Verified with libfprint 1:1.90.2+tod1-0ubuntu1~20.04.4 and fprintd 1.90.1-1ubuntu1:

(fprintd:61642): fprintd-DEBUG: 14:36:29.714: file_storage_discover_prints() for user 'u' in '/var/lib/fprint/u/synaptics/ea61678c21e3'
(fprintd:61642): fprintd-DEBUG: 14:36:29.717: user 'u' claiming the device: 0
(fprintd:61642): libfprint-synaptics-DEBUG: 14:36:29.831: 26275727182: ../libfprint/drivers/synaptics/synaptics.c:1248
(fprintd:61642): libfprint-synaptics-DEBUG: 14:36:30.110: sequence number is 4
(fprintd:61642): libfprint-SSM-DEBUG: 14:36:30.110: [synaptics] SYNAPTICS_CMD_NUM_STATES entering state 0
(fprintd:61642): libfprint-SSM-DEBUG: 14:36:30.110: [synaptics] SYNAPTICS_CMD_NUM_STATES entering state 1
(fprintd:61642): libfprint-device-DEBUG: 14:36:30.129: Device reported open completion
(fprintd:61642): libfprint-SSM-DEBUG: 14:36:30.129: [synaptics] SYNAPTICS_CMD_NUM_STATES completed successfully
(fprintd:61642): libfprint-device-DEBUG: 14:36:30.129: Completing action 2 in idle!
(fprintd:61642): fprintd-DEBUG: 14:36:30.129: claimed device 0
(fprintd:61642): fprintd-DEBUG: 14:36:30.133: file_storage_discover_prints() for user 'u' in '/var/lib/fprint/u/synaptics/ea61678c21e3'
(fprintd:61642): fprintd-DEBUG: 14:36:30.133: adding finger 5 to the gallery
(fprintd:61642): fprintd-DEBUG: 14:36:30.133: file_storage_print_data_load(): loaded '/var/lib/fprint/u/synaptics/ea61678c21e3/5' Success
(fprintd:61642): fprintd-DEBUG: 14:36:30.133: adding finger 10 to the gallery
(fprintd:61642): fprintd-DEBUG: 14:36:30.133: file_storage_print_data_load(): loaded '/var/lib/fprint/u/synaptics/ea61678c21e3/a' Success
(fprintd:61642): fprintd-DEBUG: 14:36:30.133: start identification device 0
(fprintd:61642): libfprint-synaptics-DEBUG: 14:36:30.133: data is 0x55af48b83920
(fprintd:61642): libfprint-synaptics-DEBUG: 14:36:30.133: data is 0x7f4844001aa0
(fprintd:61642): libfprint-synaptics-DEBUG: 14:36:30.133: 26276028653: ../libfprint/drivers/synaptics/synaptics.c:816
(fprintd:61642): libfprint-synaptics-DEBUG: 14:36:30.133: sequence number is 5
(fprintd:61642): libfprint-SSM-DEBUG: 14:36:30.133: [synaptics] SYNAPTICS_CMD_NUM_STATES entering state 0
(fprintd:61642): libfprint-SSM-DEBUG: 14:36:30.133: [synaptics] SYNAPTICS_CMD_NUM_STATES entering state 1
(fprintd:61642): libfprint-synaptics-DEBUG: 14:36:30.133: Place Finger on the Sensor!
(fprintd:61642): libfprint-SSM-DEBUG: 14:36:30.133: [synaptics] SYNAPTICS_CMD_NUM_STATES entering state 2
(fprintd:61642): libfprint-synaptics-DEBUG: 14:36:32.215: interrupt transfer done
(fprintd:61642): libfprint-SSM-DEBUG: 14:36:32.215: [synaptics] SYNAPTICS_CMD_NUM_STATES entering state 3
(fprintd:61642): libfprint-SSM-DEBUG: 14:36:32.216: [synaptics] SYNAPTICS_CMD_NUM_STATES entering state 4
(fprintd:61642): libfprint-SSM-DEBUG: 14:36:32.216: [synaptics] SYNAPTICS_CMD_NUM_STATES entering state 0
(fprintd:61642): libfprint-SSM-DEBUG: 14:36:32.216: [synaptics] SYNAPTICS_CMD_NUM_STATES entering state 1
(fprintd:61642): libfprint-synaptics-DEBUG: 14:36:32.216: Finger is now on the sensor
(fprintd:61642): libfprint-synaptics-DEBUG: 14:36:32.216: Received message with 0 sequence number 0x91, ignoring!
