[syzbot] [bcachefs?] WARNING in srcu_check_nmi_safety

From: syzbot <syzbot+62be362ff074b84ca393@syzkaller.appspotmail.com>
To: kent.overstreet@linux.dev, kvm@vger.kernel.org,
	 linux-bcachefs@vger.kernel.org, linux-fsdevel@vger.kernel.org,
	 linux-kernel@vger.kernel.org, pbonzini@redhat.com,
	 syzkaller-bugs@googlegroups.com
Subject: [syzbot] [bcachefs?] WARNING in srcu_check_nmi_safety
Date: Sat, 04 May 2024 03:09:23 -0700	[thread overview]
Message-ID: <000000000000d258a006179e07df@google.com> (raw)

Hello,

syzbot found the following issue on:

HEAD commit:    3d25a941ea50 Merge tag 'block-6.9-20240503' of git://git.k..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1143ae60980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=45d8db3acdc1ccc6
dashboard link: https://syzkaller.appspot.com/bug?extid=62be362ff074b84ca393
compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: i386

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

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7bc7510fe41f/non_bootable_disk-3d25a941.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/49d9f26b0beb/vmlinux-3d25a941.xz
kernel image: https://storage.googleapis.com/syzbot-assets/d2c424c14fff/bzImage-3d25a941.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+62be362ff074b84ca393@syzkaller.appspotmail.com

------------[ cut here ]------------
CPU 0 old state 2 new state 1
WARNING: CPU: 0 PID: 110 at kernel/rcu/srcutree.c:702 srcu_check_nmi_safety+0x10e/0x130 kernel/rcu/srcutree.c:702
Modules linked in:
CPU: 0 PID: 110 Comm: kswapd0 Not tainted 6.9.0-rc6-syzkaller-00227-g3d25a941ea50 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:srcu_check_nmi_safety+0x10e/0x130 kernel/rcu/srcutree.c:702
Code: c0 74 11 3c 03 7f 0d 89 54 24 04 e8 8c 9e 76 00 8b 54 24 04 8b b3 c8 01 00 00 44 89 e1 48 c7 c7 e0 40 0e 8b e8 23 c4 dc ff 90 <0f> 0b 90 90 e9 7b ff ff ff e8 64 9e 76 00 e9 65 ff ff ff e8 8a 9e
RSP: 0018:ffffc90000e4ee00 EFLAGS: 00010282
RAX: 0000000000000000 RBX: ffffe8ffad288000 RCX: ffffffff815139f9
RDX: ffff888019e54880 RSI: ffffffff81513a06 RDI: 0000000000000001
RBP: ffffc9000334a890 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000005 R12: 0000000000000001
R13: ffff888014c79c80 R14: ffffc9000334a890 R15: ffffc9000334a810
FS:  0000000000000000(0000) GS:ffff88802c200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000f73ac1bc CR3: 000000004dd50000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 srcu_read_lock include/linux/srcu.h:213 [inline]
 __kvm_handle_hva_range arch/x86/kvm/../../../virt/kvm/kvm_main.c:614 [inline]
 kvm_handle_hva_range arch/x86/kvm/../../../virt/kvm/kvm_main.c:687 [inline]
 kvm_mmu_notifier_clear_flush_young+0x12f/0x700 arch/x86/kvm/../../../virt/kvm/kvm_main.c:912
 __mmu_notifier_clear_flush_young+0x110/0x1e0 mm/mmu_notifier.c:377
 mmu_notifier_clear_flush_young include/linux/mmu_notifier.h:421 [inline]
 folio_referenced_one+0x5d2/0xf60 mm/rmap.c:881
 rmap_walk_anon+0x226/0x580 mm/rmap.c:2599
 rmap_walk mm/rmap.c:2676 [inline]
 rmap_walk mm/rmap.c:2671 [inline]
 folio_referenced+0x288/0x4b0 mm/rmap.c:990
 folio_check_references mm/vmscan.c:835 [inline]
 shrink_folio_list+0x1a8a/0x3f00 mm/vmscan.c:1168
 evict_folios+0x6e6/0x1bb0 mm/vmscan.c:4537
 try_to_shrink_lruvec+0x618/0x9b0 mm/vmscan.c:4733
 shrink_one+0x3f8/0x7c0 mm/vmscan.c:4772
 shrink_many mm/vmscan.c:4835 [inline]
 lru_gen_shrink_node+0x89f/0x1750 mm/vmscan.c:4935
 shrink_node mm/vmscan.c:5894 [inline]
 kswapd_shrink_node mm/vmscan.c:6704 [inline]
 balance_pgdat+0x10d1/0x1a10 mm/vmscan.c:6895
 kswapd+0x5ea/0xbf0 mm/vmscan.c:7164
 kthread+0x2c1/0x3a0 kernel/kthread.c:388
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

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