next_pidmap: fix overflow condition

[pandora-kernel.git] / kernel / pid.c

diff --git a/kernel/pid.c b/kernel/pid.c
index 02f2212..57a8346 100644 (file)
--- 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];