bisecting fixing commit since f6e27dbb1afabcba436e346d6aa88a592a1436bb building syzkaller on 2f1548bc77986e756b536eaa15726b483a0b1858 testing commit f6e27dbb1afabcba436e346d6aa88a592a1436bb with gcc (GCC) 8.1.0 kernel signature: 4e0c23a094500e3b4cafa6c2259b57333eb3729a959222963648e0fd6abd8c19 run #0: crashed: WARNING in check_for_bios_corruption run #1: crashed: WARNING in check_for_bios_corruption run #2: crashed: WARNING in check_for_bios_corruption run #3: crashed: WARNING in check_for_bios_corruption run #4: crashed: WARNING in check_for_bios_corruption run #5: crashed: WARNING in check_for_bios_corruption run #6: crashed: WARNING in check_for_bios_corruption run #7: crashed: WARNING in check_for_bios_corruption run #8: crashed: WARNING in check_for_bios_corruption run #9: boot failed: can't ssh into the instance testing current HEAD e0f8b8a65a473a8baa439cf865a694bbeb83fe90 testing commit e0f8b8a65a473a8baa439cf865a694bbeb83fe90 with gcc (GCC) 8.1.0 kernel signature: 597e0face41d82ad76095e0e179f0e743dbec4b0ab75c093955f6947d55a3ee0 all runs: crashed: WARNING in check_for_bios_corruption revisions tested: 2, total time: 39m53.872531894s (build: 16m55.239549574s, test: 22m35.510419802s) the crash still happens on HEAD commit msg: Linux 4.14.170 crash: WARNING in check_for_bios_corruption Corrupted low memory at ffff888000003fe8 (3fe8 phys) = ffffffffffffffff Corrupted low memory at ffff888000003ff0 (3ff0 phys) = ffffffffffffffff Corrupted low memory at ffff888000003ff8 (3ff8 phys) = ffffffffffffffff Memory corruption detected in low memory ------------[ cut here ]------------ WARNING: CPU: 0 PID: 7145 at arch/x86/kernel/check.c:157 check_for_bios_corruption.cold.2+0x13/0x1e arch/x86/kernel/check.c:157 Kernel panic - not syncing: panic_on_warn set ... CPU: 0 PID: 7145 Comm: kworker/0:4 Not tainted 4.14.170-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events check_corruption Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0xf7/0x13b lib/dump_stack.c:58 panic+0x1b0/0x358 kernel/panic.c:183 __warn.cold.8+0x25/0x2c kernel/panic.c:547 report_bug+0x1a4/0x1f3 lib/bug.c:186 fixup_bug arch/x86/kernel/traps.c:177 [inline] do_error_trap+0x1bd/0x310 arch/x86/kernel/traps.c:295 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:314 invalid_op+0x1b/0x40 arch/x86/entry/entry_64.S:963 RIP: 0010:check_for_bios_corruption.cold.2+0x13/0x1e arch/x86/kernel/check.c:157 RSP: 0018:ffff8880a07a7d10 EFLAGS: 00010282 RAX: 0000000000000028 RBX: ffff888000010000 RCX: 0000000000000000 RDX: 0000000000000028 RSI: ffffffff868cf180 RDI: ffffed10140f4f99 RBP: ffff8880a07a7d48 R08: ffff88808e7dcc88 R09: 0000000000000000 R10: 0000000000000000 R11: dffffc0000000000 R12: ffff888000010000 R13: dffffc0000000000 R14: 0000000000000001 R15: ffffffff887a55c0 check_corruption+0xd/0x63 arch/x86/kernel/check.c:165 process_one_work+0x79e/0x16c0 kernel/workqueue.c:2114 worker_thread+0xcc/0xee0 kernel/workqueue.c:2248 kthread+0x338/0x400 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Kernel Offset: disabled Rebooting in 86400 seconds..