bisecting fixing commit since dafd634415a7f9892a6fcc99c540fe567ab42c92
building syzkaller on 2f661ec405cb3975128e9851c7a5979d92d001f1
testing commit dafd634415a7f9892a6fcc99c540fe567ab42c92 with gcc (GCC) 8.1.0
kernel signature: 8e112ac7013389e6271065009f3ebe12cca62331e4e220e8cfc2e9097f82d73c
all runs: crashed: WARNING in check_for_bios_corruption
testing current HEAD c37da90efff5f183bea6ae4c2af33571f61fe317
testing commit c37da90efff5f183bea6ae4c2af33571f61fe317 with gcc (GCC) 8.1.0
kernel signature: 87114c6364482cefef357d75b9c2719275d71c4910dc58d90dd8066a179e50f4
all runs: crashed: WARNING in check_for_bios_corruption
revisions tested: 2, total time: 29m23.660351763s (build: 20m59.175080941s, test: 6m35.214719571s)
the crash still happens on HEAD
commit msg: Linux 4.19.143
crash: WARNING in check_for_bios_corruption
Corrupted low memory at 000000007680bc8b (2900 phys) = 000000e8
------------[ cut here ]------------
Memory corruption detected in low memory
WARNING: CPU: 0 PID: 3310 at arch/x86/kernel/check.c:157 check_for_bios_corruption+0x10c/0x1d0 arch/x86/kernel/check.c:157
Kernel panic - not syncing: panic_on_warn set ...

CPU: 0 PID: 3310 Comm: kworker/0:3 Not tainted 4.19.143-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:77 [inline]
 dump_stack+0x123/0x177 lib/dump_stack.c:118
 panic+0x1cd/0x375 kernel/panic.c:186
 __warn.cold.8+0x1b/0x3e kernel/panic.c:541
 report_bug+0x1a4/0x200 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:178 [inline]
 do_error_trap+0x200/0x350 arch/x86/kernel/traps.c:296
 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:316
 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:1038
RIP: 0010:check_for_bios_corruption+0x10c/0x1d0 arch/x86/kernel/check.c:157
Code: c4 10 5b 41 5c 41 5d 41 5e 41 5f 5d c3 c3 80 3d 6b a1 a3 07 00 75 e7 48 c7 c7 60 63 e7 86 c6 05 5b a1 a3 07 01 e8 d7 73 0f 00 <0f> 0b eb d0 48 89 df 89 55 d0 e8 65 c2 67 00 8b 55 d0 49 b8 00 00
RSP: 0018:ffff88809b907d08 EFLAGS: 00010286
RAX: 0000000000000000 RBX: ffff888000010000 RCX: 0000000000000000
RDX: 0000000000000004 RSI: ffffffff871f4840 RDI: ffffffff89c936a0
RBP: ffff88809b907d40 R08: ffffed1015d45079 R09: ffffed1015d45078
R10: ffffed1015d45078 R11: ffff8880aea283c7 R12: ffff888000010000
R13: dffffc0000000000 R14: 0000000000000001 R15: ffffffff890b50a0
 check_corruption+0xd/0x63 arch/x86/kernel/check.c:165
 process_one_work+0x830/0x1670 kernel/workqueue.c:2155
 worker_thread+0x85/0xb60 kernel/workqueue.c:2298
 kthread+0x347/0x410 kernel/kthread.c:259
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415
Kernel Offset: disabled
Rebooting in 86400 seconds..