CVE-2023-52872: linux kernel vulnerability

In the Linux kernel, the following vulnerability has been resolved: tty: n_gsm: fix race condition in status line change on dead connections gsm_cleanup_mux() cleans up the gsm by closing all DLCIs, stopping all timers, removing the virtual tty devices and clearing the data queues. This procedure, however, may cause subsequent changes of the virtual modem status lines of a DLCI. More data is being added the outgoing data queue and the deleted kick timer is restarted to handle this. At this point many resources have already been removed by the cleanup procedure. Thus, a kernel panic occurs. Fix this by proving in gsm_modem_update() that the cleanup procedure has not been started and the mux is still alive. Note that writing to a virtual tty is already protected by checks against the DLCI specific connection state.
CVE-2023-52872CVSS 5.5Linux

CVE-2023-52872: linux kernel vulnerability

In the Linux kernel, the following vulnerability has been resolved: tty: n_gsm: fix race condition in status line change on dead connections gsm_cleanup_mux() cleans up the gsm by closing all DLCIs, stopping all timers, removing the virtual tty devices and clearing the data queues. This procedure, however, may cause subsequent changes of the virtual modem status lines of a DLCI. More data is being added the outgoing data queue and the deleted kick timer is restarted to handle this. At this point many resources have already been removed by the cleanup procedure. Thus, a kernel panic occurs. Fix this by proving in gsm_modem_update() that the cleanup procedure has not been started and the mux is still alive. Note that writing to a virtual tty is already protected by checks against the DLCI specific connection state.

CVSS
5.5 MEDIUM
EPSS
6.8%
Known exploited
not in KEV
Product
linux kernel

What is known

In the Linux kernel, the following vulnerability has been resolved: tty: n_gsm: fix race condition in status line change on dead connections gsm_cleanup_mux() cleans up the gsm by closing all DLCIs, stopping all timers, removing the virtual tty devices and clearing the data queues. This procedure, however, may cause subsequent changes of the virtual modem status lines of a DLCI. More data is being added the outgoing data queue and the deleted kick timer is restarted to handle this. At this point many resources have already been removed by the cleanup procedure. Thus, a kernel panic occurs. Fix this by proving in gsm_modem_update() that the cleanup procedure has not been started and the mux is still alive. Note that writing to a virtual tty is already protected by checks against the DLCI specific connection state.

Sources

Security newsletter

Get new CVE alerts before they become an incident

We send selected infrastructure threats in English, with practical notes for DataHouse environments.

  • DataHouse: server administration and secure cloud
  • Hostilla.pl: hosting and mail services
  • SecDNS.pl: free DNS security layer