Comment 43 for bug 1742675

Thanks for the suggestion @kaihengfeng. I installed linux-generic-hwe-16.04-edge, which gave me a working 4.15.0-23-generic after a reboot.

The log from 4.13.0-45 failed at this point:

[ 2.444002] DMAR-IR: IOAPIC id 10 under DRHD base 0xdfffe000 IOMMU 0
[ 2.500002] DMAR-IR: IOAPIC id 9 under DRHD base 0xfedc0000 IOMMU 1
[ 2.556002] DMAR-IR: IOAPIC id 8 under DRHD base 0xfedc0000 IOMMU 1
[ 2.560000] DMAR-IR: Enabled IRQ remapping in xapic mode
[ 2.616002] Switched APIC routing to physical flat.
[ 2.620000] BUG: unable to handle kernel NULL pointer dereference at (null)
[ 2.620000] IP: __bitmap_intersects+0x10/0x70

and the same section of dmesg from the working 4.15.0-23 is:

[ 0.000000] DMAR-IR: IOAPIC id 10 under DRHD base 0xdfffe000 IOMMU 0
[ 0.000000] DMAR-IR: IOAPIC id 9 under DRHD base 0xfedc0000 IOMMU 1
[ 0.000000] DMAR-IR: IOAPIC id 8 under DRHD base 0xfedc0000 IOMMU 1
[ 0.000000] DMAR-IR: Enabled IRQ remapping in xapic mode
[ 0.000000] Switched APIC routing to physical flat.
[ 0.000000] ..TIMER: vector=0x30 apic1=0 pin1=2 apic2=-1 pin2=-1
[ 0.020000] tsc: Fast TSC calibration using PIT
[ 0.024000] tsc: Detected 2394.078 MHz processor
[ 0.024000] Calibrating delay loop (skipped), value calculated using timer frequency.. 4788.15 BogoMIPS (lpj=9576312)

... etc.

Maybe that will be useful for someone to track down what causes the crash.