Commit 9d077783 authored by Nick Mathewson's avatar Nick Mathewson 🦀
Browse files

Add a fix for the buf_pullup bug that Vektor reported

parent ff2c9acb

changes/buffer_bug

0 → 100644
+7 −0
Original line number Diff line number Diff line 


  o Major bugfixes:

    - Fix a heap overflow bug that could occur when trying to pull

      data into the first chunk of a buffer, when that chunk had

      already had some data drained from it. Fixes CVE-2011-2778;

      bugfix on 0.2.0.16-alpha. Reported by "Vektor".

src/or/buffers.c

+3 −2
Original line number Diff line number Diff line
@@ -375,9 +375,10 @@ buf_pullup(buf_t *buf, size_t bytes, int nulterminate) 


  if (buf->head->memlen >= capacity) {

    /* We don't need to grow the first chunk, but we might need to repack it.*/

    if (CHUNK_REMAINING_CAPACITY(buf->head) < capacity-buf->datalen)

    size_t needed = capacity - buf->head->datalen;

    if (CHUNK_REMAINING_CAPACITY(buf->head) < needed)

      chunk_repack(buf->head);

    tor_assert(CHUNK_REMAINING_CAPACITY(buf->head) >= capacity-buf->datalen);

    tor_assert(CHUNK_REMAINING_CAPACITY(buf->head) >= needed);

  } else {

    chunk_t *newhead;

    size_t newsize;