[Qemu-devel] [PATCH 06/10] vl.c: handle invalid NUMA CPU ranges properly

[Eduardo Habkost]

Add checks for the following cases:

* Empty string: will be ignored and won't set any CPU bitmap,
  parser won't abort.
* Missing end value after "-": parser will abort.
* Extra characters after a valid CPU range: parser will abort.
* "N-M" string where M < N: parser will abort.

Signed-off-by: Eduardo Habkost <address@hidden>
---
 vl.c | 24 +++++++++++++++++++++++-
 1 file changed, 23 insertions(+), 1 deletion(-)

diff --git a/vl.c b/vl.c
index 03a826e..19010fa 100644
--- a/vl.c
+++ b/vl.c
@@ -1057,13 +1057,30 @@ static void numa_node_parse_cpus(int nodenr, const char 
*cpus)
     char *endptr;
     unsigned long long value, endvalue;
 
+    /* Empty strings will be ignored, and not considered an error */
+    if (!*cpus) {
+        return;
+    }
+
     value = strtoull(cpus, &endptr, 10);
     if (*endptr == '-') {
-        endvalue = strtoull(endptr+1, &endptr, 10);
+        endptr++;
+        if (!*endptr) {
+            goto error;
+        }
+        endvalue = strtoull(endptr, &endptr, 10);
     } else {
         endvalue = value;
     }
 
+    if (*endptr != '\0')  {
+        goto error;
+    }
+
+    if (endvalue < value) {
+        goto error;
+    }
+
     if (!(endvalue < MAX_CPUMASK_BITS)) {
         endvalue = MAX_CPUMASK_BITS - 1;
         fprintf(stderr, "A max of %d CPUs are supported in a guest\n",
@@ -1071,6 +1088,11 @@ static void numa_node_parse_cpus(int nodenr, const char 
*cpus)
     }
 
     bitmap_set(node_cpumask[nodenr], value, endvalue-value+1);
+    return;
+
+error:
+    fprintf(stderr, "qemu: Invalid NUMA CPU range: %s\n", cpus);
+    exit(1);
 }
 
 static void numa_node_add(const char *optarg)
-- 
1.7.11.7