diff --git a/arch/Kconfig b/arch/Kconfig
index 7a8e3d45b2a1c477e3ca006866114702d22f5cf4..d2c7203dfaefb4eeb03fd758c470426a64faf88f 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -1119,6 +1119,9 @@ config ARCH_SPLIT_ARG64
 	   If a 32-bit architecture requires 64-bit arguments to be split into
 	   pairs of 32-bit arguments, select this option.
 
+config DYNAMIC_SIGFRAME
+	bool
+
 source "kernel/gcov/Kconfig"
 
 source "scripts/gcc-plugins/Kconfig"
diff --git a/include/linux/signal.h b/include/linux/signal.h
index b256f9c65661cca7a5314af58aadac76b2a10f07..3038a06104075b7bfc0360bd94753ad4f1929bb4 100644
--- a/include/linux/signal.h
+++ b/include/linux/signal.h
@@ -464,6 +464,12 @@ int __save_altstack(stack_t __user *, unsigned long);
 		sas_ss_reset(t); \
 } while (0);
 
+#ifdef CONFIG_DYNAMIC_SIGFRAME
+bool sigaltstack_size_valid(size_t ss_size);
+#else
+static inline bool sigaltstack_size_valid(size_t size) { return true; }
+#endif /* !CONFIG_DYNAMIC_SIGFRAME */
+
 #ifdef CONFIG_PROC_FS
 struct seq_file;
 extern void render_sigset_t(struct seq_file *, const char *, sigset_t *);
diff --git a/kernel/signal.c b/kernel/signal.c
index 54f86e0b97f383fdee683b033db0f37faa0c504b..ce95a76fe60ae983179451c7c47e3321284ce3b1 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -4010,11 +4010,29 @@ int do_sigaction(int sig, struct k_sigaction *act, struct k_sigaction *oact)
 	return 0;
 }
 
+#ifdef CONFIG_DYNAMIC_SIGFRAME
+static inline void sigaltstack_lock(void)
+	__acquires(&current->sighand->siglock)
+{
+	spin_lock_irq(&current->sighand->siglock);
+}
+
+static inline void sigaltstack_unlock(void)
+	__releases(&current->sighand->siglock)
+{
+	spin_unlock_irq(&current->sighand->siglock);
+}
+#else
+static inline void sigaltstack_lock(void) { }
+static inline void sigaltstack_unlock(void) { }
+#endif
+
 static int
 do_sigaltstack (const stack_t *ss, stack_t *oss, unsigned long sp,
 		size_t min_ss_size)
 {
 	struct task_struct *t = current;
+	int ret = 0;
 
 	if (oss) {
 		memset(oss, 0, sizeof(stack_t));
@@ -4038,19 +4056,24 @@ do_sigaltstack (const stack_t *ss, stack_t *oss, unsigned long sp,
 				ss_mode != 0))
 			return -EINVAL;
 
+		sigaltstack_lock();
 		if (ss_mode == SS_DISABLE) {
 			ss_size = 0;
 			ss_sp = NULL;
 		} else {
 			if (unlikely(ss_size < min_ss_size))
-				return -ENOMEM;
+				ret = -ENOMEM;
+			if (!sigaltstack_size_valid(ss_size))
+				ret = -ENOMEM;
 		}
-
-		t->sas_ss_sp = (unsigned long) ss_sp;
-		t->sas_ss_size = ss_size;
-		t->sas_ss_flags = ss_flags;
+		if (!ret) {
+			t->sas_ss_sp = (unsigned long) ss_sp;
+			t->sas_ss_size = ss_size;
+			t->sas_ss_flags = ss_flags;
+		}
+		sigaltstack_unlock();
 	}
-	return 0;
+	return ret;
 }
 
 SYSCALL_DEFINE2(sigaltstack,const stack_t __user *,uss, stack_t __user *,uoss)