Merge tag 'v3.7' into v4l_for_linus

Linux 3.7

* tag 'v3.7': (1545 commits)
  Linux 3.7
  Input: matrix-keymap - provide proper module license
  Revert "revert "Revert "mm: remove __GFP_NO_KSWAPD""" and associated damage
  ipv4: ip_check_defrag must not modify skb before unsharing
  Revert "mm: avoid waking kswapd for THP allocations when compaction is deferred or contended"
  inet_diag: validate port comparison byte code to prevent unsafe reads
  inet_diag: avoid unsafe and nonsensical prefix matches in inet_diag_bc_run()
  inet_diag: validate byte code to prevent oops in inet_diag_bc_run()
  inet_diag: fix oops for IPv4 AF_INET6 TCP SYN-RECV state
  mm: vmscan: fix inappropriate zone congestion clearing
  vfs: fix O_DIRECT read past end of block device
  net: gro: fix possible panic in skb_gro_receive()
  tcp: bug fix Fast Open client retransmission
  tmpfs: fix shared mempolicy leak
  mm: vmscan: do not keep kswapd looping forever due to individual uncompactable zones
  mm: compaction: validate pfn range passed to isolate_freepages_block
  mmc: sh-mmcif: avoid oops on spurious interrupts (second try)
  Revert misapplied "mmc: sh-mmcif: avoid oops on spurious interrupts"
  mmc: sdhci-s3c: fix missing clock for gpio card-detect
  lib/Makefile: Fix oid_registry build dependency
  ...

1 files changed, 25 insertions, 8 deletions

diff --git a/kernel/pid_namespace.c b/kernel/pid_namespace.c
index 478bad2745e3..7b07cc0dfb75 100644
--- a/kernel/pid_namespace.c
+++ b/kernel/pid_namespace.c
@@ -71,12 +71,22 @@ err_alloc:
         return NULL;
 }
 
+/* MAX_PID_NS_LEVEL is needed for limiting size of 'struct pid' */
+#define MAX_PID_NS_LEVEL 32
+
 static struct pid_namespace *create_pid_namespace(struct pid_namespace *parent_pid_ns)
 {
         struct pid_namespace *ns;
         unsigned int level = parent_pid_ns->level + 1;
-        int i, err = -ENOMEM;
+        int i;
+        int err;
+
+        if (level > MAX_PID_NS_LEVEL) {
+                err = -EINVAL;
+                goto out;
+        }
 
+        err = -ENOMEM;
         ns = kmem_cache_zalloc(pid_ns_cachep, GFP_KERNEL);
         if (ns == NULL)
                 goto out;
@@ -133,19 +143,26 @@ struct pid_namespace *copy_pid_ns(unsigned long flags, struct pid_namespace *old
         return create_pid_namespace(old_ns);
 }
 
-void free_pid_ns(struct kref *kref)
+static void free_pid_ns(struct kref *kref)
 {
-        struct pid_namespace *ns, *parent;
+        struct pid_namespace *ns;
 
         ns = container_of(kref, struct pid_namespace, kref);
-
-        parent = ns->parent;
         destroy_pid_namespace(ns);
+}
+
+void put_pid_ns(struct pid_namespace *ns)
+{
+        struct pid_namespace *parent;
 
-        if (parent != NULL)
-                put_pid_ns(parent);
+        while (ns != &init_pid_ns) {
+                parent = ns->parent;
+                if (!kref_put(&ns->kref, free_pid_ns))
+                        break;
+                ns = parent;
+        }
 }
-EXPORT_SYMBOL_GPL(free_pid_ns);
+EXPORT_SYMBOL_GPL(put_pid_ns);
 
 void zap_pid_ns_processes(struct pid_namespace *pid_ns)
 {