JDK-8260432: allocateSpaceForGP in freetypeScaler.c might leak memory #2250

MBaesken · 2021-01-27T08:39:33Z

The function AllocateSpaceForGP in freetypeScaler.c calls potentially 2 times malloc ; however the memory is not always freed correctly in case of errors.
See also the related sonar issue :
https://sonarcloud.io/project/issues?id=shipilev_jdk&languages=c&open=AXck8B_SBBG2CXpcngxr&resolved=false&severities=BLOCKER&types=BUG

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Issue

JDK-8260432: allocateSpaceForGP in freetypeScaler.c might leak memory

Reviewers

Aleksey Shipilev (@shipilev - Reviewer) ⚠️ Review applies to afda19e
Thomas Stuefe (@tstuefe - Reviewer)

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$ git fetch https://git.openjdk.java.net/jdk pull/2250/head:pull/2250
$ git checkout pull/2250

bridgekeeper · 2021-01-27T08:40:28Z

👋 Welcome back mbaesken! A progress list of the required criteria for merging this PR into master will be added to the body of your pull request. There are additional pull request commands available for use with this pull request.

openjdk · 2021-01-27T08:41:32Z

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mlbridge · 2021-01-27T08:44:53Z

Webrevs

shipilev · 2021-01-27T11:41:48Z

src/java.desktop/share/native/libfontmanager/freetypeScaler.c

@@ -1285,7 +1287,7 @@ static int allocateSpaceForGP(GPData* gpdata, int npoints, int ncontours) {
    }

    /* failure if any of mallocs failed */
-    if (gpdata->pointTypes == NULL ||  gpdata->pointCoords == NULL)
+    if (gpdata->pointTypes == NULL || gpdata->pointCoords == NULL)


I think it would be cleaner to free the remaining allocations on the failing path:

if (gpdata->pointTypes == NULL || gpdata->pointCoords == NULL) { if (gpdata->pointTypes != NULL) free(gpdata->pointTypes); if (gpdata->pointCoords != NULL) free(gpdata->pointCoords); return 0; } else { return 1; }

Then we would free as well for the realloc code path
} else {
/* do we have enough space? */
...
}
Is this okay?

Yes, I think that is better: realloc can fail as well, and we don't want to leak those?

Please also reset the free'd pointers to NULL in GPData* before returning.

Hello Thomas and Aleksey, I moved the free calls and added the NULL settings. Are you fine with the latest commit?
Thanks, Matthias

shipilev

This looks fine to me, modulo stylistic nits

shipilev · 2021-01-28T07:51:59Z

src/java.desktop/share/native/libfontmanager/freetypeScaler.c

@@ -1285,10 +1285,12 @@ static int allocateSpaceForGP(GPData* gpdata, int npoints, int ncontours) {
    }

    /* failure if any of mallocs failed */
-    if (gpdata->pointTypes == NULL ||  gpdata->pointCoords == NULL)
+    if (gpdata->pointTypes == NULL || gpdata->pointCoords == NULL) {
+        if (gpdata->pointTypes != NULL)  { free(gpdata->pointTypes); gpdata->pointTypes = NULL; }


You might want to add an extra space before gpdata->pointTypes = NULL; to align the statements vertically. You call.

Can we also style it consistently, like:

if (gpdata->pointTypes != NULL) { free(gpdata->pointTypes); gpdata->pointTypes = NULL; } if (gpdata->pointCoords != NULL) { free(gpdata->pointCoords); gpdata->pointCoords = NULL; }

shipilev · 2021-01-28T07:54:21Z

Pull from master to get x86_32 GHA jobs fixed and running.

openjdk · 2021-01-28T07:54:25Z

@MBaesken This change now passes all automated pre-integration checks.

ℹ️ This project also has non-automated pre-integration requirements. Please see the file CONTRIBUTING.md for details.

After integration, the commit message for the final commit will be:

8260432: allocateSpaceForGP in freetypeScaler.c might leak memory

Reviewed-by: shade, stuefe

You can use pull request commands such as /summary, /contributor and /issue to adjust it as needed.

