[libvirt] [PATCH] Fix crash in DAC driver with no seclabels

[Laine Stump]

On 05/19/2014 02:59 PM, Ján Tomko wrote:
> With dynamic_ownership = 1 but no seclabels, RestoreChardevLabel
> dereferences the NULL seclabel when checking if norelabel is set.


Uh, ACK :-) (Since this patch allows a newly rebuilt libvirtd to once
again startup without an immediate crash)

>
> Remove this check, since it is already done in RestoreSecurityAllLabel
> and if norelabel is set, RestoreChardevLabel is never called.
> ---
>  src/security/security_dac.c | 7 ++-----
>  1 file changed, 2 insertions(+), 5 deletions(-)
>
> diff --git a/src/security/security_dac.c b/src/security/security_dac.c
> index 05303e7..00f47cb 100644
> --- a/src/security/security_dac.c
> +++ b/src/security/security_dac.c
> @@ -768,22 +768,19 @@ virSecurityDACSetChardevLabel(virSecurityManagerPtr mgr,
>  
>  static int
>  virSecurityDACRestoreChardevLabel(virSecurityManagerPtr mgr ATTRIBUTE_UNUSED,
> -                                  virDomainDefPtr def,
> +                                  virDomainDefPtr def ATTRIBUTE_UNUSED,
>                                    virDomainChrDefPtr dev,
>                                    virDomainChrSourceDefPtr dev_source)
>  {
> -    virSecurityLabelDefPtr seclabel;
>      virSecurityDeviceLabelDefPtr chr_seclabel = NULL;
>      char *in = NULL, *out = NULL;
>      int ret = -1;
>  
> -    seclabel = virDomainDefGetSecurityLabelDef(def, SECURITY_DAC_NAME);
> -
>      if (dev)
>          chr_seclabel = virDomainChrDefGetSecurityLabelDef(dev,
>                                                            SECURITY_DAC_NAME);
>  
> -    if (seclabel->norelabel || (chr_seclabel && chr_seclabel->norelabel))
> +    if (chr_seclabel && chr_seclabel->norelabel)
>          return 0;
>  
>      switch ((enum virDomainChrType) dev_source->type) {