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 <julien.grall@arm.com>
---
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
Xen-devel@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-devel
On Fri, 4 Oct 2019 at 17:42, Julien Grall <julien.grall@arm.com> 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 <julien.grall@arm.com> Reviewed-by: Paul Durrant <paul@xen.org> > --- > 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 Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel
On 04.10.19 18:42, Julien Grall 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 <julien.grall@arm.com> Release-acked-by: Juergen Gross <jgross@suse.com> Juergen _______________________________________________ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel
© 2016 - 2024 Red Hat, Inc.