[libvirt] [PATCH] security: apparmor: Label externalDataStore
Teach virt-aa-helper how to label a qcow2 data_file, tracked internally as externalDataStore. It should be treated the same as its sibling disk image Signed-off-by: Cole Robinson <crobinso@redhat.com> --- Compiled but not runtime tested, I don't have an apparmor setup src/security/virt-aa-helper.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/src/security/virt-aa-helper.c b/src/security/virt-aa-helper.c index 509187ac36..fe6fa12550 100644 --- a/src/security/virt-aa-helper.c +++ b/src/security/virt-aa-helper.c @@ -949,6 +949,10 @@ storage_source_add_files(virStorageSourcePtr src, if (add_file_path(tmp, depth, buf) < 0) return -1; + if (src->externalDataStore && + storage_source_add_files(src->externalDataStore, buf, depth) < 0) + return -1; + depth++; } -- 2.23.0
ping On 10/11/19 3:14 PM, Cole Robinson wrote:
Teach virt-aa-helper how to label a qcow2 data_file, tracked internally as externalDataStore. It should be treated the same as its sibling disk image
Signed-off-by: Cole Robinson <crobinso@redhat.com> --- Compiled but not runtime tested, I don't have an apparmor setup
src/security/virt-aa-helper.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/src/security/virt-aa-helper.c b/src/security/virt-aa-helper.c index 509187ac36..fe6fa12550 100644 --- a/src/security/virt-aa-helper.c +++ b/src/security/virt-aa-helper.c @@ -949,6 +949,10 @@ storage_source_add_files(virStorageSourcePtr src, if (add_file_path(tmp, depth, buf) < 0) return -1;
+ if (src->externalDataStore && + storage_source_add_files(src->externalDataStore, buf, depth) < 0) + return -1; + depth++; }
On Fri, Oct 11, 2019 at 9:13 PM Cole Robinson <crobinso@redhat.com> wrote:
Teach virt-aa-helper how to label a qcow2 data_file, tracked internally as externalDataStore. It should be treated the same as its sibling disk image
Signed-off-by: Cole Robinson <crobinso@redhat.com> --- Compiled but not runtime tested, I don't have an apparmor setup
src/security/virt-aa-helper.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/src/security/virt-aa-helper.c b/src/security/virt-aa-helper.c index 509187ac36..fe6fa12550 100644 --- a/src/security/virt-aa-helper.c +++ b/src/security/virt-aa-helper.c @@ -949,6 +949,10 @@ storage_source_add_files(virStorageSourcePtr src, if (add_file_path(tmp, depth, buf) < 0) return -1;
+ if (src->externalDataStore && + storage_source_add_files(src->externalDataStore, buf, depth)
< 0)
+ return -1; +
After thinking twice about it ack to carry over depth as only the first layer should only ever need write permissions on those extra files as well. But I'm unsure about using "src->externalDataStore". After all this does initialize "tmp = src". And then iterates the (potential) backing chain. That way each loop iteration has a different "tmp" along the backing chain but "src" will always point to the first entry. It comes down to a detail question about the design of external data in qcow. In a case with a base file and two snapshots, does the chain look like: A: Current -> Snap2 -> Snap1 \ external data or B: Current -> Snap2 -> Snap1 \ \ \ ext-dat2 ext-dat1 ext-dat or C: Current -> Snap2 -> Snap1 \ external data Depending on that it should IMHO be a) call storage_source_add_files outside the loop and with depth arg always set to zero b+c) call storage_source_add_files with tmp instead of src as argument (also use tmp in the check if externalDataStore exists)
depth++; }
-- 2.23.0
-- Christian Ehrhardt Staff Engineer, Ubuntu Server Canonical Ltd
On Mon, Dec 09, 2019 at 07:50:09 +0100, Christian Ehrhardt wrote:
On Fri, Oct 11, 2019 at 9:13 PM Cole Robinson <crobinso@redhat.com> wrote:
Teach virt-aa-helper how to label a qcow2 data_file, tracked internally as externalDataStore. It should be treated the same as its sibling disk image
Signed-off-by: Cole Robinson <crobinso@redhat.com> --- Compiled but not runtime tested, I don't have an apparmor setup
src/security/virt-aa-helper.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/src/security/virt-aa-helper.c b/src/security/virt-aa-helper.c index 509187ac36..fe6fa12550 100644 --- a/src/security/virt-aa-helper.c +++ b/src/security/virt-aa-helper.c @@ -949,6 +949,10 @@ storage_source_add_files(virStorageSourcePtr src, if (add_file_path(tmp, depth, buf) < 0) return -1;
+ if (src->externalDataStore && + storage_source_add_files(src->externalDataStore, buf, depth)
< 0)
+ return -1; +
After thinking twice about it ack to carry over depth as only the first layer should only ever need write permissions on those extra files as well.
