https://devzone.nordicsemi.com/f/nordic-q-a/76374/spm-overwrites-user-ram-variablesUsing gdb watchpoints I was able to see that running spm_request_random_number() (which is executed in sys_rand32_get) changes content of first byte of backend_cb_log_backend_custom. This is fragment of zephyr.map file: ... .bss.fp_context_buffer 0x0000000020015db4en-USTelligent Community 13Tue, 22 Jun 2021 14:40:25 GMThttps://devzone.nordicsemi.com/thread/316523?ContentTypeID=1Tue, 22 Jun 2021 14:40:25 GMT137ad170-7792-4731-bb38-c0d22fbe4515:bea3cd81-6d54-42fc-9e38-f0de95a57985mniestroj<p>I confirm, that it does fix this bug, thanks!</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/315851?ContentTypeID=1Thu, 17 Jun 2021 11:46:17 GMT137ad170-7792-4731-bb38-c0d22fbe4515:130ea5af-d483-4482-bafd-4192c5a27b16Marte Myrvold<p>Hi,</p> <p>I just wanted to inform you that there&nbsp;has been made a&nbsp;fix for this bug&nbsp;<a href="https://github.com/nrfconnect/sdk-nrf/pull/4892">here</a>.</p> <p>Best regards,</p> <p>Marte</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/315611?ContentTypeID=1Wed, 16 Jun 2021 12:45:04 GMT137ad170-7792-4731-bb38-c0d22fbe4515:d6fa1c37-60b5-4b34-ad88-2d5ffd7ae9e5Marte Myrvold<p>Hi,</p> <p>Thank you for reporting this bug and for providing&nbsp;information about which commit it was most likely introduced in!</p> <p>I have reported this internally to our developers, and they are looking into it.</p> <p>Best regards,</p> <p>Marte</p><div style="clear:both;"></div>