diff options
author | Tom Lane | 2014-11-27 16:12:44 +0000 |
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committer | Tom Lane | 2014-11-27 16:13:29 +0000 |
commit | c168ba311228c523923f7ef7699cba96deedcc6d (patch) | |
tree | 35108f646a91dbc33679058aab8a16eeb90da63b | |
parent | 143b39c1855f8a22f474f20354ee5ee5d2f4d266 (diff) |
Free libxml2/libxslt resources in a safer order.
Mark Simonetti reported that libxslt sometimes crashes for him, and that
swapping xslt_process's object-freeing calls around to do them in reverse
order of creation seemed to fix it. I've not reproduced the crash, but
valgrind clearly shows a reference to already-freed memory, which is
consistent with the idea that shutdown of the xsltTransformContext is
trying to reference the already-freed stylesheet or input document.
With this patch, valgrind is no longer unhappy.
I have an inquiry in to see if this is a libxslt bug or if we're just
abusing the library; but even if it's a library bug, we'd want to adjust
our code so it doesn't fail with unpatched libraries.
Back-patch to all supported branches, because we've been doing this in
the wrong(?) order for a long time.
-rw-r--r-- | contrib/xml2/xslt_proc.c | 18 |
1 files changed, 9 insertions, 9 deletions
diff --git a/contrib/xml2/xslt_proc.c b/contrib/xml2/xslt_proc.c index 9f137873322..343924e9917 100644 --- a/contrib/xml2/xslt_proc.c +++ b/contrib/xml2/xslt_proc.c @@ -146,16 +146,16 @@ xslt_process(PG_FUNCTION_ARGS) } PG_CATCH(); { - if (stylesheet != NULL) - xsltFreeStylesheet(stylesheet); if (restree != NULL) xmlFreeDoc(restree); - if (doctree != NULL) - xmlFreeDoc(doctree); - if (xslt_sec_prefs != NULL) - xsltFreeSecurityPrefs(xslt_sec_prefs); if (xslt_ctxt != NULL) xsltFreeTransformContext(xslt_ctxt); + if (xslt_sec_prefs != NULL) + xsltFreeSecurityPrefs(xslt_sec_prefs); + if (stylesheet != NULL) + xsltFreeStylesheet(stylesheet); + if (doctree != NULL) + xmlFreeDoc(doctree); xsltCleanupGlobals(); pg_xml_done(xmlerrcxt, true); @@ -164,11 +164,11 @@ xslt_process(PG_FUNCTION_ARGS) } PG_END_TRY(); - xsltFreeStylesheet(stylesheet); xmlFreeDoc(restree); - xmlFreeDoc(doctree); - xsltFreeSecurityPrefs(xslt_sec_prefs); xsltFreeTransformContext(xslt_ctxt); + xsltFreeSecurityPrefs(xslt_sec_prefs); + xsltFreeStylesheet(stylesheet); + xmlFreeDoc(doctree); xsltCleanupGlobals(); pg_xml_done(xmlerrcxt, false); |