# HG changeset patch
# User Christian Brabandt <cb@256bit.org>
# Date 1700169315 -3600
# Node ID 872c07d5befe549c18d8ff37e851f483112cee7e
# Parent  682386b2c209b55c985b15623bad13367b082c0c
patch 9.0.2112: [security]: overflow in shift_line

Commit: https://github.com/vim/vim/commit/6bf131888a3d1de62bbfa8a7ea03c0ddccfd496e
Author: Christian Brabandt <cb@256bit.org>
Date:   Tue Nov 14 22:42:59 2023 +0100

    patch 9.0.2112: [security]: overflow in shift_line

    Problem:  [security]: overflow in shift_line
    Solution: allow a max indent of INT_MAX

    [security]: overflow in shift_line

    When shifting lines in operator pending mode and using a very large
    value, we may overflow the size of integer. Fix this by using a long
    variable, testing if the result would be larger than INT_MAX and if so,
    indent by INT_MAX value.

    Special case: We cannot use long here, since on 32bit architectures (or
    on Windows?), it typically cannot take larger values than a plain int,
    so we have to use long long count, decide whether the resulting
    multiplication of the shiftwidth value * amount is larger than INT_MAX
    and if so, we will store INT_MAX as possible larges value in the long
    long count variable.

    Then we can safely cast it back to int when calling the functions to set
    the indent (set_indent() or change_indent()). So this should be safe.

    Add a test that when using a huge value in operator pending mode for
    shifting, we will shift by INT_MAX

    closes: #13535

    Signed-off-by: Christian Brabandt <cb@256bit.org>

diff --git a/src/ops.c b/src/ops.c
--- a/src/ops.c
+++ b/src/ops.c
@@ -229,11 +229,11 @@ shift_line(
     int	amount,
     int call_changed_bytes)	// call changed_bytes()
 {
-    int		count;
+    long long	count;
     int		i, j;
     int		sw_val = (int)get_sw_value_indent(curbuf);
 
-    count = get_indent();	// get current indent
+    count = (long long)get_indent();	// get current indent
 
     if (round)			// round off indent
     {
@@ -260,14 +260,19 @@ shift_line(
 		count = 0;
 	}
 	else
-	    count += sw_val * amount;
+	{
+	    if ((long long)sw_val * (long long)amount > INT_MAX - count)
+		count = INT_MAX;
+	    else
+		count += (long long)sw_val * (long long)amount;
+	}
     }
 
     // Set new indent
     if (State & VREPLACE_FLAG)
-	change_indent(INDENT_SET, count, FALSE, NUL, call_changed_bytes);
+	change_indent(INDENT_SET, (int)count, FALSE, NUL, call_changed_bytes);
     else
-	(void)set_indent(count, call_changed_bytes ? SIN_CHANGED : 0);
+	(void)set_indent((int)count, call_changed_bytes ? SIN_CHANGED : 0);
 }
 
 /*
diff --git a/src/testdir/test_indent.vim b/src/testdir/test_indent.vim
--- a/src/testdir/test_indent.vim
+++ b/src/testdir/test_indent.vim
@@ -275,4 +275,15 @@ func Test_formatting_keeps_first_line_in
   bwipe!
 endfunc
 
+" Test for indenting with large amount, causes overflow
+func Test_indent_overflow_count()
+  new
+  setl sw=8
+  call setline(1, "abc")
+  norm! V2147483647>
+  " indents by INT_MAX
+  call assert_equal(2147483647, indent(1))
+  close!
+endfunc
+
 " vim: shiftwidth=2 sts=2 expandtab
diff --git a/src/version.c b/src/version.c
--- a/src/version.c
+++ b/src/version.c
@@ -705,6 +705,8 @@ static char *(features[]) =
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2112,
+/**/
     2111,
 /**/
     2110,