BUG: unable to handle kernel paging request in clear_page_erms

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: a811c1fa Merge git://git.kernel.org/pub/scm/linux/kernel/g..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=11deb588100000
kernel config: https://syzkaller.appspot.com/x/.config?x=b0212dbee046bc1f
dashboard link: https://syzkaller.appspot.com/bug?extid=a991ddcd1fc86f6fdfdb
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
CC: [ak...@linux-foundation.org linux-...@vger.kernel.org linu...@kvack.org]

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+a991dd...@syzkaller.appspotmail.com

BUG: unable to handle page fault for address: ffff8882108cb000
#PF: supervisor write access in kernel mode
#PF: error_code(0x0002) - not-present page
PGD d401067 P4D d401067 PUD d404067 PMD 16a063 PTE 0
Oops: 0002 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 7584 Comm: syz-executor.4 Not tainted 5.7.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:clear_page_erms+0x7/0x10 arch/x86/lib/clear_page_64.S:49
Code: 48 89 47 18 48 89 47 20 48 89 47 28 48 89 47 30 48 89 47 38 48 8d 7f 40 75 d9 90 c3 0f 1f 80 00 00 00 00 b9 00 10 00 00 31 c0 <f3> aa c3 cc cc cc cc cc cc 41 57 41 56 41 55 41 54 55 53 48 89 fb
RSP: 0018:ffffc90005397498 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffffea00084232c0 RCX: 0000000000001000
RDX: 1ffff1100c7b9306 RSI: 0000000000000001 RDI: ffff8882108cb000
RBP: ffff888063dc8580 R08: ffff888063dc8580 R09: ffffed1042119600
R10: ffffea00084232f7 R11: fffff9400108465e R12: ffffed100c7b9338
R13: dffffc0000000000 R14: ffffea0008423300 R15: ffff888063dc99c0
FS: 0000000002037940(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffff8882108cb000 CR3: 0000000063cda000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
clear_page arch/x86/include/asm/page_64.h:49 [inline]
clear_highpage include/linux/highmem.h:214 [inline]
kernel_init_free_pages+0x92/0x120 mm/page_alloc.c:1170
prep_new_page+0x12e/0x1f0 mm/page_alloc.c:2210
get_page_from_freelist+0x1538/0x3580 mm/page_alloc.c:3753
__alloc_pages_nodemask+0x29f/0x810 mm/page_alloc.c:4803
alloc_pages_current+0xff/0x200 mm/mempolicy.c:2295
alloc_pages include/linux/gfp.h:540 [inline]
__pte_alloc_one include/asm-generic/pgalloc.h:63 [inline]
pte_alloc_one+0x16/0x190 arch/x86/mm/pgtable.c:26
__pte_alloc+0x1b/0x310 mm/memory.c:426
copy_pte_range mm/memory.c:828 [inline]
copy_pmd_range mm/memory.c:904 [inline]
copy_pud_range mm/memory.c:938 [inline]
copy_p4d_range mm/memory.c:960 [inline]
copy_page_range+0x14fc/0x1f00 mm/memory.c:1022
dup_mmap kernel/fork.c:607 [inline]
dup_mm+0x9a4/0x1300 kernel/fork.c:1363
copy_mm kernel/fork.c:1419 [inline]
copy_process+0x29cc/0x7110 kernel/fork.c:2085
_do_fork+0x12d/0x1010 kernel/fork.c:2430
__do_sys_clone+0xec/0x140 kernel/fork.c:2585
do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295
entry_SYSCALL_64_after_hwframe+0x49/0xb3
RIP: 0033:0x45ae5a
Code: f7 d8 64 89 04 25 d4 02 00 00 64 4c 8b 0c 25 10 00 00 00 31 d2 4d 8d 91 d0 02 00 00 31 f6 bf 11 00 20 01 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 0f 87 f5 00 00 00 85 c0 41 89 c5 0f 85 fc 00 00
RSP: 002b:0000000000c9fd60 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 0000000000c9fd60 RCX: 000000000045ae5a
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 0000000000c9fda0 R08: 0000000000000001 R09: 0000000002037940
R10: 0000000002037c10 R11: 0000000000000246 R12: 0000000000000001
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000c9fdf0
Modules linked in:
CR2: ffff8882108cb000
---[ end trace 096d730dce876262 ]---
RIP: 0010:clear_page_erms+0x7/0x10 arch/x86/lib/clear_page_64.S:49
Code: 48 89 47 18 48 89 47 20 48 89 47 28 48 89 47 30 48 89 47 38 48 8d 7f 40 75 d9 90 c3 0f 1f 80 00 00 00 00 b9 00 10 00 00 31 c0 <f3> aa c3 cc cc cc cc cc cc 41 57 41 56 41 55 41 54 55 53 48 89 fb
RSP: 0018:ffffc90005397498 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffffea00084232c0 RCX: 0000000000001000
RDX: 1ffff1100c7b9306 RSI: 0000000000000001 RDI: ffff8882108cb000
RBP: ffff888063dc8580 R08: ffff888063dc8580 R09: ffffed1042119600
R10: ffffea00084232f7 R11: fffff9400108465e R12: ffffed100c7b9338
R13: dffffc0000000000 R14: ffffea0008423300 R15: ffff888063dc99c0
FS: 0000000002037940(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffff8882108cb000 CR3: 0000000063cda000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.