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From 3079f7966dbed4497e36d5067cbfd896a90358cb Mon Sep 17 00:00:00 2001
From: Cyrill Gorcunov <gorcunov@gmail.com>
Date: Wed, 14 Nov 2018 10:03:42 +0300
Subject: [PATCH] preproc: Fix malformed parameter count
readnum returns 64bit number which may become
a negative integer upon conversion which in
turn lead to out of bound array access.
Fix it by explicit conversion with bounds check
| POC6:2: error: parameter count `2222222222' is out of bounds [0; 2147483647]
https://bugzilla.nasm.us/show_bug.cgi?id=3392528
Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
Upstream-Status: Backport
CVE: CVE-2018-19755
Signed-off-by: Anuj Mittal <anuj.mittal@intel.com>
---
asm/preproc.c | 43 +++++++++++++++++++++----------------------
1 file changed, 21 insertions(+), 22 deletions(-)
diff --git a/asm/preproc.c b/asm/preproc.c
index b6afee3..e5ad05a 100644
--- a/asm/preproc.c
+++ b/asm/preproc.c
@@ -1650,6 +1650,23 @@ smacro_defined(Context * ctx, const char *name, int nparam, SMacro ** defn,
return false;
}
+/* param should be a natural number [0; INT_MAX] */
+static int read_param_count(const char *str)
+{
+ int result;
+ bool err;
+
+ result = readnum(str, &err);
+ if (result < 0 || result > INT_MAX) {
+ result = 0;
+ nasm_error(ERR_NONFATAL, "parameter count `%s' is out of bounds [%d; %d]",
+ str, 0, INT_MAX);
+ } else if (err) {
+ nasm_error(ERR_NONFATAL, "unable to parse parameter count `%s'", str);
+ }
+ return result;
+}
+
/*
* Count and mark off the parameters in a multi-line macro call.
* This is called both from within the multi-line macro expansion
@@ -1871,11 +1888,7 @@ static bool if_condition(Token * tline, enum preproc_token ct)
pp_directives[ct]);
} else {
searching.nparam_min = searching.nparam_max =
- readnum(tline->text, &j);
- if (j)
- nasm_error(ERR_NONFATAL,
- "unable to parse parameter count `%s'",
- tline->text);
+ read_param_count(tline->text);
}
if (tline && tok_is_(tline->next, "-")) {
tline = tline->next->next;
@@ -1886,11 +1899,7 @@ static bool if_condition(Token * tline, enum preproc_token ct)
"`%s' expects a parameter count after `-'",
pp_directives[ct]);
else {
- searching.nparam_max = readnum(tline->text, &j);
- if (j)
- nasm_error(ERR_NONFATAL,
- "unable to parse parameter count `%s'",
- tline->text);
+ searching.nparam_max = read_param_count(tline->text);
if (searching.nparam_min > searching.nparam_max) {
nasm_error(ERR_NONFATAL,
"minimum parameter count exceeds maximum");
@@ -2079,8 +2088,6 @@ static void undef_smacro(Context *ctx, const char *mname)
*/
static bool parse_mmacro_spec(Token *tline, MMacro *def, const char *directive)
{
- bool err;
-
tline = tline->next;
skip_white_(tline);
tline = expand_id(tline);
@@ -2103,11 +2110,7 @@ static bool parse_mmacro_spec(Token *tline, MMacro *def, const char *directive)
if (!tok_type_(tline, TOK_NUMBER)) {
nasm_error(ERR_NONFATAL, "`%s' expects a parameter count", directive);
} else {
- def->nparam_min = def->nparam_max =
- readnum(tline->text, &err);
- if (err)
- nasm_error(ERR_NONFATAL,
- "unable to parse parameter count `%s'", tline->text);
+ def->nparam_min = def->nparam_max = read_param_count(tline->text);
}
if (tline && tok_is_(tline->next, "-")) {
tline = tline->next->next;
@@ -2117,11 +2120,7 @@ static bool parse_mmacro_spec(Token *tline, MMacro *def, const char *directive)
nasm_error(ERR_NONFATAL,
"`%s' expects a parameter count after `-'", directive);
} else {
- def->nparam_max = readnum(tline->text, &err);
- if (err) {
- nasm_error(ERR_NONFATAL, "unable to parse parameter count `%s'",
- tline->text);
- }
+ def->nparam_max = read_param_count(tline->text);
if (def->nparam_min > def->nparam_max) {
nasm_error(ERR_NONFATAL, "minimum parameter count exceeds maximum");
def->nparam_max = def->nparam_min;
--
2.10.5.GIT
|
