Address review comments.

Author: serhiy-storchaka

Lib/http/client.py

@@ -113,7 +113,7 @@
 
 # Data larger than this will be read in chunks, to prevent extreme
 # overallocation.
-_SAFE_BUF_SIZE = 1 << 20
+_MIN_READ_BUF_SIZE = 1 << 20
 
 
 # Header name/value ABNF (http://tools.ietf.org/html/rfc7230#section-3.2)
@@ -647,11 +647,13 @@ def _safe_read(self, amt):
         reading. If the bytes are truly not available (due to EOF), then the
         IncompleteRead exception can be used to detect the problem.
         """
-        cursize = min(amt, _SAFE_BUF_SIZE)
+        cursize = min(amt, _MIN_READ_BUF_SIZE)
         data = self.fp.read(cursize)
         while len(data) < amt:
             if len(data) < cursize:
                 raise IncompleteRead(data, amt-len(data))
+            # This is a geometric increase in read size (never more than
+            # doubling out the current length of data per loop iteration).
             delta = min(cursize, amt - cursize)
             data += self.fp.read(cursize)
             cursize += delta

Misc/NEWS.d/next/Security/2024-05-23-11-47-48.gh-issue-119451.qkJe9-.rst

@@ -1,6 +1,5 @@
-Fix a potential denial of service in the :mod:`http.client` module.
+Fix a potential memory denial of service in the :mod:`http.client` module.
 When connecting to a malicious server, it could cause
 an arbitrary amount of memory to be allocated.
-In best case this could lead to a :exc:`MemoryError` or other process crash.
-In worst case it could lead to swapping which would dramatically slow down the
-whole system and make it less responcible.
+This could have led to symptoms including a :exc:`MemoryError`, swapping, out
+of memory (OOM) killed processes or containers, or even system crashes.