1 files changed, 4 insertions, 1 deletions

diff --git a/kernel/pid.c b/kernel/pid.c
index 02f221274265..57a8346a270e 100644
--- a/kernel/pid.c
+++ b/kernel/pid.c
@@ -217,11 +217,14 @@ static int alloc_pidmap(struct pid_namespace *pid_ns)
         return -1;
 }
 
-int next_pidmap(struct pid_namespace *pid_ns, int last)
+int next_pidmap(struct pid_namespace *pid_ns, unsigned int last)
 {
         int offset;
         struct pidmap *map, *end;
 
+        if (last >= PID_MAX_LIMIT)
+                return -1;
+
         offset = (last + 1) & BITS_PER_PAGE_MASK;
         map = &pid_ns->pidmap[(last + 1)/BITS_PER_PAGE];
         end = &pid_ns->pidmap[PIDMAP_ENTRIES];