exec: Fix check for | and |&

These are only allowed as separate args. One check was allowing
them as a prefix which could lead to an invalid memory access

Reported-by: Ryan Whitworth <me@ryanwhitworth.com>
Signed-off-by: Steve Bennett <steveb@workware.net.au>

2 files changed, 10 insertions, 4 deletions

diff --git a/jim-exec.c b/jim-exec.c
index dac8ade..125f41a 100644
--- a/jim-exec.c
+++ b/jim-exec.c
@@ -959,10 +959,11 @@ badargs:
         fdtype origErrorId = errorId;
 
         for (lastArg = firstArg; lastArg < arg_count; lastArg++) {
-            if (arg_array[lastArg][0] == '|') {
-                if (arg_array[lastArg][1] == '&') {
-                    pipe_dup_err = 1;
-                }
+            if (strcmp(arg_array[lastArg], "|") == 0) {
+                break;
+            }
+            if (strcmp(arg_array[lastArg], "|&") == 0) {
+                pipe_dup_err = 1;
                 break;
             }
         }
diff --git a/regtest.tcl b/regtest.tcl
index 5bc3227..7b67586 100644
--- a/regtest.tcl
+++ b/regtest.tcl
@@ -300,6 +300,11 @@ puts "TEST 40 PASSED"
 catch {scan x %3}
 puts "TEST 41 PASSED"
 
+# REGTEST 42
+# | and |& are not acceptable as prefixes
+catch {exec dummy |x second}
+puts "TEST 42 PASSED"
+
 # TAKE THE FOLLOWING puts AS LAST LINE
 
 puts "--- ALL TESTS PASSED ---"