1 files changed, 43 insertions, 2 deletions

diff --git a/fs/compat.c b/fs/compat.c
index d0145ca27572..55efdfebdf5a 100644
--- a/fs/compat.c
+++ b/fs/compat.c
@@ -378,6 +378,34 @@ out:
         return error;
 }
 
+/*
+ * This is a copy of sys_ustat, just dealing with a structure layout.
+ * Given how simple this syscall is that apporach is more maintainable
+ * than the various conversion hacks.
+ */
+asmlinkage long compat_sys_ustat(unsigned dev, struct compat_ustat __user *u)
+{
+        struct super_block *sb;
+        struct compat_ustat tmp;
+        struct kstatfs sbuf;
+        int err;
+
+        sb = user_get_super(new_decode_dev(dev));
+        if (!sb)
+                return -EINVAL;
+        err = vfs_statfs(sb->s_root, &sbuf);
+        drop_super(sb);
+        if (err)
+                return err;
+
+        memset(&tmp, 0, sizeof(struct compat_ustat));
+        tmp.f_tfree = sbuf.f_bfree;
+        tmp.f_tinode = sbuf.f_ffree;
+        if (copy_to_user(u, &tmp, sizeof(struct compat_ustat)))
+                return -EFAULT;
+        return 0;
+}
+
 static int get_compat_flock(struct flock *kfl, struct compat_flock __user *ufl)
 {
         if (!access_ok(VERIFY_READ, ufl, sizeof(*ufl)) ||
@@ -1392,22 +1420,28 @@ int compat_do_execve(char * filename,
 {
         struct linux_binprm *bprm;
         struct file *file;
+        struct files_struct *displaced;
         int retval;
 
+        retval = unshare_files(&displaced);
+        if (retval)
+                goto out_ret;
+
         retval = -ENOMEM;
         bprm = kzalloc(sizeof(*bprm), GFP_KERNEL);
         if (!bprm)
-                goto out_ret;
+                goto out_files;
 
         retval = mutex_lock_interruptible(&current->cred_exec_mutex);
         if (retval < 0)
                 goto out_free;
+        current->in_execve = 1;
 
         retval = -ENOMEM;
         bprm->cred = prepare_exec_creds();
         if (!bprm->cred)
                 goto out_unlock;
-        check_unsafe_exec(bprm, current->files);
+        check_unsafe_exec(bprm);
 
         file = open_exec(filename);
         retval = PTR_ERR(file);
@@ -1454,9 +1488,12 @@ int compat_do_execve(char * filename,
                 goto out;
 
         /* execve succeeded */
+        current->in_execve = 0;
         mutex_unlock(&current->cred_exec_mutex);
         acct_update_integrals(current);
         free_bprm(bprm);
+        if (displaced)
+                put_files_struct(displaced);
         return retval;
 
 out:
@@ -1470,11 +1507,15 @@ out_file:
         }
 
 out_unlock:
+        current->in_execve = 0;
         mutex_unlock(&current->cred_exec_mutex);
 
 out_free:
         free_bprm(bprm);
 
+out_files:
+        if (displaced)
+                reset_files_struct(displaced);
 out_ret:
         return retval;
 }