[trafficserver] branch master updated: CacheVC::openWriteCloseDir: fix metric array indexing (#10682)

[bneradt]

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bneradt pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/trafficserver.git


The following commit(s) were added to refs/heads/master by this push:
     new edf70d4002 CacheVC::openWriteCloseDir: fix metric array indexing 
(#10682)
edf70d4002 is described below

commit edf70d4002c893e8d8ea40e74a03ca7ab8975d10
Author: Brian Neradt <brian.ner...@gmail.com>
AuthorDate: Thu Oct 26 15:30:18 2023 -0500

    CacheVC::openWriteCloseDir: fix metric array indexing (#10682)
    
    The fragment_document_count is an array of size 3. Our logic for
    accessing it was supposed to clamp indexing into it between values
    0 through 2, but accidentally allowed indexing outside of that range.
    This resulted in an out of bounds index into random memory. This fixes
    the logic to properly clamp to the appropriate values.
    
    For reference here's the old logic before our recent Metrics change:
    
https://github.com/apache/trafficserver/pull/10175/files#diff-6ac65bcc29d9196567a0bbff3c7aa6705ebb7a6041f4a5706b6b475202d4934dL1200
---
 src/iocore/cache/CacheWrite.cc | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/iocore/cache/CacheWrite.cc b/src/iocore/cache/CacheWrite.cc
index 7ce268bbf4..6183816818 100644
--- a/src/iocore/cache/CacheWrite.cc
+++ b/src/iocore/cache/CacheWrite.cc
@@ -1048,8 +1048,8 @@ CacheVC::openWriteCloseDir(int /* event ATS_UNUSED */, 
Event * /* e ATS_UNUSED *
   if ((closed == 1) && (total_len > 0 || f.allow_empty_doc)) {
     DDbg(dbg_ctl_cache_stats, "Fragment = %d", fragment);
 
-    Metrics::increment(cache_rsb.fragment_document_count[std::max(fragment, 
2)]);
-    
Metrics::increment(vol->cache_vol->vol_rsb.fragment_document_count[std::max(fragment,
 2)]);
+    Metrics::increment(cache_rsb.fragment_document_count[std::clamp(fragment, 
0, 2)]);
+    
Metrics::increment(vol->cache_vol->vol_rsb.fragment_document_count[std::clamp(fragment,
 0, 2)]);
   }
   if (f.close_complete) {
     recursive++;