dc: Parse error & fix out of bounds read in xc_program_printString
function old new delta
xc_program_print 712 735 +23
Signed-off-by: Brian Foley <bpfoley@google.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/miscutils/bc.c b/miscutils/bc.c
index 016300a..e492f0f 100644
--- a/miscutils/bc.c
+++ b/miscutils/bc.c
@@ -5456,11 +5456,13 @@
char *n;
c = *str++;
- n = strchr(esc, c); // note: c can be NUL
- if (!n) {
+ n = strchr(esc, c); // note: if c is NUL, n = \0 at end of esc
+ if (!n || !c) {
// Just print the backslash and following character
bb_putchar('\\');
++G.prog.nchars;
+ // But if we're at the end of the string, stop
+ if (!c) break;
} else {
if (n - esc == 0) // "\n" ?
G.prog.nchars = SIZE_MAX;
diff --git a/testsuite/dc.tests b/testsuite/dc.tests
index 1fc13c2..361bc84 100755
--- a/testsuite/dc.tests
+++ b/testsuite/dc.tests
@@ -59,6 +59,26 @@
"42\n" \
"" ""
+testing "dc: p should print invalid escapes" \
+ "dc -e '[\q] p'" \
+ "\\q\n" \
+ "" ""
+
+testing "dc: p should print trailing backslashes" \
+ "dc -e '[q\] p'" \
+ "q\\\\\n" \
+ "" ""
+
+testing "dc: p should parse/print single backslashes" \
+ "dc -e '[\] p'" \
+ "\\\\\n" \
+ "" ""
+
+testing "dc: p should print single backslash strings" \
+ "dc -e '92 a p'" \
+ "\\\\\n" \
+ "" ""
+
testing "dc read" \
"dc -finput" \
"2\n9\n1\n" \
