Re: [libvirt] [PATCH] virsh: avoid uninitialized memory usage

On 04/19/2012 04:19 PM, Wen Congyang wrote: > At 04/19/2012 04:09 PM, Alex Jia Wrote: >> Detected by valgrind. >> >> * tools/virsh.c (cmdBlockPull): fix uninitialized memory usage. >> >> * How to reproduce? >> $ qemu-img create /var/lib/libvirt/images/test 1M >> $ cat> /tmp/test.xml<<EOF >> <domain type='qemu'> >> <name>test</name> >> <memory>219200</memory> >> <vcpu>1</vcpu> >> <os> >> <type arch='x86_64'>hvm</type> >> <boot dev='hd'/> >> </os> >> <devices> >> <disk type='file' device='disk'> >> <driver name='qemu' type='raw'/> >> <source file='/var/lib/libvirt/images/test'/> >> <target dev='vda' bus='virtio'/> >> </disk> >> <input type='mouse' bus='ps2'/> >> <graphics type='spice' autoport='yes' listen='0.0.0.0'/> >> </devices> >> </domain> >> EOF >> $ virsh define /tmp/test.xml >> $ valgrind -v virsh blockpull test /var/lib/libvirt/images/test --wait >> >> actual result: >> >> ==10906== 1 errors in context 1 of 1: >> ==10906== Syscall param rt_sigaction(act->sa_flags) points to >> uninitialised byte(s) >> ==10906== at 0x39CF80F5BE: __libc_sigaction (sigaction.c:67) >> ==10906== by 0x43016C: cmdBlockPull (virsh.c:7638) >> ==10906== by 0x4150D4: vshCommandRun (virsh.c:18574) >> ==10906== by 0x425E73: main (virsh.c:20178) >> ==10906== Address 0x7fefffae8 is on thread 1's stack >> >> >> Signed-off-by: Alex Jia&lt;ajia(a)redhat.com&gt; >> --- >> tools/virsh.c | 1 + >> 1 files changed, 1 insertions(+), 0 deletions(-) >> >> diff --git a/tools/virsh.c b/tools/virsh.c >> index 95ed7bc..4e4ca57 100644 >> --- a/tools/virsh.c >> +++ b/tools/virsh.c >> @@ -7634,6 +7634,7 @@ cmdBlockPull(vshControl *ctl, const vshCmd *cmd) >> >> intCaught = 0; >> sig_action.sa_sigaction = vshCatchInt; >> + sigemptyset((sigset_t *)&sig_action.sa_flags); > Why using sigemptyset here? You should use 'sig_action.sa_flags = 0'. Yeah, I think 'sig_action.sa_flags = 0' is right, but I don't know what the difference are, could you explain more?

Thanks, Alex > Thanks > Wen Congyang > >> sigemptyset(&sig_action.sa_mask); >> sigaction(SIGINT,&sig_action,&old_sig_action); >> -- libvir-list mailing list libvir-list(a)redhat.com https://www.redhat.com/mailman/listinfo/libvir-list