Re: [libvirt] [PATCH] conf: initialize character pointer xml value to avoid random crash

If the code jump to the cleanup before assagin value to xml pointer, libvirtd may get crashed when try to free an uninitialized pointer. backtrace: 0 0x00007ffff428d59c in free () from /lib64/libc.so.6 1 0x00007ffff721314a in virFree (ptrptr=ptrptr@entry=0x7fffc67f1b00) at util/viralloc.c:582 2 0x00007ffff7345ac4 in virDomainConfNWFilterInstantiate (vmname=<optimized out>, vmuuid=vmuuid@entry=0x7fffc0181ca8 "߉\237\\۔H\262\206z\340\302f\265\233z", net=<optimized out>, ignoreExists=ignoreExists@entry=true) at conf/domain_nwfilter.c:122 3 0x00007fffca5a77f6 in qemuProcessFiltersInstantiate (ignoreExists=true, def=0x7fffc0181ca0) at qemu/qemu_process.c:3028 4 qemuProcessReconnect (opaque=<optimized out>) at qemu/qemu_process.c:7653 5 0x00007ffff72c4895 in virThreadHelper (data=<optimized out>) at util/virthread.c:206 6 0x00007ffff45dcdd5 in start_thread () from /lib64/libpthread.so.0 7 0x00007ffff4305ead in clone () from /lib64/libc.so.6 Signed-off-by: Luyao Huang <lhuang(a)redhat.com&gt; --- src/conf/domain_nwfilter.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/src/conf/domain_nwfilter.c b/src/conf/domain_nwfilter.c index 948b324..24b5f42 100644 --- a/src/conf/domain_nwfilter.c +++ b/src/conf/domain_nwfilter.c @@ -90,7 +90,7 @@ virDomainConfNWFilterInstantiate(const char *vmname, virConnectPtr conn = virGetConnectNWFilter(); virNWFilterBindingDefPtr def = NULL; virNWFilterBindingPtr binding = NULL; - char *xml; + char *xml = NULL; int ret = -1; VIR_DEBUG("vmname=%s portdev=%s filter=%s ignoreExists=%d",