vircgroupv2devices: Avoid double close on map FD

When allowing/denying a device in devices CGroupV2 we have to
write a BPF program for it. The program we put there is merely
static and all it does it looks up a device in a hash table (also
known as map in BPF terminology). A map is referenced via an FD
which can be acquired via virBPFCreateMap() and like any other FD
it should be closed when no longer needed. However, we close it
twice: the first time in virCgroupV2DevicesAttachProg() which
closes it unconditionally, and the second time in either
virCgroupV2DevicesCreateProg() or
virCgroupV2DevicesPrepareProg(). Remove the second close.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
This commit is contained in:
Michal Privoznik 2020-01-06 15:06:20 +01:00
parent ff878fe77c
commit 529100d9f7

View File

@ -494,7 +494,7 @@ virCgroupV2DevicesReallocMap(int mapfd,
int
virCgroupV2DevicesCreateProg(virCgroupPtr group)
{
VIR_AUTOCLOSE mapfd = -1;
int mapfd = -1;
if (group->unified.devices.progfd > 0 && group->unified.devices.mapfd > 0)
return 0;
@ -503,13 +503,8 @@ virCgroupV2DevicesCreateProg(virCgroupPtr group)
if (mapfd < 0)
return -1;
if (virCgroupV2DevicesAttachProg(group, mapfd,
VIR_CGROUP_V2_INITIAL_BPF_MAP_SIZE) < 0) {
return -1;
}
mapfd = -1;
return 0;
return virCgroupV2DevicesAttachProg(group, mapfd,
VIR_CGROUP_V2_INITIAL_BPF_MAP_SIZE);
}
@ -530,10 +525,8 @@ virCgroupV2DevicesPrepareProg(virCgroupPtr group)
if (newmapfd < 0)
return -1;
if (virCgroupV2DevicesAttachProg(group, newmapfd, max) < 0) {
VIR_FORCE_CLOSE(newmapfd);
if (virCgroupV2DevicesAttachProg(group, newmapfd, max) < 0)
return -1;
}
}
return 0;