Re: [libvirt] [PATCH 1/2] qemu: blockPeek: Fix filling of the return buffer

On 09/18/2017 09:11 AM, Peter Krempa wrote: > Commit 3956af495e broke the blockPeek API since virStorageFileRead > allocates a return buffer and fills it with the data, while the API > fills a user-provided buffer. This did not get caught by the compiler > since the API prototype uses a 'void *'. > > Fix it by transferring the data from the allocated buffer to the user > provided buffer. > > Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1491217 > --- > src/qemu/qemu_driver.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c > index e1a0dd553..93a1c6061 100644 > --- a/src/qemu/qemu_driver.c > +++ b/src/qemu/qemu_driver.c > @@ -11415,6 +11415,7 @@ qemuDomainBlockPeek(virDomainPtr dom, > virQEMUDriverPtr driver = dom->conn->privateData; > virDomainDiskDefPtr disk = NULL; > virDomainObjPtr vm; > + char *tmpbuf = NULL; > int ret = -1; > > virCheckFlags(0, -1); > @@ -11444,12 +11445,15 @@ qemuDomainBlockPeek(virDomainPtr dom, > if (virStorageFileRead(disk->src, offset, size, buffer) < 0) > goto cleanup; > > + memcpy(buffer, tmpbuf, size); Umm, where is tmpbuf actually set to a non-null pointer? Shouldn't the virStorageFileRead() call also be updated?