2 files changed, 6 insertions, 0 deletions

diff --git a/include/linux/swap.h b/include/linux/swap.h
index b86b5c20617d..8dc0ea7caf02 100644
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -21,6 +21,9 @@ struct bio;
 #define SWAP_FLAG_PRIO_SHIFT    0
 #define SWAP_FLAG_DISCARD       0x10000 /* discard swap cluster after use */
 
+#define SWAP_FLAGS_VALID        (SWAP_FLAG_PRIO_MASK | SWAP_FLAG_PREFER | \
+                                 SWAP_FLAG_DISCARD)
+
 static inline int current_is_kswapd(void)
 {
         return current->flags & PF_KSWAPD;
diff --git a/mm/swapfile.c b/mm/swapfile.c
index dae42f380d6e..fafc26d1b1dc 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -2022,6 +2022,9 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags)
         struct page *page = NULL;
         struct inode *inode = NULL;
 
+        if (swap_flags & ~SWAP_FLAGS_VALID)
+                return -EINVAL;
+
         if (!capable(CAP_SYS_ADMIN))
                 return -EPERM;