When enable user-remap, using --devices flage, the UID and GID of the device become invalid.

[aa624545345]

When enable user-remap, using flage "--devices" to map a device , the UID and GID of the device become invalid.

daemon.json:

{
   "registry-mirrors": [
    "http://hub-mirror.c.163.com",
    "https://mirror.ccs.tencentyun.com",
    "https://registry.docker-cn.com",
    "http://public-docker-virtual.artxa.zte.com.cn"
  ],
  "insecure-registries": [
    "public-docker-virtual.artxa.zte.com.cn",
    "0.0.0.0/0",
    "::/0"
  ],
  "storage-opts": [
    "overlay2.override_kernel_check=true"
  ],
  "storage-driver": "overlay2",
  "log-opts": {
    "max-size": "10M",
    "max-file": "5"
  },
  "debug": true,
  "userns-remap": "dockeruser"
}

use "--devices" to map a device to a container, you can see below that Uid and Gid of this device is invalid.

[root@LIN-]# docker run --name qc --rm --device=/dev/dm-0:/dev/dm-0:rwm -ti busybox sh
/ # stat /dev/dm-0 
  File: /dev/dm-0
  Size: 0         	Blocks: 0          IO Block: 4096   block special file
Device: 6h/6d	Inode: 20591       Links: 1     Device type: fd,0
Access: (0660/brw-rw----)  Uid: (65534/  nobody)   Gid: (65534/  nobody)
Access: 2022-08-31 04:18:37.684098967 +0000
Modify: 2022-08-04 17:23:28.080000000 +0000
Change: 2022-08-04 17:23:28.080000000 +0000

In the container, the correct UID range is [165536, 165536+65536]:

/ # cat /proc/1/uid_map 
         0     165536      65536

however, for the config of this container:

    260         "devices": [
    261             {
    262                 "path": "/dev/dm-0",
    263                 "type": "b",
    264                 "major": 253,
    265                 "minor": 0,
    266                 "fileMode": 25008,
    267                 "uid": 0,
    268                 "gid": 6
    269             }
    270         ],

uid of this device is set to 0.