CVE-2023-52749

/// Technical description

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

spi: Fix null dereference on suspend

A race condition exists where a synchronous (noqueue) transfer can be

active during a system suspend. This can cause a null pointer

dereference exception to occur when the system resumes.

Example order of events leading to the exception:

1. spi_sync() calls __spi_transfer_message_noqueue() which sets

ctlr->cur_msg

2. Spi transfer begins via spi_transfer_one_message()

3. System is suspended interrupting the transfer context

4. System is resumed

6. spi_controller_resume() calls spi_start_queue() which resets cur_msg

to NULL

7. Spi transfer context resumes and spi_finalize_current_message() is

called which dereferences cur_msg (which is now NULL)

Wait for synchronous transfers to complete before suspending by

acquiring the bus mutex and setting/checking a suspend flag.

/// 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