Preempt-safe RCU file usage

Fix up fs/compat.c fixes.

1 files changed, 2 insertions, 0 deletions

diff --git a/fs/compat.c b/fs/compat.c
index c2e0813164b4..ac3fb9ed8eea 100644
--- a/fs/compat.c
+++ b/fs/compat.c
@@ -1645,8 +1645,10 @@ compat_sys_select(int n, compat_ulong_t __user *inp, compat_ulong_t __user *outp
                 goto out_nofds;
 
         /* max_fdset can increase, so grab it once to avoid race */
+        rcu_read_lock();
         fdt = files_fdtable(current->files);
         max_fdset = fdt->max_fdset;
+        rcu_read_unlock();
         if (n > max_fdset)
                 n = max_fdset;