[tor-commits] [tor/master] Avoid unsigned integer underflow on empty input.

[nickm at torproject.org]

commit a17dc0875ad0d434d9cf66d36ed23fbd69286bf3
Author: Nick Mathewson <nickm at torproject.org>
Date:   Mon May 7 13:56:39 2018 -0400

    Avoid unsigned integer underflow on empty input.
---
 src/or/dirserv.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/or/dirserv.c b/src/or/dirserv.c
index d9a9b8522..e47533759 100644
--- a/src/or/dirserv.c
+++ b/src/or/dirserv.c
@@ -2641,6 +2641,12 @@ measured_bw_line_parse(measured_bw_line_t *out, const char *orig_line)
   int got_node_id = 0;
   char *strtok_state; /* lame sauce d'jour */
 
+  if (strlen(line) == 0) {
+    log_warn(LD_DIRSERV, "Empty line in bandwidth file");
+    tor_free(line);
+    return -1;
+  }
+
   /* Remove end of line character, so that is not part of the token */
   if (line[strlen(line) - 1] == '\n') {
     line[strlen(line) - 1] = '\0';