Re: [libvirt] [PATCH 1/2] blockjob: avoid memory leak during block pivot

Valgrind caught a memory leak: ==2018== 9 bytes in 1 blocks are definitely lost in loss record 143 of 927 ==2018== at 0x4A0645D: malloc (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so) ==2018== by 0x8C42369: strdup (strdup.c:42) ==2018== by 0x50EACC9: virStrdup (virstring.c:676) ==2018== by 0x50E79E5: virStorageSourceCopy (virstoragefile.c:1845) ==2018== by 0x20A3FAA7: qemuDomainBlockCommit (qemu_driver.c:15620) ==2018== by 0x51DC6B2: virDomainBlockCommit (libvirt.c:20092) I traced it to the fact that blockcopy and blockcommit end up reparsing a backing chain on pivot, but the chain parsing code doesn't gracefully handle the case where the backing file is already known. I'm not exactly sure when this was introduced, but suspect that the refactoring in commit 9944b71 and friends that moved towards probing in-place rather than into a temporary structure are part of the cause. * src/util/virstoragefile.c (virStorageFileGetMetadataInternal): Don't leak any prior value. Signed-off-by: Eric Blake <eblake(a)redhat.com&gt; --- src/util/virstoragefile.c | 1 + 1 file changed, 1 insertion(+) diff --git a/src/util/virstoragefile.c b/src/util/virstoragefile.c index 3da9073..5b6b2f5 100644 --- a/src/util/virstoragefile.c +++ b/src/util/virstoragefile.c @@ -817,6 +817,7 @@ virStorageFileGetMetadataInternal(virStorageSourcePtr meta, goto cleanup; } + VIR_FREE(meta->backingStoreRaw); if (fileTypeInfo[meta->format].getBackingStore != NULL) { int store = fileTypeInfo[meta->format].getBackingStore(&meta->backingStoreRaw, backingFormat,