Re: [PATCH V2] security: Ensure file exists before attempting to restore label
On 4/2/24 00:14, Jim Fehlig wrote:
When performing an install, it's common for tooling such as
virt-install
to remove the install kernel/initrd once they are successfully booted and
the domain has been redefined to boot without them. After the installation
is complete and the domain is rebooted/shutdown, the DAC and selinux
security drivers attempt to restore labels on the now deleted files. It's
harmles wrt functionality, but results in error messages such as
Mar 08 12:40:37 virtqemud[5639]: internal error: child reported (status=125): unable to
stat: /var/lib/libvirt/boot/vir>
Mar 08 12:40:37 virtqemud[5639]: unable to stat:
/var/lib/libvirt/boot/virtinst-yvp19moo-linux: No such file or directo>
Mar 08 12:40:37 virtqemud[5639]: Unable to run security manager transaction
Add a check for file existence to the virSecurity*RestoreFileLabel functions,
and avoid relabeling if the file is no longer available. Skipping the restore
caused failures in qemusecuritytest, which mocks stat, chown, etc as part of
ensuring the security drivers properly restore labels. virFileExists is now
mocked in qemusecuritymock.c to return true when passed a file previously
seen by the mocked stat, chown, etc functions.
Signed-off-by: Jim Fehlig <jfehlig(a)suse.com>
---
src/security/security_dac.c | 3 +++
src/security/security_selinux.c | 2 ++
tests/qemusecuritymock.c | 18 ++++++++++++++++++
3 files changed, 23 insertions(+)
Looks better now, thanks!
diff --git a/src/security/security_dac.c
b/src/security/security_dac.c
index 567be4bd23..4e850e219e 100644
--- a/src/security/security_dac.c
+++ b/src/security/security_dac.c
@@ -825,6 +825,9 @@ virSecurityDACRestoreFileLabelInternal(virSecurityManager *mgr,
virStorageSourceIsLocalStorage(src))
path = src->path;
+ if (!virFileExists(path))
+ return 0;
+
/* Be aware that this function might run in a separate process.
* Therefore, any driver state changes would be thrown away. */
diff --git a/src/security/security_selinux.c b/src/security/security_selinux.c
index b49af26e49..aaec34ff8b 100644
--- a/src/security/security_selinux.c
+++ b/src/security/security_selinux.c
@@ -1488,6 +1488,8 @@ virSecuritySELinuxRestoreFileLabel(virSecurityManager *mgr,
*/
if (!path)
return 0;
+ if (!virFileExists(path))
+ return 0;
VIR_INFO("Restoring SELinux context on '%s'", path);
diff --git a/tests/qemusecuritymock.c b/tests/qemusecuritymock.c
index 80d59536b1..bb0a85544b 100644
--- a/tests/qemusecuritymock.c
+++ b/tests/qemusecuritymock.c
@@ -382,6 +382,24 @@ int virFileUnlock(int fd G_GNUC_UNUSED,
}
+bool virFileExists(const char *path G_GNUC_UNUSED)
This argument is used, so please drop the unused annotation.
+{
+ VIR_LOCK_GUARD lock = virLockGuardLock(&m);
+
+ if (getenv(ENVVAR) == NULL)
+ return access(path, F_OK) == 0;
I wonder whether we should call real virFileExists() here. That way, if
a test would chain mocks they can work (though both would probably be
mocking access()). I'll leave it up to you whether you want to squash in
the following:
diff --git i/tests/qemusecuritymock.c w/tests/qemusecuritymock.c
index bb0a85544b..92e7c9ac26 100644
--- i/tests/qemusecuritymock.c
+++ w/tests/qemusecuritymock.c
@@ -66,6 +66,8 @@ static int (*real_close)(int fd);
static int (*real_setfilecon_raw)(const char *path, const char *context);
static int (*real_getfilecon_raw)(const char *path, char **context);
#endif
+static bool (*real_virFileExists)(const char *file);
+
/* Global mutex to avoid races */
@@ -123,6 +125,7 @@ init_syms(void)
VIR_MOCK_REAL_INIT(setfilecon_raw);
VIR_MOCK_REAL_INIT(getfilecon_raw);
#endif
+ VIR_MOCK_REAL_INIT(virFileExists);
/* Intentionally not calling init_hash() here */
}
@@ -382,12 +385,12 @@ int virFileUnlock(int fd G_GNUC_UNUSED,
}
-bool virFileExists(const char *path G_GNUC_UNUSED)
+bool virFileExists(const char *path)
{
VIR_LOCK_GUARD lock = virLockGuardLock(&m);
if (getenv(ENVVAR) == NULL)
- return access(path, F_OK) == 0;
+ return real_virFileExists(path);
init_hash();
if (virHashHasEntry(chown_paths, path))
Reviewed-by: Michal Privoznik <mprivozn(a)redhat.com>
Michal