CVE-2023-53007

/// Technical description

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

tracing: Make sure trace_printk() can output as soon as it can be used

Currently trace_printk() can be used as soon as early_trace_init() is

called from start_kernel(). But if a crash happens, and

"ftrace_dump_on_oops" is set on the kernel command line, all you get will

be:

[ 0.456075] <idle>-0 0dN.2. 347519us : Unknown type 6

[ 0.456075] <idle>-0 0dN.2. 353141us : Unknown type 6

[ 0.456075] <idle>-0 0dN.2. 358684us : Unknown type 6

This is because the trace_printk() event (type 6) hasn't been registered

yet. That gets done via an early_initcall(), which may be early, but not

early enough.

Instead of registering the trace_printk() event (and other ftrace events,

which are not trace events) via an early_initcall(), have them registered at

the same time that trace_printk() can be used. This way, if there is a

crash before early_initcall(), then the trace_printk()s will ac

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. 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.

/// References