On 26.01.2016 19:25, Jason J. Herne wrote: > libvirtd crashes on free()ing portData for an open vswitch port if that port > was deleted. To reproduce: > > ovs-vsctl del-port vnet0 > virsh migrate --live kvm1 qemu+ssh://dstHost/system > > Error message: > libvirtd: *** Error in `/usr/sbin/libvirtd': free(): invalid pointer: > 0x000003ff90001e20 *** > > The problem is that virCommandRun can return an empty string in the event that > the port being queried does not exist. When this happens then we are > unconditionally overwriting a newline character at position strlen()-1. When > strlen is 0, we overwrite memory that does not belong to the string. > > The fix: Only overwrite the newline if the string is not empty. > > Reviewed-by: Bjoern Walk <[email protected]> > Signed-off-by: Jason J. Herne <[email protected]> > --- > src/util/virnetdevopenvswitch.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/src/util/virnetdevopenvswitch.c b/src/util/virnetdevopenvswitch.c > index 6780fb5..0f640d0 100644 > --- a/src/util/virnetdevopenvswitch.c > +++ b/src/util/virnetdevopenvswitch.c > @@ -222,8 +222,10 @@ int virNetDevOpenvswitchGetMigrateData(char **migrate, > const char *ifname) > goto cleanup; > } > > - /* Wipeout the newline */ > - (*migrate)[strlen(*migrate) - 1] = '\0'; > + /* Wipeout the newline, if it exists */ > + if (strlen(*migrate) > 0) { > + (*migrate)[strlen(*migrate) - 1] = '\0'; > + }
I'd rather see us computing the length of string once but I guess compiler is wise enough to optimize the code for us. Michal -- libvir-list mailing list [email protected] https://www.redhat.com/mailman/listinfo/libvir-list
