Technical Tip: Kernel Panic at NP7 drivers on FortiGate Causes Continuous Device Reboots

[vpalli]

Description	The article describes an issue related to NP7 drivers that causes a Kernel Panic on FortiGate and results in continuous device reboots.
Scope	FortiGate v7.4.x.
Solution	Kernel crash log can be accessed through a console session to the FortiGate while the device is rebooting or via COMlog on supported devices. For instructions on enabling COMlog on a supported device, refer to Technical Tip: How to use the COMLog feature. On v7.4.x, FortiGates configured with the default-qos-type set to 'shaping' may experience continuous reboots, and the following log may be seen in the COMlog or console session. (Press 'a' to accept):kernel BUG at drivers/net/np7/./qos/np7_sys_qtm.c:303! invalid opcode: 0000 [1] SMP CPU: 2 PID: 3515 Comm: authd4 Tainted: P 4.19.13 1 RIP: 0010:np7_sys_qtm_qqid_sch0_alloc+0x28e/0x300 [filter4] Code: 66 25 fc 1f 48 89 f2 09 c8 66 89 06 48 89 de e8 a8 ca ff ff 31 c0 45 84 ff 74 1f 48 83 c4 18 5b 41 5c 41 5d 41 5e 41 5f 5d c3 <0f> 0b 41 0f b7 57 10 66 89 50 2e e9 ff fe ff ff 41 0f b7 cd 4f 8d For additional information about the 'default-qos-type' configuration on FortiGate, refer to the following documents: Configuring NP7 traffic shaping  Configuring default-qos-type {policing | shaping}  The issue is resolved in v7.6.1 and scheduled for a fix in v7.4.8. As a workaround, configure the NP7 traffic shaping to use 'Policing' instead of 'Shaping'. The FortiGate restarts after changing this setting. config system npu     set default-qos-type policing end If the device is rebooting frequently and does not allow for the configuration change, follow these steps: Interrupt the boot sequence to format the unit. Refer to Technical Tip: Formatting and loading FortiGate firmware image using TFTP. Load the same firmware version as before using TFTP. Modify the most recent known good configuration file to set the default QoS type to 'Policing.' Load the modified configuration file onto the unit using the Restore System Configuration option on GUI. Refer to Backing up and restoring configurations from the GUI. If Steps 1-4 are not possible, unplug all of the cables except the MGMT interface to change the configuration. This will prevent traffic from being processed to the QTM module. If further information is needed, open a ticket with TAC.