[MODPYTHON-182] Memory leak in request readline()

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.2.x, 3.3.x, 3.2.10
• Fix Version/s: 3.3.1
• Component/s: core
• Environment: Apache 2.0.55 mpm-worker
• Assignee: James Paul Gallacher
• Reporter: James Paul Gallacher
• Created: 11/Aug/06 20:49
• Updated: 01/May/07 10:39
• Resolved: 17/Sep/06 12:33

Description

There is at least one memory leak request.readline(). I'm currently auditing the code so there may well be others.

I think the leak will only occur when the request body is incompletely read with readline, which is likely an unusual corner case. The following demostrates the leak:

Consider a request body consisting of:

'\n'.join([ 'a'*100 for i in xrange(0, 100) ])

and using this handler:

def handler(req):

1. Handler reads 20 lines but request contains 100 lines.
2. Since the body is not completely read, the buffer allocated
3. in requestobject.c req_readline is never freed.
   req.content_type = 'text/plain'
   count = 0
   for i in range(0, 20):
   line = req.readline()
   count += 1

req.write('ok readline_partial: %d lines read' % count)
return apache.OK

With this test setup I'm seeing a leak of approx 10k bytes per request.