大家好，我在Ubuntu 22.04.03上安装的Cisco AnyConnect Secure Mobility Client 4.10.07061之前一直正常连接依赖Office365认证的内部VPN服务器，但最近突然出问题了——输入VPN服务器地址后弹出的认证窗口直接变成空白，完全没法完成登录操作。

我查看了系统日志（执行命令：cat /var/sys/syslog），相关日志内容如下：

Oct 16 16:38:29 UbuL4479 acvpnui[10035]: Message type prompt sent to the user: Please complete the authentication process in the AnyConnect Login window.

...

Oct 16 16:38:30 UbuL4479 acvpnui[10035]: Function: launchBrowser File: ../../../vpn/WebHelper/Plugin/WebHelperPluginImpl.cpp Line: 783 Browser process launched successfully [pid 10068]

Oct 16 16:38:30 UbuL4479 com.cisco.anyconnect.gui.desktop[10112]: KMS: DRM_IOCTL_MODE_CREATE_DUMB failed: Permission denied

Oct 16 16:38:30 UbuL4479 com.cisco.anyconnect.gui.desktop[10112]: Failed to create GBM buffer of size 1000x600: Permission denied

Oct 16 16:38:30 UbuL4479 com.cisco.anyconnect.gui.desktop[10112]: KMS: DRM_IOCTL_MODE_CREATE_DUMB failed: Permission denied

Oct 16 16:38:30 UbuL4479 com.cisco.anyconnect.gui.desktop[10112]: Failed to create GBM buffer of size 1000x600: Permission denied

Oct 16 16:38:30 UbuL4479 com.cisco.anyconnect.gui.desktop[10112]: KMS: DRM_IOCTL_MODE_CREATE_DUMB failed: Permission denied

Oct 16 16:38:30 UbuL4479 com.cisco.anyconnect.gui.desktop[10112]: Failed to create GBM buffer of size 1000x600: Permission denied

Oct 16 16:38:30 UbuL4479 com.cisco.anyconnect.gui.desktop[10112]: Failed to create EGL images for DMABufs with file descriptors -1, -1 and -1

Oct 16 16:38:30 UbuL4479 rtkit-daemon[2254]: Supervising 12 threads of 6 processes of 1 users.

Oct 16 16:38:30 UbuL4479 rtkit-daemon[2254]: Successfully made thread 10129 of process 10112 owned by '1000' RT at priority 5.

Oct 16 16:38:30 UbuL4479 rtkit-daemon[2254]: Supervising 13 threads of 7 processes of 1 users.

Oct 16 16:38:30 UbuL4479 rtkit-daemon[2254]: Supervising 13 threads of 7 processes of 1 users.

Oct 16 16:38:30 UbuL4479 rtkit-daemon[2254]: Successfully made thread 10169 of process 10112 owned by '1000' RT at priority 5.

Oct 16 16:38:30 UbuL4479 rtkit-daemon[2254]: Supervising 14 threads of 7 processes of 1 users.

Oct 16 16:38:31 UbuL4479 kernel: [  586.958683] audit: type=1107 audit(1697495911.042:149): pid=1391 uid=103 auid=4294967295 ses=4294967295 subj=unconfined msg='apparmor="DENIED" operation="dbus_signal"  bus="system" path="/org/freedesktop/login1" interface="org.freedesktop.DBus.Properties" member="PropertiesChanged" name=":1.13" mask="receive" pid=7633 label="snap.firefox.firefox" peer_pid=1449 peer_label="unconfined"

Oct 16 16:38:31 UbuL4479 kernel: [  586.958683]  exe="/usr/bin/dbus-daemon" sauid=103 hostname=? addr=? terminal=?'

Oct 16 16:38:31 UbuL4479 WebKitNetworkPr[10109]: gssapi step failed: No credentials were supplied, or the credentials were unavailable or inaccessible: SPNEGO cannot find mechanisms to negotiate

Oct 16 16:38:36 UbuL4479 kernel: [  591.976441] audit: type=1107 audit(1697495916.062:150): pid=1391 uid=103 auid=4294967295 ses=4294967295 subj=unconfined msg='apparmor="DENIED" operation="dbus_signal"  bus="system" path="/org/freedesktop/login1" interface="org.freedesktop.DBus.Properties" member="PropertiesChanged" name=":1.13" mask="receive" pid=7633 label="snap.firefox.firefox" peer_pid=1449 peer_label="unconfined"

Oct 16 16:38:36 UbuL4479 kernel: [  591.976441]  exe="/usr/bin/dbus-daemon" sauid=103 hostname=? addr=? terminal=?'

从日志里能看到几个关键异常：AnyConnect的桌面进程反复出现DRM_IOCTL_MODE_CREATE_DUMB failed: Permission denied和GBM缓冲区创建失败的报错，还有WebKit的GSSAPI认证步骤出错。我已经试过重启AnyConnect客户端、重启系统，但都没解决问题，有没有遇到过类似情况的朋友能给点排查思路或者解决方案？

备注：内容来源于stack exchange，提问作者dax