CVE-2023-52749

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> spi: Fix null dereference on suspend<br /> <br /> A race condition exists where a synchronous (noqueue) transfer can be<br /> active during a system suspend. This can cause a null pointer<br /> dereference exception to occur when the system resumes.<br /> <br /> Example order of events leading to the exception:<br /> 1. spi_sync() calls __spi_transfer_message_noqueue() which sets<br /> ctlr-&gt;cur_msg<br /> 2. Spi transfer begins via spi_transfer_one_message()<br /> 3. System is suspended interrupting the transfer context<br /> 4. System is resumed<br /> 6. spi_controller_resume() calls spi_start_queue() which resets cur_msg<br /> to NULL<br /> 7. Spi transfer context resumes and spi_finalize_current_message() is<br /> called which dereferences cur_msg (which is now NULL)<br /> <br /> Wait for synchronous transfers to complete before suspending by<br /> acquiring the bus mutex and setting/checking a suspend flag.