1:18 p.m.
There's a commit inside of (yet-unreleased) libcap-ng which marks some
functions as 'warned unused result'. Fedora rawhide already picked up
the commit, but since we are not checking for all retvals we got a build
failure on rawhide.
https://src.fedoraproject.org/rpms/libcap-ng/c/fed9b23c8d0020e07c937a3ac0...
Green pipeline:
https://gitlab.com/MichalPrivoznik/libvirt/-/pipelines/999435445
Michal Prívozník (2):
lxc_container: Check retval of capng_get_caps_process()
virutil: Check retval of capng_apply()
src/lxc/lxc_container.c | 8 +++++++-
src/util/virutil.c | 8 ++++++--
2 files changed, 13 insertions(+), 3 deletions(-)
--
2.41.0
1:18 p.m.
New subject: [PATCH 1/2] lxc_container: Check retval of capng_get_caps_process()
Added in v0.6.5~14 the call to capng_get_caps_process() inside of
lxcContainerDropCapabilities() is not really explained in the
commit message. But looking into the libcap-ng sources it's to
initialize the internal state of the library.
But with recent libcap-ng commit [1] (which some bleeding edge
distros - like Fedora rawhide - already picked up) the function
has been marked as 'warn unused result'. Well, check for its
retval then.
1:
https://github.com/stevegrubb/libcap-ng/commit/a0743c335c9a16a2fda9b25120...
Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com>
---
src/lxc/lxc_container.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/src/lxc/lxc_container.c b/src/lxc/lxc_container.c
index 21220661f7..4c37fcd012 100644
--- a/src/lxc/lxc_container.c
+++ b/src/lxc/lxc_container.c
@@ -1725,7 +1725,13 @@ static int lxcContainerDropCapabilities(virDomainDef *def,
CAP_SYSLOG,
CAP_WAKE_ALARM};
- capng_get_caps_process();
+ /* Init the internal state of capng */
+ if ((ret = capng_get_caps_process()) < 0) {
+ virReportError(VIR_ERR_INTERNAL_ERROR,
+ _("Failed to get current process capabilities %1$d"),
+ ret);
+ return -1;
+ }
/* Make sure we drop everything if required by the user */
if (policy == VIR_DOMAIN_CAPABILITIES_POLICY_DENY)
--
2.41.0
1:18 p.m.
New subject: [PATCH 2/2] virutil: Check retval of capng_apply()
Inside of virSetUIDGIDWithCaps() there's a naked call to
capng_apply(), i.e. without any retval check. This is potentially
dangerous as capng_apply() may fail. Do the check and report an
error.
This also fixes the build on bleeding edge distros - like Fedora
rawhide - where the function is declared with 'warn unused
result' [1].
1:
https://github.com/stevegrubb/libcap-ng/commit/a0743c335c9a16a2fda9b25120...
Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com>
---
src/util/virutil.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/src/util/virutil.c b/src/util/virutil.c
index b5b65fb415..edc39b981f 100644
--- a/src/util/virutil.c
+++ b/src/util/virutil.c
@@ -1200,8 +1200,12 @@ virSetUIDGIDWithCaps(uid_t uid, gid_t gid, gid_t *groups, int
ngroups,
* do this if we failed to get the capability above, so ignore the
* return value.
*/
- if (!need_setpcap)
- capng_apply(CAPNG_SELECT_BOUNDS);
+ if (!need_setpcap &&
+ (capng_ret = capng_apply(CAPNG_SELECT_BOUNDS)) < 0) {
+ virReportError(VIR_ERR_INTERNAL_ERROR,
+ _("cannot apply process capabilities %1$d"),
capng_ret);
+ return -1;
+ }
/* Drop the caps that allow setuid/gid (unless they were requested) */
if (need_setgid)
--
2.41.0
1:27 p.m.
On a Monday in 2023, Michal Privoznik wrote:
There's a commit inside of (yet-unreleased) libcap-ng which marks
some
functions as 'warned unused result'. Fedora rawhide already picked up
the commit, but since we are not checking for all retvals we got a build
failure on rawhide.
https://src.fedoraproject.org/rpms/libcap-ng/c/fed9b23c8d0020e07c937a3ac0...
Green pipeline:
https://gitlab.com/MichalPrivoznik/libvirt/-/pipelines/999435445
Michal Prívozník (2):
lxc_container: Check retval of capng_get_caps_process()
virutil: Check retval of capng_apply()
src/lxc/lxc_container.c | 8 +++++++-
src/util/virutil.c | 8 ++++++--
2 files changed, 13 insertions(+), 3 deletions(-)
Please add a separating ':' between "capabilities" and the number,
as we do elsewhere when printing capng's error codes.
Reviewed-by: Ján Tomko <jtomko(a)redhat.com>
Jano
1:31 p.m.
On Mon, Sep 11, 2023 at 12:18:28PM +0200, Michal Privoznik wrote:
There's a commit inside of (yet-unreleased) libcap-ng which marks
some
functions as 'warned unused result'. Fedora rawhide already picked up
the commit, but since we are not checking for all retvals we got a build
failure on rawhide.
https://src.fedoraproject.org/rpms/libcap-ng/c/fed9b23c8d0020e07c937a3ac0...
Green pipeline:
https://gitlab.com/MichalPrivoznik/libvirt/-/pipelines/999435445
Michal Prívozník (2):
lxc_container: Check retval of capng_get_caps_process()
virutil: Check retval of capng_apply()
Reviewed-by: Martin Kletzander <mkletzan(a)redhat.com>
Checking return values is nicer anyway.
src/lxc/lxc_container.c | 8 +++++++-
src/util/virutil.c | 8 ++++++--
2 files changed, 13 insertions(+), 3 deletions(-)
--
2.41.0
587
days inactive
587
days old
4 comments
3 participants
participants (3)
-
Ján Tomko -
Martin Kletzander -
Michal Privoznik