[libvirt] [PATCH v2] qemu: Fix crash hot plugging luks volume
https://bugzilla.redhat.com/show_bug.cgi?id=1367259
Crash occurs because 'secrets' is being dereferenced in call:
if (qemuDomainSecretSetup(conn, priv, secinfo, disk->info.alias,
VIR_SECRET_USAGE_TYPE_VOLUME, NULL,
&src->encryption->secrets[0]->seclookupdef,
true) < 0)
(gdb) p *src->encryption
$1 = {format = 2, nsecrets = 0, secrets = 0x0, encinfo = {cipher_size = 0,
cipher_name = 0x0, cipher_mode = 0x0, cipher_hash = 0x0, ivgen_name = 0x0,
ivgen_hash = 0x0}}
(gdb) bt
priv=priv@entry=0x7fffc03be160, disk=disk@entry=0x7fffb4002ae0)
at qemu/qemu_domain.c:1087
disk=0x7fffb4002ae0, vm=0x7fffc03a2580, driver=0x7fffc02ca390,
conn=0x7fffb00009a0) at qemu/qemu_hotplug.c:355
Upon entry to qemuDomainAttachVirtioDiskDevice, src->encryption points
at a valid 'secret' buffer w/ nsecrets == 1; however, the call to
qemuDomainDetermineDiskChain will call virStorageFileGetMetadata
and eventually virStorageFileGetMetadataInternal where the src->encryption
was overwritten when probing the volume.
Commit id 'a48c7141' added code to virStorageFileGetMetadataInternal
to determine if the disk/volume would use/need encryption and allocated
a meta->encryption. This overwrote an existing encryption buffer
already provided by the XML
This patch adds a check for meta->encryption already present before
just allocating and overwriting an existing buffer. It then checks the
existing encryption data to ensure the XML provided format for the
disk matches the expected format read from the disk and errors if there
is a mismatch.
Signed-off-by: John Ferlan <jferlan(a)redhat.com>
---
v1: http://www.redhat.com/archives/libvir-list/2016-August/msg00805.html
Tested w/ delete luks volume, create luks volume, dump luks volume,
attach to guest, detach from guest, and repeat...
src/util/virstoragefile.c | 19 +++++++++++++++----
1 file changed, 15 insertions(+), 4 deletions(-)
diff --git a/src/util/virstoragefile.c b/src/util/virstoragefile.c
index 471aa1f..feeb061 100644
--- a/src/util/virstoragefile.c
+++ b/src/util/virstoragefile.c
@@ -950,10 +950,21 @@ virStorageFileGetMetadataInternal(virStorageSourcePtr meta,
for (i = 0; fileTypeInfo[meta->format].cryptInfo[i].format != 0; i++) {
if
(virStorageFileHasEncryptionFormat(&fileTypeInfo[meta->format].cryptInfo[i],
buf, len)) {
- if (VIR_ALLOC(meta->encryption) < 0)
- goto cleanup;
-
- meta->encryption->format =
fileTypeInfo[meta->format].cryptInfo[i].format;
+ int expt_fmt = fileTypeInfo[meta->format].cryptInfo[i].format;
+ if (!meta->encryption) {
+ if (VIR_ALLOC(meta->encryption) < 0)
+ goto cleanup;
+
+ meta->encryption->format = expt_fmt;
+ } else {
+ if (meta->encryption->format != expt_fmt) {
+ virReportError(VIR_ERR_XML_ERROR,
+ _("encryption format %d doesn't match
"
+ "expected format %d"),
+ meta->encryption->format, expt_fmt);
+ goto cleanup;
+ }
+ }
}
}
}
--
2.7.4