diff --git a/fs/proc/base.c b/fs/proc/base.c
index 529d0c6ec6f9..b690074e65ff 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -1036,7 +1036,6 @@ static ssize_t oom_adj_read(struct file *file, char __user *buf, size_t count,
 
 static int __set_oom_adj(struct file *file, int oom_adj, bool legacy)
 {
-	static DEFINE_MUTEX(oom_adj_mutex);
 	struct mm_struct *mm = NULL;
 	struct task_struct *task;
 	int err = 0;
@@ -1076,7 +1075,7 @@ static int __set_oom_adj(struct file *file, int oom_adj, bool legacy)
 		struct task_struct *p = find_lock_task_mm(task);
 
 		if (p) {
-			if (atomic_read(&p->mm->mm_users) > 1) {
+			if (test_bit(MMF_MULTIPROCESS, &p->mm->flags)) {
 				mm = p->mm;
 				mmgrab(mm);
 			}
diff --git a/include/linux/oom.h b/include/linux/oom.h
index c696c265f019..b9df34326772 100644
--- a/include/linux/oom.h
+++ b/include/linux/oom.h
@@ -55,6 +55,7 @@ struct oom_control {
 };
 
 extern struct mutex oom_lock;
+extern struct mutex oom_adj_mutex;
 
 static inline void set_current_oom_origin(void)
 {
diff --git a/include/linux/sched/coredump.h b/include/linux/sched/coredump.h
index ecdc6542070f..dfd82eab2902 100644
--- a/include/linux/sched/coredump.h
+++ b/include/linux/sched/coredump.h
@@ -72,6 +72,7 @@ static inline int get_dumpable(struct mm_struct *mm)
 #define MMF_DISABLE_THP		24	/* disable THP for all VMAs */
 #define MMF_OOM_VICTIM		25	/* mm is the oom victim */
 #define MMF_OOM_REAP_QUEUED	26	/* mm was queued for oom_reaper */
+#define MMF_MULTIPROCESS	27	/* mm is shared between processes */
 #define MMF_DISABLE_THP_MASK	(1 << MMF_DISABLE_THP)
 
 #define MMF_INIT_MASK		(MMF_DUMPABLE_MASK | MMF_DUMP_FILTER_MASK |\
diff --git a/kernel/fork.c b/kernel/fork.c
index 594272569a80..e3d5963d8c6f 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1750,6 +1750,25 @@ static __always_inline void delayed_free_task(struct task_struct *tsk)
 		free_task(tsk);
 }
 
+static void copy_oom_score_adj(u64 clone_flags, struct task_struct *tsk)
+{
+	/* Skip if kernel thread */
+	if (!tsk->mm)
+		return;
+
+	/* Skip if spawning a thread or using vfork */
+	if ((clone_flags & (CLONE_VM | CLONE_THREAD | CLONE_VFORK)) != CLONE_VM)
+		return;
+
+	/* We need to synchronize with __set_oom_adj */
+	mutex_lock(&oom_adj_mutex);
+	set_bit(MMF_MULTIPROCESS, &tsk->mm->flags);
+	/* Update the values in case they were changed after copy_signal */
+	tsk->signal->oom_score_adj = current->signal->oom_score_adj;
+	tsk->signal->oom_score_adj_min = current->signal->oom_score_adj_min;
+	mutex_unlock(&oom_adj_mutex);
+}
+
 /*
  * This creates a new process as a copy of the old one,
  * but does not actually start it yet.
@@ -2222,6 +2241,8 @@ static __latent_entropy struct task_struct *copy_process(
 	trace_task_newtask(p, clone_flags);
 	uprobe_copy_process(p, clone_flags);
 
+	copy_oom_score_adj(clone_flags, p);
+
 	return p;
 
 bad_fork_cancel_cgroup:
diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index d58c481b3df8..212e71874301 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -63,6 +63,8 @@ int sysctl_oom_dump_tasks = 1;
  * and mark_oom_victim
  */
 DEFINE_MUTEX(oom_lock);
+/* Serializes oom_score_adj and oom_score_adj_min updates */
+DEFINE_MUTEX(oom_adj_mutex);
 
 static inline bool is_memcg_oom(struct oom_control *oc)
 {