CVE-2023-53560

Technical Description

In the Linux kernel, the following vulnerability has been resolved:

tracing/histograms: Add histograms to hist_vars if they have referenced variables

Hist triggers can have referenced variables without having direct

variables fields. This can be the case if referenced variables are added

for trigger actions. In this case the newly added references will not

have field variables. Not taking such referenced variables into

consideration can result in a bug where it would be possible to remove

hist trigger with variables being refenced. This will result in a bug

that is easily reproducable like so

$ cd /sys/kernel/tracing

$ echo 'synthetic_sys_enter char[] comm; long id' >> synthetic_events

$ echo 'hist:keys=common_pid.execname,id.syscall:vals=hitcount:comm=common_pid.execname' >> events/raw_syscalls/sys_enter/trigger

$ echo 'hist:keys=common_pid.execname,id.syscall:onmatch(raw_syscalls.sys_enter).synthetic_sys_enter($comm, id)' >> events/raw_syscalls/sys_enter/trigger

$ echo '!hist:keys

Remediation

Check the references section for vendor advisories and patches from linux. Update linux_kernel to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

Affected Products

References