bisecting fixing commit since a844dc4c544291470aa69edbe2434b040794e269
building syzkaller on 4b83c8fbed7b9cea831be880ec8aa1098b465f25
testing commit a844dc4c544291470aa69edbe2434b040794e269 with gcc (GCC) 8.1.0
kernel signature: 0980084f9a7ac7feb1cde34c5fd24c8047c64e2e8a80ea6e530f07e857ac160c
all runs: crashed: BUG: unable to handle kernel NULL pointer dereference in mem_serial_out
testing current HEAD 4139fb08c05fec734f85a99e8b7d99dc12b1b68c
testing commit 4139fb08c05fec734f85a99e8b7d99dc12b1b68c with gcc (GCC) 8.1.0
kernel signature: b3ceb2937c739f9df254860ad25097bffd2af25f13d7f3a49d9684faaa63f673
all runs: boot failed: WARNING in kvm_mmu_set_mmio_spte_mask
revisions tested: 2, total time: 30m25.893017836s (build: 16m6.870493863s, test: 13m42.947406426s)
bisection is inconclusive, the first good commit could be any of:
a844dc4c544291470aa69edbe2434b040794e269
4139fb08c05fec734f85a99e8b7d99dc12b1b68c