On Fri, 4 Oct 2019 at 17:42, Julien Grall <[email protected]> wrote: > > flask_assign_{, dt}device() may be used to check whether you can test if > a device is assigned. In this case, the domain will be NULL. > > However, flask_iommu_resource_use_perm() will be called and may end up > to deference a NULL pointer. This can be prevented by moving the call > after we check the validity for the domain pointer. > > Coverity-ID: 1486741 > Fixes: 71e617a6b8 ('use is_iommu_enabled() where appropriate...') > Signed-off-by: Julien Grall <[email protected]>
Reviewed-by: Paul Durrant <[email protected]> > --- > xen/xsm/flask/hooks.c | 8 ++++++-- > 1 file changed, 6 insertions(+), 2 deletions(-) > > diff --git a/xen/xsm/flask/hooks.c b/xen/xsm/flask/hooks.c > index 3b30827764..cf7f25cda2 100644 > --- a/xen/xsm/flask/hooks.c > +++ b/xen/xsm/flask/hooks.c > @@ -1296,11 +1296,13 @@ static int flask_assign_device(struct domain *d, > uint32_t machine_bdf) > u32 dsid, rsid; > int rc = -EPERM; > struct avc_audit_data ad; > - u32 dperm = flask_iommu_resource_use_perm(d); > + u32 dperm; > > if ( !d ) > return flask_test_assign_device(machine_bdf); > > + dperm = flask_iommu_resource_use_perm(d); > + > rc = current_has_perm(d, SECCLASS_RESOURCE, RESOURCE__ADD); > if ( rc ) > return rc; > @@ -1355,11 +1357,13 @@ static int flask_assign_dtdevice(struct domain *d, > const char *dtpath) > u32 dsid, rsid; > int rc = -EPERM; > struct avc_audit_data ad; > - u32 dperm = flask_iommu_resource_use_perm(d); > + u32 dperm; > > if ( !d ) > return flask_test_assign_dtdevice(dtpath); > > + dperm = flask_iommu_resource_use_perm(d); > + > rc = current_has_perm(d, SECCLASS_RESOURCE, RESOURCE__ADD); > if ( rc ) > return rc; > -- > 2.11.0 > _______________________________________________ Xen-devel mailing list [email protected] https://lists.xenproject.org/mailman/listinfo/xen-devel
