Re: [libvirt] [PATCH] fix crash when starting network

On 11/02/2011 01:17 AM, Wen Congyang wrote: > commit 27908453 introduces a regression, and it will > cause libvirt crashed when starting network. > > The reason is that tapfd may be NULL, but we dereference > it without checking whether it is NULL. > > --- > src/util/bridge.c | 18 ++++++++++-------- > 1 files changed, 10 insertions(+), 8 deletions(-) > > diff --git a/src/util/bridge.c b/src/util/bridge.c > index 952f0f3..6774f99 100644 > --- a/src/util/bridge.c > +++ b/src/util/bridge.c > @@ -484,7 +484,8 @@ brAddTap(brControl *ctl, > > errno = brCreateTap(ctl, ifname, vnet_hdr, tapfd); > > - if (*tapfd< 0 || errno) > + /* fd has been closed in brCreateTap() when it failed. */ > + if (errno) > goto error; > > /* We need to set the interface MAC before adding it > @@ -494,22 +495,23 @@ brAddTap(brControl *ctl, > * device before we set our static MAC. > */ > if ((errno = brSetInterfaceMac(ctl, *ifname, macaddr))) > - goto error; > + goto close_fd; > /* We need to set the interface MTU before adding it > * to the bridge, because the bridge will have its > * MTU adjusted automatically when we add the new interface. > */ > if ((errno = brSetInterfaceMtu(ctl, bridge, *ifname))) > - goto error; > + goto close_fd; > if ((errno = brAddInterface(ctl, bridge, *ifname))) > - goto error; > + goto close_fd; > if (up&& ((errno = brSetInterfaceUp(ctl, *ifname, 1)))) > - goto error; > + goto close_fd; > return 0; > > - error: > - VIR_FORCE_CLOSE(*tapfd); > - > +close_fd: > + if (tapfd) > + VIR_FORCE_CLOSE(*tapfd); It's not necessary to test for tapfd. This is similar to VIR_FREE(). Besides that you should test for if(tapfd>=0) if testing at all.

Stefan > +error: > return errno; > } > -- libvir-list mailing list libvir-list(a)redhat.com https://www.redhat.com/mailman/listinfo/libvir-list