diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index 4285f6adcc5eec7f7ca8998e2797d5a03c4c8009..6b16c36f0939313dde91d03428cdc855ff3dba9e 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -541,6 +541,7 @@ long do_arch_prctl(struct task_struct *task, int code, unsigned long addr)
 			load_gs_index(0);
 			ret = wrmsrl_safe(MSR_KERNEL_GS_BASE, addr);
 		}
+		put_cpu();
 		break;
 	case ARCH_SET_FS:
 		/* Not strictly needed for fs, but do it for symmetry