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
index c0a2981..ecd7fc2 100644
--- a/src/ops.c
+++ b/src/ops.c
@@ -229,11 +229,11 @@
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 @@
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
index 96e9d23..217a7ae 100644
--- a/src/testdir/test_indent.vim
+++ b/src/testdir/test_indent.vim
@@ -275,4 +275,15 @@
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
index 66aff80..249cd11 100644
--- a/src/version.c
+++ b/src/version.c
@@ -705,6 +705,8 @@
static int included_patches[] =
{ /* Add new patch number below this line */
/**/
+ 2112,
+/**/
2111,
/**/
2110,