diff options
| -rw-r--r-- | tools/virtiofsd/fuse_virtio.c | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/tools/virtiofsd/fuse_virtio.c b/tools/virtiofsd/fuse_virtio.c index 3b6d16a041..9e5537506c 100644 --- a/tools/virtiofsd/fuse_virtio.c +++ b/tools/virtiofsd/fuse_virtio.c @@ -949,6 +949,22 @@ int virtio_session_mount(struct fuse_session *se) { int ret; + /* + * Test that unshare(CLONE_FS) works. fv_queue_worker() will need it. It's + * an unprivileged system call but some Docker/Moby versions are known to + * reject it via seccomp when CAP_SYS_ADMIN is not given. + * + * Note that the program is single-threaded here so this syscall has no + * visible effect and is safe to make. + */ + ret = unshare(CLONE_FS); + if (ret == -1 && errno == EPERM) { + fuse_log(FUSE_LOG_ERR, "unshare(CLONE_FS) failed with EPERM. If " + "running in a container please check that the container " + "runtime seccomp policy allows unshare.\n"); + return -1; + } + ret = fv_create_listen_socket(se); if (ret < 0) { return ret; |