[tor-commits] [tor/release-0.4.2] Change BUG() messages in buf_flush_to_tls() to IF_BUG_ONCE()

[nickm at torproject.org]

commit 1f163fcbde4591bcb5764d6bbe0fea8aa559fc33
Author: Nick Mathewson <nickm at torproject.org>
Date:   Wed Jan 29 08:31:22 2020 -0500

    Change BUG() messages in buf_flush_to_tls() to IF_BUG_ONCE()
    
    We introduced these BUG() checks in b0ddaac07428a06 to prevent a
    recurrence of bug 23690.  But there's a report of the BUG() message
    getting triggered and filling up the disk.  Let's change it to
    IF_BUG_ONCE().
    
    Fixes bug 33093; bugfix on 0.3.2.2-alpha.
---
 changes/bug33093_logging  | 5 +++++
 src/lib/tls/buffers_tls.c | 4 ++--
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/changes/bug33093_logging b/changes/bug33093_logging
new file mode 100644
index 000000000..e26e4a64a
--- /dev/null
+++ b/changes/bug33093_logging
@@ -0,0 +1,5 @@
+  o Minor bugfixes (logging):
+    - If we encounter a bug when flushing a buffer to a TLS connection,
+      only log the bug once per invocation of the Tor process.  Previously we
+      would log with every occurrence, which could cause us to run out of
+      disk space.  Fixes bug 33093; bugfix on 0.3.2.2-alpha.
diff --git a/src/lib/tls/buffers_tls.c b/src/lib/tls/buffers_tls.c
index e92cb9163..b570216df 100644
--- a/src/lib/tls/buffers_tls.c
+++ b/src/lib/tls/buffers_tls.c
@@ -146,10 +146,10 @@ buf_flush_to_tls(buf_t *buf, tor_tls_t *tls, size_t flushlen,
   size_t flushed = 0;
   ssize_t sz;
   tor_assert(buf_flushlen);
-  if (BUG(*buf_flushlen > buf->datalen)) {
+  IF_BUG_ONCE(*buf_flushlen > buf->datalen) {
     *buf_flushlen = buf->datalen;
   }
-  if (BUG(flushlen > *buf_flushlen)) {
+  IF_BUG_ONCE(flushlen > *buf_flushlen) {
     flushlen = *buf_flushlen;
   }
   sz = (ssize_t) flushlen;