But I'm unsure about using "src->externalDataStore". After all this does initialize "tmp = src". And then iterates the (potential) backing chain. That way each loop iteration has a different "tmp" along the backing chain but "src" will always point to the first entry.
It comes down to a detail question about the design of external data in qcow. In a case with a base file and two snapshots, does the chain look like:
A: Current -> Snap2 -> Snap1 \ external data
or B:
Current -> Snap2 -> Snap1 \ \ \ ext-dat2 ext-dat1 ext-dat
This is the correct situation as the store is an per-image property. Any level in the backing chain may or may not have it depending on how you create the image. The external data store write permission must mirror the permission of the image it belongs to, so that if you are e.g. committing one of the snapshots the backing store must be turned writable as qemu will write the data into it.
On 12/9/19 1:50 AM, Christian Ehrhardt wrote:
On Fri, Oct 11, 2019 at 9:13 PM Cole Robinson <crobinso@redhat.com <mailto:crobinso@redhat.com>> wrote:
Teach virt-aa-helper how to label a qcow2 data_file, tracked internally as externalDataStore. It should be treated the same as its sibling disk image
Signed-off-by: Cole Robinson <crobinso@redhat.com
<mailto:crobinso@redhat.com>>
--- Compiled but not runtime tested, I don't have an apparmor setup
src/security/virt-aa-helper.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/src/security/virt-aa-helper.c b/src/security/virt-aa-helper.c index 509187ac36..fe6fa12550 100644 --- a/src/security/virt-aa-helper.c +++ b/src/security/virt-aa-helper.c @@ -949,6 +949,10 @@ storage_source_add_files(virStorageSourcePtr src, if (add_file_path(tmp, depth, buf) < 0) return -1;
+ if (src->externalDataStore && + storage_source_add_files(src->externalDataStore, buf, depth) < 0) + return -1; +
After thinking twice about it ack to carry over depth as only the first layer should only ever need write permissions on those extra files as well.
But I'm unsure about using "src->externalDataStore". After all this does initialize "tmp = src". And then iterates the (potential) backing chain. That way each loop iteration has a different "tmp" along the backing chain but "src" will always point to the first entry.
It comes down to a detail question about the design of external data in qcow. In a case with a base file and two snapshots, does the chain look like:
A: Current -> Snap2 -> Snap1 \ external data
or B:
Current -> Snap2 -> Snap1 \ \ \ ext-dat2 ext-dat1 ext-dat
or C:
Current -> Snap2 -> Snap1 \ external data
Depending on that it should IMHO be a) call storage_source_add_files outside the loop and with depth arg always set to zero b+c) call storage_source_add_files with tmp instead of src as argument (also use tmp in the check if externalDataStore exists)
Indeed, it should be using tmp instead of src, nicely spotted. I'll send a v2. Thankfully the already committed selinux code got it right - Cole
participants (3)
-
Christian Ehrhardt -
Cole Robinson -
Peter Krempa