bisecting fixing commit since 01364dad1d4577e27a57729d41053f661bb8a5b9
building syzkaller on a34e2c332411388ed2b3f6f1a3acdc062feceb79
testing commit 01364dad1d4577e27a57729d41053f661bb8a5b9 with gcc (GCC) 8.1.0
kernel signature: cb22b3c3509b2576a156a7a9b6fc8e660da71efab26eb77488c4e2ce916c9cd1
all runs: crashed: BUG: unable to handle kernel NULL pointer dereference in l2tp_session_free
testing current HEAD 4139fb08c05fec734f85a99e8b7d99dc12b1b68c
testing commit 4139fb08c05fec734f85a99e8b7d99dc12b1b68c with gcc (GCC) 8.1.0
kernel signature: 69a53130b12ed11cfde7833ba94769377fd25d1b3a827116577d0fcbdba486f7
all runs: boot failed: WARNING in kvm_mmu_set_mmio_spte_mask
revisions tested: 2, total time: 29m52.050805572s (build: 15m40.09935431s, test: 13m44.142858787s)
bisection is inconclusive, the first good commit could be any of:
01364dad1d4577e27a57729d41053f661bb8a5b9
4139fb08c05fec734f85a99e8b7d99dc12b1b68c