(fprintd:61642): libfprint-SSM-DEBUG: 14:36:32.216: [synaptics] SYNAPTICS_CMD_NUM_STATES entering state 2
(fprintd:61642): libfprint-synaptics-DEBUG: 14:36:32.331: interrupt transfer done
(fprintd:61642): libfprint-SSM-DEBUG: 14:36:32.331: [synaptics] SYNAPTICS_CMD_NUM_STATES entering state 3
(fprintd:61642): libfprint-SSM-DEBUG: 14:36:32.332: [synaptics] SYNAPTICS_CMD_NUM_STATES entering state 4
(fprintd:61642): libfprint-SSM-DEBUG: 14:36:32.332: [synaptics] SYNAPTICS_CMD_NUM_STATES entering state 0
(fprintd:61642): libfprint-SSM-DEBUG: 14:36:32.332: [synaptics] SYNAPTICS_CMD_NUM_STATES entering state 1
(fprintd:61642): libfprint-SSM-DEBUG: 14:36:32.332: [synaptics] SYNAPTICS_CMD_NUM_STATES entering state 2
(fprintd:61642): libfprint-synaptics-DEBUG: 14:36:32.363: interrupt transfer done
(fprintd:61642): libfprint-SSM-DEBUG: 14:36:32.363: [synaptics] SYNAPTICS_CMD_NUM_STATES entering state 3
(fprintd:61642): libfprint-SSM-DEBUG: 14:36:32.364: [synaptics] SYNAPTICS_CMD_NUM_STATES entering state 4
(fprintd:61642): libfprint-SSM-DEBUG: 14:36:32.364: [synaptics] SYNAPTICS_CMD_NUM_STATES entering state 0
(fprintd:61642): libfprint-SSM-DEBUG: 14:36:32.364: [synaptics] SYNAPTICS_CMD_NUM_STATES entering state 1
(fprintd:61642): libfprint-synaptics-DEBUG: 14:36:32.364: Finger is now on the sensor
(fprintd:61642): libfprint-synaptics-DEBUG: 14:36:32.364: Received message with 0 sequence number 0x91, ignoring!
(fprintd:61642): libfprint-SSM-DEBUG: 14:36:32.364: [synaptics] SYNAPTICS_CMD_NUM_STATES entering state 2
(fprintd:61642): libfprint-synaptics-DEBUG: 14:36:32.659: interrupt transfer done
(fprintd:61642): libfprint-SSM-DEBUG: 14:36:32.659: [synaptics] SYNAPTICS_CMD_NUM_STATES entering state 3
(fprintd:61642): libfprint-SSM-DEBUG: 14:36:32.660: [synaptics] SYNAPTICS_CMD_NUM_STATES entering state 4
(fprintd:61642): libfprint-SSM-DEBUG: 14:36:32.660: [synaptics] SYNAPTICS_CMD_NUM_STATES entering state 0
(fprintd:61642): libfprint-SSM-DEBUG: 14:36:32.660: [synaptics] SYNAPTICS_CMD_NUM_STATES entering state 1
(fprintd:61642): libfprint-synaptics-DEBUG: 14:36:32.660: data is 0x55af48b83920
(fprintd:61642): libfprint-device-DEBUG: 14:36:32.660: Device reported identify result
(fprintd:61642): libfprint-device-DEBUG: 14:36:32.660: Device reported identify completion
(fprintd:61642): libfprint-SSM-DEBUG: 14:36:32.660: [synaptics] SYNAPTICS_CMD_NUM_STATES completed successfully
(fprintd:61642): libfprint-device-DEBUG: 14:36:32.660: Completing action 6 in idle!
(fprintd:61642): fprintd-DEBUG: 14:36:32.660: verify_cb: result verify-match
(fprintd:61642): libfprint-synaptics-DEBUG: 14:36:32.664: 26278559845: ../libfprint/drivers/synaptics/synaptics.c:1272
(fprintd:61642): libfprint-synaptics-DEBUG: 14:36:32.664: sequence number is 6
(fprintd:61642): libfprint-SSM-DEBUG: 14:36:32.664: [synaptics] SYNAPTICS_CMD_NUM_STATES entering state 0
(fprintd:61642): libfprint-SSM-DEBUG: 14:36:32.664: [synaptics] SYNAPTICS_CMD_NUM_STATES entering state 1
(fprintd:61642): libfprint-synaptics-DEBUG: 14:36:32.664: Fingerprint sensor ready to be powered down
(fprintd:61642): libfprint-device-DEBUG: 14:36:32.664: Device reported close completion
(fprintd:61642): libfprint-SSM-DEBUG: 14:36:32.664: [synaptics] SYNAPTICS_CMD_NUM_STATES completed successfully
(fprintd:61642): libfprint-device-DEBUG: 14:36:32.664: Completing action 3 in idle!
(fprintd:61642): fprintd-DEBUG: 14:36:32.664: released device 0

No crash during identification.