WARNING in check_for_bios_corruption

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: f6e27dbb Linux 4.14.146
git tree: linux-4.14.y
console output: https://syzkaller.appspot.com/x/log.txt?x=129d736d600000
kernel config: https://syzkaller.appspot.com/x/.config?x=cb75afefe94a0801
dashboard link: https://syzkaller.appspot.com/bug?extid=73619b5f1dde39f429cb
compiler: gcc (GCC) 9.0.0 20181231 (experimental)

Unfortunately, I don't have any reproducer for this crash yet.

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+73619b...@syzkaller.appspotmail.com

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: 7048 at arch/x86/kernel/check.c:157
check_for_bios_corruption arch/x86/kernel/check.c:157 [inline]
WARNING: CPU: 0 PID: 7048 at arch/x86/kernel/check.c:157
check_for_bios_corruption.cold+0x13/0x26 arch/x86/kernel/check.c:135
Kernel panic - not syncing: panic_on_warn set ...

CPU: 0 PID: 7048 Comm: kworker/0:2 Not tainted 4.14.146 #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+0x138/0x197 lib/dump_stack.c:53
panic+0x1f2/0x426 kernel/panic.c:182
__warn.cold+0x2f/0x36 kernel/panic.c:546
report_bug+0x216/0x254 lib/bug.c:186
fixup_bug arch/x86/kernel/traps.c:177 [inline]
fixup_bug arch/x86/kernel/traps.c:172 [inline]
do_error_trap+0x1bb/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 arch/x86/kernel/check.c:157 [inline]
RIP: 0010:check_for_bios_corruption.cold+0x13/0x26
arch/x86/kernel/check.c:135
RSP: 0018:ffff88806214fce8 EFLAGS: 00010282
RAX: 0000000000000028 RBX: ffff888000010000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffff888062140d28 RDI: ffffed100c429f93
RBP: ffff88806214fd20 R08: 0000000000000028 R09: ffff888062140d48
R10: 0000000000000000 R11: 0000000000000000 R12: ffff888000010000
R13: dffffc0000000000 R14: 0000000000000001 R15: ffff888000000000
check_corruption+0xd/0x67 arch/x86/kernel/check.c:165
process_one_work+0x863/0x1600 kernel/workqueue.c:2114
worker_thread+0x5d9/0x1050 kernel/workqueue.c:2248
kthread+0x319/0x430 kernel/kthread.c:232
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404
Kernel Offset: disabled
Rebooting in 86400 seconds..


---
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[syzbot]

syzbot has found a reproducer for the following crash on:

HEAD commit: f6e27dbb Linux 4.14.146
git tree: linux-4.14.y

console output: https://syzkaller.appspot.com/x/log.txt?x=14925aa9600000

kernel config: https://syzkaller.appspot.com/x/.config?x=cb75afefe94a0801
dashboard link: https://syzkaller.appspot.com/bug?extid=73619b5f1dde39f429cb
compiler: gcc (GCC) 9.0.0 20181231 (experimental)

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=106b38cb600000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=144e139d600000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+73619b...@syzkaller.appspotmail.com

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: 24 at arch/x86/kernel/check.c:157
check_for_bios_corruption arch/x86/kernel/check.c:157 [inline]
WARNING: CPU: 0 PID: 24 at arch/x86/kernel/check.c:157

check_for_bios_corruption.cold+0x13/0x26 arch/x86/kernel/check.c:135
Kernel panic - not syncing: panic_on_warn set ...

CPU: 0 PID: 24 Comm: kworker/0:1 Not tainted 4.14.146 #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+0x138/0x197 lib/dump_stack.c:53
panic+0x1f2/0x426 kernel/panic.c:182
__warn.cold+0x2f/0x36 kernel/panic.c:546
report_bug+0x216/0x254 lib/bug.c:186
fixup_bug arch/x86/kernel/traps.c:177 [inline]
fixup_bug arch/x86/kernel/traps.c:172 [inline]
do_error_trap+0x1bb/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 arch/x86/kernel/check.c:157 [inline]
RIP: 0010:check_for_bios_corruption.cold+0x13/0x26
arch/x86/kernel/check.c:135

RSP: 0018:ffff8880a9e67ce8 EFLAGS: 00010282

RAX: 0000000000000028 RBX: ffff888000010000 RCX: 0000000000000000

RDX: 0000000000000000 RSI: ffffffff866d10e0 RDI: ffffed10153ccf93
RBP: ffff8880a9e67d20 R08: 0000000000000028 R09: ffff8880a9e58f08