kernel/ptrace.c | 21 ++++++++++++++++++---
 1 file changed, 18 insertions(+), 3 deletions(-)

diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index 43d6179508d6..ebbc9876914b 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -31,6 +31,7 @@
 #include <linux/cn_proc.h>
 #include <linux/compat.h>
 #include <linux/sched/signal.h>
+#include <linux/delay.h>
 
 #include <asm/syscall.h>	/* for syscall_get_* */
 
@@ -390,10 +391,24 @@ static int ptrace_attach(struct task_struct *task, long request,
 	 * Protect exec's credential calculations against our interference;
 	 * SUID, SGID and LSM creds get determined differently
 	 * under ptrace.
+	 *
+	 * Don't wait forever on the credential lock if the target is
+	 * going through an execve.
+	 *
+	 * Whatever. We don't have "mutex_lock_interruptible_timeout()".
+	 * But this would be a disgusting hack even with it.
 	 */
-	retval = -ERESTARTNOINTR;
-	if (mutex_lock_interruptible(&task->signal->cred_guard_mutex))
-		goto out;
+	for (;;) {
+		if (mutex_trylock(&task->signal->cred_guard_mutex))
+			break;
+		retval = -ERESTARTNOINTR;
+		if (signal_pending(current))
+			goto out;
+		retval = -EAGAIN;
+		if (task->in_execve)
+			goto out;
+		msleep_interruptible(100);
+	}
 
 	task_lock(task);
 	retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH_REALCREDS);