[PATCH] vim: fix 2021-3796

[Minjae Kim <flowergom@gmail.com>]

vim is vulnerable to Use After Free
Problem:    Checking first character of url twice.

reference:
https://github.com/vim/vim/commit/35a9a00afcb20897d462a766793ff45534810dc3
---
 .../vim/files/CVE-2021-3796.patch             | 70 +++++++++++++++++++
 meta/recipes-support/vim/vim.inc              |  3 +-
 2 files changed, 72 insertions(+), 1 deletion(-)
 create mode 100644 meta/recipes-support/vim/files/CVE-2021-3796.patch

diff --git a/meta/recipes-support/vim/files/CVE-2021-3796.patch b/meta/recipes-support/vim/files/CVE-2021-3796.patch
new file mode 100644
index 0000000000..08becb4d9a
--- /dev/null
+++ b/meta/recipes-support/vim/files/CVE-2021-3796.patch
@@ -0,0 +1,70 @@
+From 296bf20889e66e3235e199838c6e360db2c4166d Mon Sep 17 00:00:00 2001
+From: Minjae Kim <flowergom@gmail.com>
+Date: Fri, 22 Oct 2021 02:24:32 +0000
+Subject: [PATCH] patch 8.2.3428: using freed memory when replacing
+
+Problem:    Using freed memory when replacing. (Dhiraj Mishra)
+Solution:   Get the line pointer after calling ins_copychar().
+
+Upstream-Status: Accepted [https://github.com/vim/vim/commit/35a9a00afcb20897d462a766793ff45534810dc3]
+CVE: CVE-2021-3796
+Signed-off-by: Minjae Kim <flowergom@gmail.com>
+---
+ src/normal.c              | 11 +++++++----
+ src/testdir/test_edit.vim | 12 ++++++++++++
+ 2 files changed, 19 insertions(+), 4 deletions(-)
+
+diff --git a/src/normal.c b/src/normal.c
+index c4963e621..277c92595 100644
+--- a/src/normal.c
++++ b/src/normal.c
+@@ -5009,19 +5009,22 @@ nv_replace(cmdarg_T *cap)
+           {
+               /*
+                * Get ptr again, because u_save and/or showmatch() will have
+-               * released the line.  At the same time we let know that the
++               * released the line. This may also happen in ins_copychar().
++               * At the same time we let know that the
+                * line will be changed.
+                */
+-              ptr = ml_get_buf(curbuf, curwin->w_cursor.lnum, TRUE);
+               if (cap->nchar == Ctrl_E || cap->nchar == Ctrl_Y)
+               {
+                 int c = ins_copychar(curwin->w_cursor.lnum
+                                          + (cap->nchar == Ctrl_Y ? -1 : 1));
++
++                ptr = ml_get_buf(curbuf, curwin->w_cursor.lnum, TRUE);
+                 if (c != NUL)
+                   ptr[curwin->w_cursor.col] = c;
+-              }
+-              else
++              } else {
+                   ptr[curwin->w_cursor.col] = cap->nchar;
++                  ptr = ml_get_buf(curbuf, curwin->w_cursor.lnum, TRUE);
++              }
+               if (p_sm && msg_silent == 0)
+                   showmatch(cap->nchar);
+               ++curwin->w_cursor.col;
+diff --git a/src/testdir/test_edit.vim b/src/testdir/test_edit.vim
+index 4e29e7fe1..d7565e1ea 100644
+--- a/src/testdir/test_edit.vim
++++ b/src/testdir/test_edit.vim
+@@ -1519,3 +1519,15 @@ func Test_edit_noesckeys()
+   bwipe!
+   set esckeys
+ endfunc
++
++" Test for getting the character of the line below after "p"
++func Test_edit_put_CTRL_E()
++  set encoding=latin1
++  new
++  let @" = ''
++  sil! norm orggRx
++  sil! norm pr
++  call assert_equal(['r', 'r'], getline(1, 2))
++  bwipe!
++  set encoding=utf-8
++endfunc
+-- 
+2.17.1
+
diff --git a/meta/recipes-support/vim/vim.inc b/meta/recipes-support/vim/vim.inc
index db1e9caf4d..917f82404b 100644
--- a/meta/recipes-support/vim/vim.inc
+++ b/meta/recipes-support/vim/vim.inc
@@ -18,7 +18,8 @@ SRC_URI = "git://github.com/vim/vim.git \
            file://no-path-adjust.patch \
            file://racefix.patch \
            file://b7081e135a16091c93f6f5f7525a5c58fb7ca9f9.patch \
-          file://CVE-2021-3778.patch \
+           file://CVE-2021-3778.patch \
+          file://CVE-2021-3796.patch \
 "
 
 SRCREV = "98056533b96b6b5d8849641de93185dd7bcadc44"
-- 
2.30.1 (Apple Git-130)