Add a comment about CID 1311630 and why we won't worry about it.

diff --git a/src/ext/ed25519/donna/modm-donna-64bit.h b/src/ext/ed25519/donna/modm-donna-64bit.h
index b22df2be75e830320affedd9799916a785b80ffb..012ea9ea0845f21650bc35b01b46200d1e096082 100644 (file)
--- a/src/ext/ed25519/donna/modm-donna-64bit.h
+++ b/src/ext/ed25519/donna/modm-donna-64bit.h
@@ -261,6 +261,10 @@ contract256_slidingwindow_modm(signed char r[256], const bignum256modm s, int wi
                        continue;
 
                for (b = 1; (b < (soplen - j)) && (b <= 6); b++) {
+                       /* XXX Tor: coverity scan says that r[j+b] can
+                        * overflow, but that's not possible: b < (soplen-j)
+                        * guarantees that b + j < soplen, so b+j < 256,
+                        * so the index doesn't overflow. */
                        if ((r[j] + (r[j + b] << b)) <= m) {
                                r[j] += r[j + b] << b;
                                r[j + b] = 0;