virtiofsd: check whether lo_map_reserve returns NULL in, main func

In main func, func lo_map_reserve is called without NULL check.
If reallocing new_elems fails in func lo_map_grow, the func
lo_map_reserve may return NULL. We should check whether
lo_map_reserve returns NULL before using it.

Signed-off-by: Haotian Li <lihaotian9@huawei.com>
Signed-off-by: Zhiqiang Liu <liuzhiqiang26@huawei.com>
Message-Id: <48887813-1c95-048c-6d10-48e3dd2bac71@huawei.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

1 files changed, 11 insertions, 1 deletions

diff --git a/tools/virtiofsd/passthrough_ll.c b/tools/virtiofsd/passthrough_ll.c
index 6c64b03f1a..9545a0d174 100644
--- a/tools/virtiofsd/passthrough_ll.c
+++ b/tools/virtiofsd/passthrough_ll.c
@@ -3425,6 +3425,7 @@ int main(int argc, char *argv[])
         .proc_self_fd = -1,
     };
     struct lo_map_elem *root_elem;
+    struct lo_map_elem *reserve_elem;
     int ret = -1;
 
     /* Don't mask creation mode, kernel already did that */
@@ -3444,8 +3445,17 @@ int main(int argc, char *argv[])
      * [1] Root inode
      */
     lo_map_init(&lo.ino_map);
-    lo_map_reserve(&lo.ino_map, 0)->in_use = false;
+    reserve_elem = lo_map_reserve(&lo.ino_map, 0);
+    if (!reserve_elem) {
+        fuse_log(FUSE_LOG_ERR, "failed to alloc reserve_elem.\n");
+        goto err_out1;
+    }
+    reserve_elem->in_use = false;
     root_elem = lo_map_reserve(&lo.ino_map, lo.root.fuse_ino);
+    if (!root_elem) {
+        fuse_log(FUSE_LOG_ERR, "failed to alloc root_elem.\n");
+        goto err_out1;
+    }
     root_elem->inode = &lo.root;
 
     lo_map_init(&lo.dirp_map);