1 files changed, 24 insertions, 0 deletions

diff --git a/fs/nfs/proc.c b/fs/nfs/proc.c
index 03599bfe81cf..5c35b02857f3 100644
--- a/fs/nfs/proc.c
+++ b/fs/nfs/proc.c
@@ -598,6 +598,29 @@ nfs_proc_lock(struct file *filp, int cmd, struct file_lock *fl)
         return nlmclnt_proc(NFS_SERVER(inode)->nlm_host, cmd, fl);
 }
 
+/* Helper functions for NFS lock bounds checking */
+#define NFS_LOCK32_OFFSET_MAX ((__s32)0x7fffffffUL)
+static int nfs_lock_check_bounds(const struct file_lock *fl)
+{
+        __s32 start, end;
+
+        start = (__s32)fl->fl_start;
+        if ((loff_t)start != fl->fl_start)
+                goto out_einval;
+
+        if (fl->fl_end != OFFSET_MAX) {
+                end = (__s32)fl->fl_end;
+                if ((loff_t)end != fl->fl_end)
+                        goto out_einval;
+        } else
+                end = NFS_LOCK32_OFFSET_MAX;
+
+        if (start < 0 || start > end)
+                goto out_einval;
+        return 0;
+out_einval:
+        return -EINVAL;
+}
 
 const struct nfs_rpc_ops nfs_v2_clientops = {
         .version        = 2,                   /* protocol version */
@@ -633,4 +656,5 @@ const struct nfs_rpc_ops nfs_v2_clientops = {
         .file_open      = nfs_open,
         .file_release   = nfs_release,
         .lock           = nfs_proc_lock,
+        .lock_check_bounds = nfs_lock_check_bounds,
 };