[PULL 2/5] virtiofsd: Check capability calls

["Dr. David Alan Gilbert (git)" <dgilbert@redhat.com>]

From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>

Check the capability calls worked.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Message-Id: <20200629115420.98443-3-dgilbert@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
 tools/virtiofsd/passthrough_ll.c | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/tools/virtiofsd/passthrough_ll.c b/tools/virtiofsd/passthrough_ll.c
index e373e3b36e..99d562046a 100644
--- a/tools/virtiofsd/passthrough_ll.c
+++ b/tools/virtiofsd/passthrough_ll.c
@@ -2589,7 +2589,7 @@ static void setup_capabilities(void)
      */
     capng_setpid(syscall(SYS_gettid));
     capng_clear(CAPNG_SELECT_BOTH);
-    capng_updatev(CAPNG_ADD, CAPNG_PERMITTED | CAPNG_EFFECTIVE,
+    if (capng_updatev(CAPNG_ADD, CAPNG_PERMITTED | CAPNG_EFFECTIVE,
             CAP_CHOWN,
             CAP_DAC_OVERRIDE,
             CAP_DAC_READ_SEARCH,
@@ -2599,11 +2599,21 @@ static void setup_capabilities(void)
             CAP_SETUID,
             CAP_MKNOD,
             CAP_SETFCAP,
-            -1);
+            -1)) {
+        fuse_log(FUSE_LOG_ERR, "%s: capng_updatev failed\n", __func__);
+        exit(1);
+    }
 
-    capng_apply(CAPNG_SELECT_BOTH);
+    if (capng_apply(CAPNG_SELECT_BOTH)) {
+        fuse_log(FUSE_LOG_ERR, "%s: capng_apply failed\n", __func__);
+        exit(1);
+    }
 
     cap.saved = capng_save_state();
+    if (!cap.saved) {
+        fuse_log(FUSE_LOG_ERR, "%s: capng_save_state failed\n", __func__);
+        exit(1);
+    }
     pthread_mutex_unlock(&cap.mutex);
 }
 
-- 
2.26.2