Commit 2985a601 authored by Nick Mathewson's avatar Nick Mathewson 🦀
Browse files

buf_read_from_tls: Return ERROR_MISC, not WANTWRITE, on BUG(). 

Fixes bug 32673; bugfix on 0.3.0.4-alpha.  We introduced these
checks in ee5471f9 to help diagnose 21369, but we used "-1"
when "TOR_TLS_ERROR_MISC" would have been correct.  Found by opara.

I don't think that this is actually getting triggered in the wild,
but if it were, it could cause nasty behavior: spurious
WANTREAD/WANTWRITE returns have a way of turning into CPU-eating
busy-loops.
parent 19954cff

changes/bug32673

0 → 100644
+5 −0
Original line number Diff line number Diff line 
  o Minor bugfixes (TLS bug handling):

    - When encountering a bug in buf_read_freom_tls(), return a

      "MISC" error code rather than "WANTWRITE".  This change might

      help avoid some CPU-wasting loops if the bug is ever triggered.

      Bug reported by opara.    Fixes bug 32673; bugfix on 0.3.0.4-alpha.

src/lib/tls/buffers_tls.c

+2 −2
Original line number Diff line number Diff line
@@ -69,9 +69,9 @@ buf_read_from_tls(buf_t *buf, tor_tls_t *tls, size_t at_most) 
  check_no_tls_errors();



  IF_BUG_ONCE(buf->datalen >= INT_MAX)

    return -1;

    return TOR_TLS_ERROR_MISC;

  IF_BUG_ONCE(buf->datalen >= INT_MAX - at_most)

    return -1;

    return TOR_TLS_ERROR_MISC;



  while (at_most > total_read) {

    size_t readlen = at_most - total_read;