||
int err = mutex_lock_killable(&task->signal->exec_update_mutex);
|
||||
if (err)
|
||||
return err;
|
||||
if (!ptrace_may_access(task, PTRACE_MODE_ATTACH_FSCREDS)) {
|
||||
mutex_unlock(&task->signal->cred_guard_mutex);
|
||||
mutex_unlock(&task->signal->exec_update_mutex);
|
||||
return -EPERM;
|
||||
}
|
||||
return 0;
|
||||
|
@ -415,7 +415,7 @@ static int lock_trace(struct task_struct *task)
|
|||
|
||||
static void unlock_trace(struct task_struct *task)
|
||||
{
|
||||
mutex_unlock(&task->signal->cred_guard_mutex);
|
||||
mutex_unlock(&task->signal->exec_update_mutex);
|
||||
}
|
||||
|
||||
#ifdef CONFIG_STACKTRACE
|
||||
|
|
Loading…
Reference in New Issue