'Review Request 126507: Fix leaked file description and potential use-after-free in kdelibs4support'

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List:       kde-frameworks-devel
Subject:    Review Request 126507: Fix leaked file description and potential use-after-free in kdelibs4support
From:       "Michael Pyne" <mpyne () kde ! org>
Date:       2015-12-25 0:16:38
Message-ID: 20151225001638.29845.32135 () mimi ! kde ! org
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This is an automatically generated e-mail. To reply, visit:
https://git.reviewboard.kde.org/r/126507/
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Review request for KDE Frameworks.

Repository: kdelibs4support

Description
-------

Fix a couple of Coverity issues:

1. CID 1175508; file descriptors used in KLockFile could be leaked in
error conditions. Even when KLockFile sets mustCloseFd, the dtor's impl
also checks that the lock has been taken, which is only considered true
if LockOK had been returned in our lock function. Instead close() the fd
ourselves unless we make it to LockOK.

2. CID 1175555; The standard mis-use of QCache. QCache::insert can, in
theory, delete our object as soon as we insert it into cache, so we have
to check for that. Even ::contains() and ::object() can be risky (the
pointers returned by object() have no lifetime guarantee), but since
this is GUI code I assume it's only used single-threaded and not
re-entrant. Otherwise we'd need even more paranoia...

Diffs
-----

  src/kdecore/klockfile_unix.cpp 67283a5 
  src/kdeui/k4style.cpp a1a2ab1 

Diff: https://git.reviewboard.kde.org/r/126507/diff/

Testing
-------

Everything builds and appears to still work, though it's hard to test K4Style as I'm \
not sure what uses it right at this point.

Thanks,

Michael Pyne

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      This is an automatically generated e-mail. To reply, visit:
      <a href="https://git.reviewboard.kde.org/r/126507/">https://git.reviewboard.kde.org/r/126507/</a>
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<div>Review request for KDE Frameworks.</div>
<div>By Michael Pyne.</div>

<div style="margin-top: 1.5em;">
 <b style="color: #575012; font-size: 10pt;">Repository: </b>
kdelibs4support
</div>

<h1 style="color: #575012; font-size: 10pt; margin-top: 1.5em;">Description </h1>
 <table width="100%" bgcolor="#ffffff" cellspacing="0" cellpadding="10" \
style="border: 1px solid #b8b5a0">  <tr>
  <td>
   <pre style="margin: 0; padding: 0; white-space: pre-wrap; white-space: \
-moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: \
break-word;"><p style="padding: 0;text-rendering: inherit;margin: 0;line-height: \
inherit;white-space: inherit;">Fix a couple of Coverity issues:</p> <ol \
style="padding: 0;text-rendering: inherit;margin: 0 0 0 2em;line-height: \
inherit;white-space: normal;"> <li style="padding: 0;text-rendering: inherit;margin: \
0;line-height: inherit;white-space: normal;"> <p style="padding: 0;text-rendering: \
inherit;margin: 0;line-height: inherit;white-space: inherit;">CID 1175508; file \
descriptors used in KLockFile could be leaked in error conditions. Even when \
KLockFile sets mustCloseFd, the dtor's impl also checks that the lock has been taken, \
which is only considered true if LockOK had been returned in our lock function. \
Instead close() the fd ourselves unless we make it to LockOK.</p>
</li>
<li style="padding: 0;text-rendering: inherit;margin: 0;line-height: \
inherit;white-space: normal;"> <p style="padding: 0;text-rendering: inherit;margin: \
0;line-height: inherit;white-space: inherit;">CID 1175555; The standard mis-use of \
QCache. QCache::insert can, in theory, delete our object as soon as we insert it into \
cache, so we have to check for that. Even ::contains() and ::object() can be risky \
(the pointers returned by object() have no lifetime guarantee), but since
this is GUI code I assume it's only used single-threaded and not
re-entrant. Otherwise we'd need even more paranoia...</p>
</li>
</ol></pre>
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</table>

<h1 style="color: #575012; font-size: 10pt; margin-top: 1.5em;">Testing </h1>
<table width="100%" bgcolor="#ffffff" cellspacing="0" cellpadding="10" style="border: \
1px solid #b8b5a0">  <tr>
  <td>
   <pre style="margin: 0; padding: 0; white-space: pre-wrap; white-space: \
-moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: \
break-word;"><p style="padding: 0;text-rendering: inherit;margin: 0;line-height: \
inherit;white-space: inherit;">Everything builds and appears to still work, though \
it's hard to test K4Style as I'm not sure what uses it right at this point.</p></pre> \
</td>  </tr>
</table>

<h1 style="color: #575012; font-size: 10pt; margin-top: 1.5em;">Diffs</b> </h1>
<ul style="margin-left: 3em; padding-left: 0;">

 <li>src/kdecore/klockfile_unix.cpp <span style="color: grey">(67283a5)</span></li>

 <li>src/kdeui/k4style.cpp <span style="color: grey">(a1a2ab1)</span></li>

</ul>

<p><a href="https://git.reviewboard.kde.org/r/126507/diff/" style="margin-left: \
3em;">View Diff</a></p>

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