At the time when this comment was updated there had been 23 new commits pushed to the master branch:

11a70d1: 8260426: awt debug_mem.c DMem_AllocateBlock might leak memory
396a496: 8260467: Move well-known classes from systemDictionary.hpp to vmClasses.hpp
62ffe75: Merge
e28e111: 8260370: C2: LoopLimit node is not eliminated
7030d2e: 8260200: G1: Remove unnecessary update in FreeRegionList::remove_starting_at
c7661ae: 8260561: [doc] HexFormat has incorrect @SInCE tag
c52212b: Merge
408772c: 8259025: Record compact constructor using Objects.requireNonNull
81e730e: 8259276: C2: Empty expression stack when reexecuting tableswitch/lookupswitch instructions after deoptimization
c5ab7c3: 8260284: C2: assert(_base == Int) failed: Not an Int
... and 13 more: https://git.openjdk.java.net/jdk/compare/fd2641ed36c8cdb59c33675bd9ed909b47cd002e...master

As there are no conflicts, your changes will automatically be rebased on top of these commits when integrating. If you prefer to avoid this automatic rebasing, please check the documentation for the /integrate command for further details.

➡️ To integrate this PR with the above commit message to the master branch, type /integrate in a new comment.

tstuefe

Hi Matthias,

looks fine. See remark below, but that is just nitpicking, this is fine as it is.

Cheers, Thomas

tstuefe · 2021-01-28T09:11:09Z

src/java.desktop/share/native/libfontmanager/freetypeScaler.c

+        if (gpdata->pointCoords != NULL) {
+            free(gpdata->pointCoords);
+            gpdata->pointCoords = NULL;
+        }
        return 0;


If you wanted, you could streamline this to:

if (gpdata->pointTypes == NULL || gpdata->pointCoords == NULL) { free(gpdata->pointTypes); free(gpdata->pointCoords); gpdata->pointTypes = gpdata->pointCoords = NULL; return 0;

Since free(NULL) is valid and a noop.

MBaesken · 2021-01-28T15:20:15Z

/integrate

openjdk · 2021-01-28T15:21:24Z

@MBaesken Since your change was applied there have been 35 commits pushed to the master branch:

abc4300: 8257746: Regression introduced with JDK-8250984 - memory might be null in some machines
13ca433: 8259628: jdk/net/ExtendedSocketOption/AsynchronousSocketChannelNAPITest.java fails intermittently
baf46ba: 8259801: Enable XML Signature secure validation mode by default
20e7df5: 8260466: Test TestHeapDumpOnOutOfMemoryError.java needs multiple @test sections
11d6467: 8260407: cmp != __null && cmp->Opcode() == Op_CmpL failure with -XX:StressLongCountedLoop=200000000 in lucene
d07af2b: 8255531: MethodHandles::permuteArguments throws NPE when duplicating dropped arguments
a68c6c2: 8260579: PPC64 and S390 builds failures after JDK-8260467
8752257: 8260502: [s390] NativeMovRegMem::verify() fails because it's too strict
8fe1323: 8260520: Avoid getting permissions in JarFileFactory when no SecurityManager installed
ecde52e: 8260506: VersionHelper cleanup
... and 25 more: https://git.openjdk.java.net/jdk/compare/fd2641ed36c8cdb59c33675bd9ed909b47cd002e...master

Your commit was automatically rebased without conflicts.

Pushed as commit 3aabbd7.

💡 You may see a message that your pull request was closed with unmerged commits. This can be safely ignored.

JDK-8260432

5c86722

openjdk bot added the rfr Pull request is ready for review label Jan 27, 2021

openjdk bot added the 2d client-libs-dev@openjdk.org label Jan 27, 2021

shipilev suggested changes Jan 27, 2021

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JDK-8260426

afda19e

shipilev approved these changes Jan 28, 2021

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openjdk bot added the ready Pull request is ready to be integrated label Jan 28, 2021

JDK-8260426

70c3e87

tstuefe approved these changes Jan 28, 2021

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openjdk bot closed this Jan 28, 2021

openjdk bot added integrated Pull request has been integrated and removed ready Pull request is ready to be integrated rfr Pull request is ready for review labels Jan 28, 2021

JDK-8260432: allocateSpaceForGP in freetypeScaler.c might leak memory #2250

JDK-8260432: allocateSpaceForGP in freetypeScaler.c might leak memory #2250

MBaesken commented Jan 27, 2021 •

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openjdk bot commented Jan 28, 2021

JDK-8260432: allocateSpaceForGP in freetypeScaler.c might leak memory #2250

JDK-8260432: allocateSpaceForGP in freetypeScaler.c might leak memory #2250

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MBaesken commented Jan 27, 2021 • edited by openjdk bot

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