File e63d7cdf.patch of Package busybox.26988
From e63d7cdfdac78c6fd27e9e63150335767592b85e Mon Sep 17 00:00:00 2001
From: Natanael Copa <ncopa@alpinelinux.org>
Date: Fri, 17 Jun 2022 17:45:34 +0200
Subject: [PATCH] awk: fix use after free (CVE-2022-30065)
fixes https://bugs.busybox.net/show_bug.cgi?id=14781
function old new delta
evaluate 3343 3357 +14
Signed-off-by: Natanael Copa <ncopa@alpinelinux.org>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
---
editors/awk.c | 3 +++
testsuite/awk.tests | 6 ++++++
2 files changed, 9 insertions(+)
Index: busybox-1.35.0/editors/awk.c
===================================================================
--- busybox-1.35.0.orig/editors/awk.c
+++ busybox-1.35.0/editors/awk.c
@@ -3114,6 +3114,9 @@ static var *evaluate(node *op, var *res)
case XC( OC_MOVE ):
debug_printf_eval("MOVE\n");
+ /* make sure that we never return a temp var */
+ if (L.v == TMPVAR0)
+ L.v = res;
/* if source is a temporary string, jusk relink it to dest */
if (R.v == TMPVAR1
&& !(R.v->type & VF_NUMBER)
Index: busybox-1.35.0/testsuite/awk.tests
===================================================================
--- busybox-1.35.0.orig/testsuite/awk.tests
+++ busybox-1.35.0/testsuite/awk.tests
@@ -469,4 +469,10 @@ testing 'awk printf %% prints one %' \
"%\n" \
'' ''
+testing 'awk assign while test' \
+ "awk '\$1==\$1=\"foo\" {print \$1}'" \
+ "foo\n" \
+ "" \
+ "foo"
+
exit $FAILCOUNT
