It's easy to shed the daemon these days. With this XML snippet: <disk type='file' device='disk'> <driver name='qemu' type='raw'/> <source file='/some/dummy/path/test.bin'> <seclabel model='dac' relabel='no'/> </source> <target dev='vdb' bus='virtio'/> <readonly/> <address type='pci' domain='0x0000' bus='0x00' slot='0x07' function='0x0'/> </disk> I get the SIGSEGV when starting the domain. The thing is, when starting a domain, we check for its disk presence. For some reason, when determining the disk chain, we parse the <seclabel/> (don't ask me why). However, there's no label attribute in the XML, so we end up calling virParseOwnershipIds() over NULL string: [Switching to Thread 0x7ffff10c4700 (LWP 30956)] __strchr_sse42 () at ../sysdeps/x86_64/multiarch/strchr.S:136 136 ../sysdeps/x86_64/multiarch/strchr.S: No such file or directory. (gdb) bt #0 __strchr_sse42 () at ../sysdeps/x86_64/multiarch/strchr.S:136 #1 0x00007ffff749f800 in virParseOwnershipIds (label=0x0, uidPtr=uidPtr@entry=0x7ffff10c2df0, gidPtr=gidPtr@entry=0x7ffff10c2df4) at util/virutil.c:2115 #2 0x00007fffe929f006 in qemuDomainGetImageIds (gid=0x7ffff10c2df4, uid=0x7ffff10c2df0, disk=0x7fffe40cb000, vm=0x7fffe40a6410, cfg=0x7fffe409ae00) at qemu/qemu_domain.c:2385 #3 qemuDomainDetermineDiskChain (driver=driver@entry=0x7fffe40120e0, vm=vm@entry=0x7fffe40a6410, disk=disk@entry=0x7fffe40cb000, force=force@entry=false) at qemu/qemu_domain.c:2414 #4 0x00007fffe929f128 in qemuDomainCheckDiskPresence (driver=driver@entry=0x7fffe40120e0, vm=vm@entry=0x7fffe40a6410, cold_boot=cold_boot@entry=true) at qemu/qemu_domain.c:2250 #5 0x00007fffe92b6fc8 in qemuProcessStart (conn=conn@entry=0x7fffd4000b60, driver=driver@entry=0x7fffe40120e0, vm=vm@entry=0x7fffe40a6410, migrateFrom=migrateFrom@entry=0x0, stdin_fd=stdin_fd@entry=-1, stdin_path=stdin_path@entry=0x0, snapshot=snapshot@entry=0x0, vmop=vmop@entry=VIR_NETDEV_VPORT_PROFILE_OP_CREATE, flags=flags@entry=1) at qemu/qemu_process.c:3813 #6 0x00007fffe93087e8 in qemuDomainObjStart (conn=0x7fffd4000b60, driver=driver@entry=0x7fffe40120e0, vm=vm@entry=0x7fffe40a6410, flags=flags@entry=0) at qemu/qemu_driver.c:6051 #7 0x00007fffe9308e32 in qemuDomainCreateWithFlags (dom=0x7fffcc000d50, flags=0) at qemu/qemu_driver.c:6105 #8 0x00007ffff753c5cc in virDomainCreate (domain=domain@entry=0x7fffcc000d50) at libvirt.c:8861 Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com&gt; --- src/qemu/qemu_domain.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c index 7d375e5..c76b872 100644 --- a/src/qemu/qemu_domain.c +++ b/src/qemu/qemu_domain.c @@ -2381,7 +2381,8 @@ qemuDomainGetImageIds(virQEMUDriverConfigPtr cfg, if (vm && (vmlabel = virDomainDefGetSecurityLabelDef(vm->def, "dac"))) virParseOwnershipIds(vmlabel->label, uid, gid); - if ((disklabel = virDomainDiskDefGetSecurityLabelDef(disk, "dac"))) + if ((disklabel = virDomainDiskDefGetSecurityLabelDef(disk, "dac")) && + disklabel->label) virParseOwnershipIds(disklabel->label, uid, gid); } -- 1.9.0