commit 3eb1637b1bba19519885dd6d377bd5596e91d22c
Author: Bram Moolenaar <Bram@vim.org>
Date:   Sun Feb 26 18:11:36 2017 +0100

    patch 8.0.0377: possible overflow when reading corrupted undo file
    
    Problem:    Possible overflow when reading corrupted undo file.
    Solution:   Check if allocated size is not too big. (King)

diff --git a/src/undo.c b/src/undo.c
index b69f31872..ba7c0b83c 100644
--- a/src/undo.c
+++ b/src/undo.c
@@ -1836,7 +1836,7 @@ u_read_undo(char_u *name, char_u *hash, char_u *orig_name)
     linenr_T	line_lnum;
     colnr_T	line_colnr;
     linenr_T	line_count;
-    int		num_head = 0;
+    long	num_head = 0;
     long	old_header_seq, new_header_seq, cur_header_seq;
     long	seq_last, seq_cur;
     long	last_save_nr = 0;
@@ -2023,7 +2023,8 @@ u_read_undo(char_u *name, char_u *hash, char_u *orig_name)
      * When there are no headers uhp_table is NULL. */
     if (num_head > 0)
     {
-	uhp_table = (u_header_T **)U_ALLOC_LINE(
+	if (num_head < LONG_MAX / (long)sizeof(u_header_T *))
+	    uhp_table = (u_header_T **)U_ALLOC_LINE(
 					     num_head * sizeof(u_header_T *));
 	if (uhp_table == NULL)
 	    goto error;
diff --git a/src/version.c b/src/version.c
index 76eb529..f3832b2 100644
--- a/src/version.c
+++ b/src/version.c
@@ -740,6 +740,8 @@ static int included_patches[] =
  */
 static char *(extra_patches[]) =
 {   /* Add your patch description below this line */
+/**/
+    "8.0.0377",
 /**/
     "8.0.0056",
 /**/