general protection fault in __mmu_notifier_invalidate_range_start

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 1d177c08 Linux 4.14.224
git tree: linux-4.14.y
console output: https://syzkaller.appspot.com/x/log.txt?x=17cb54c2d00000
kernel config: https://syzkaller.appspot.com/x/.config?x=d474f9d9298a6d6a
dashboard link: https://syzkaller.appspot.com/bug?extid=d8d5d91ba58f60145d98

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

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+d8d5d9...@syzkaller.appspotmail.com

kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
Modules linked in:
CPU: 1 PID: 5 Comm: kworker/u4:0 Not tainted 4.14.224-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: writeback wb_workfn (flush-8:0)
task: ffff8880b5ff2140 task.stack: ffff8880b5ff8000
RIP: 0010:__read_once_size include/linux/compiler.h:183 [inline]
RIP: 0010:__mmu_notifier_invalidate_range_start+0x8e/0x190 mm/mmu_notifier.c:184
RSP: 0000:ffff8880b5fff088 EFLAGS: 00010206
RAX: dffffc0000000000 RBX: 0000000707000000 RCX: 14c0982608648300
RDX: 00000000e0e00000 RSI: 0000000000000001 RDI: ffff888000106b68
RBP: ffff888000106640 R08: 0000000000000000 R09: 0000000000020635
R10: ffff8880b5ff2a90 R11: ffff8880b5ff2140 R12: ffff888000106640
R13: 0000001b2f123000 R14: 0000001b2f124000 R15: 0000001b2f123000
FS: 0000000000000000(0000) GS:ffff8880ba500000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000970004 CR3: 00000000931b4000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
mmu_notifier_invalidate_range_start include/linux/mmu_notifier.h:263 [inline]
page_mkclean_one+0x471/0x540 mm/rmap.c:900
rmap_walk_file+0x37c/0x810 mm/rmap.c:1829
rmap_walk+0xc4/0x150 mm/rmap.c:1847
page_mkclean+0x148/0x180 mm/rmap.c:981
clear_page_dirty_for_io+0x1fa/0xa20 mm/page-writeback.c:2704
mpage_submit_page+0x6e/0x220 fs/ext4/inode.c:2215
mpage_process_page_bufs+0x425/0x520 fs/ext4/inode.c:2345
mpage_prepare_extent_to_map+0x43e/0xa10 fs/ext4/inode.c:2717
ext4_writepages+0xf88/0x32a0 fs/ext4/inode.c:2864
do_writepages+0xc3/0x240 mm/page-writeback.c:2361
__writeback_single_inode+0xda/0x1010 fs/fs-writeback.c:1377
writeback_sb_inodes+0x48b/0xd30 fs/fs-writeback.c:1639
__writeback_inodes_wb+0xbf/0x230 fs/fs-writeback.c:1708
wb_writeback+0x710/0xb80 fs/fs-writeback.c:1814
wb_check_background_flush fs/fs-writeback.c:1893 [inline]
wb_do_writeback fs/fs-writeback.c:1952 [inline]
wb_workfn+0x909/0xf50 fs/fs-writeback.c:1980
process_one_work+0x793/0x14a0 kernel/workqueue.c:2116
worker_thread+0x5cc/0xff0 kernel/workqueue.c:2250
kthread+0x30d/0x420 kernel/kthread.c:232
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404
Code: df 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 0a 01 00 00 49 8b 9c 24 28 05 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 da 48 c1 ea 03 <80> 3c 02 00 0f 85 da 00 00 00 48 8b 1b 48 85 db 74 79 e8 cb e5
RIP: __read_once_size include/linux/compiler.h:183 [inline] RSP: ffff8880b5fff088
RIP: __mmu_notifier_invalidate_range_start+0x8e/0x190 mm/mmu_notifier.c:184 RSP: ffff8880b5fff088
---[ end trace 82523de22ef27065 ]---


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[syzbot]

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