bisecting fixing commit since dafd634415a7f9892a6fcc99c540fe567ab42c92 building syzkaller on 2f661ec405cb3975128e9851c7a5979d92d001f1 testing commit dafd634415a7f9892a6fcc99c540fe567ab42c92 with gcc (GCC) 8.4.1 20210217 kernel signature: a87c31af49afe0b34038a75c44ccbb6b04f1bb05d64d48e99a5451e07ea52837 all runs: crashed: WARNING in check_for_bios_corruption testing current HEAD eb575cd5d7f60241d016fdd13a9e86d962093c9b testing commit eb575cd5d7f60241d016fdd13a9e86d962093c9b with gcc (GCC) 8.4.1 20210217 kernel signature: 2ebc315e5f809d2c71b60873b691b9ac13cb945bf8f8699df4010ff6f05b7038 all runs: crashed: WARNING in check_for_bios_corruption revisions tested: 2, total time: 27m10.380055217s (build: 19m27.83763983s, test: 6m56.998834967s) the crash still happens on HEAD commit msg: Linux 4.19.195 crash: WARNING in check_for_bios_corruption Corrupted low memory at 000000007ebe76ca (2900 phys) = 000000e8 ------------[ cut here ]------------ Memory corruption detected in low memory WARNING: CPU: 0 PID: 14 at arch/x86/kernel/check.c:157 check_for_bios_corruption arch/x86/kernel/check.c:157 [inline] WARNING: CPU: 0 PID: 14 at arch/x86/kernel/check.c:157 check_for_bios_corruption+0x10c/0x1d0 arch/x86/kernel/check.c:135 Modules linked in: CPU: 0 PID: 14 Comm: kworker/0:1 Not tainted 4.19.195-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events check_corruption RIP: 0010:check_for_bios_corruption arch/x86/kernel/check.c:157 [inline] RIP: 0010:check_for_bios_corruption+0x10c/0x1d0 arch/x86/kernel/check.c:135 Code: c4 10 5b 41 5c 41 5d 41 5e 41 5f 5d c3 c3 80 3d 38 89 a4 07 00 75 e7 48 c7 c7 e0 58 e7 86 c6 05 28 89 a4 07 01 e8 75 b7 48 05 <0f> 0b eb d0 48 89 df 89 55 d0 e8 e5 5f 66 00 8b 55 d0 49 b8 00 00 RSP: 0018:ffff8881f5707d08 EFLAGS: 00010286 RAX: 0000000000000000 RBX: ffff888000010000 RCX: 0000000000000000 RDX: 0000000000000004 RSI: ffffffff871f62e0 RDI: ffffffff89c8c6e0 RBP: ffff8881f5707d40 R08: ffffed103ed05079 R09: ffffed103ed05078 R10: ffffed103ed05078 R11: ffff8881f68283c7 R12: ffff888000010000 R13: dffffc0000000000 R14: 0000000000000001 R15: ffffffff890ae0a0 FS: 0000000000000000(0000) GS:ffff8881f6800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffca3a99e98 CR3: 000000000806d006 CR4: 00000000001606f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: check_corruption+0xd/0x70 arch/x86/kernel/check.c:165 process_one_work+0x830/0x1670 kernel/workqueue.c:2153 worker_thread+0x85/0xb60 kernel/workqueue.c:2296 kthread+0x347/0x410 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 irq event stamp: 557900 hardirqs last enabled at (557899): [] __free_pages_ok+0x630/0xd80 mm/page_alloc.c:1286 hardirqs last disabled at (557900): [] trace_hardirqs_off_thunk+0x1a/0x1c softirqs last enabled at (557860): [] __do_softirq+0x62d/0x919 kernel/softirq.c:318 softirqs last disabled at (557853): [] invoke_softirq kernel/softirq.c:372 [inline] softirqs last disabled at (557853): [] irq_exit+0x17f/0x1c0 kernel/softirq.c:412 ---[ end trace 6fee598a8362ac8d ]---