WARNING in folio_lruvec

WARNING in folio_lruvec_lock

Status: upstream: reported on 2025/06/19 12:02
Subsystems: cgroups mm
Labels: prio:high
[Documentation on labels]
Reported-by: syzbot+a74a028d848147bc5931@syzkaller.appspotmail.com
Fix commit: mm/vma: correctly invoke late KSM check after mmap hook
Patched on: [ci-upstream-linux-next-kasan-gce-root ci-upstream-rust-kasan-gce], missing on: [ci-qemu-gce-upstream-auto ci-qemu-native-arm64-kvm ci-qemu-upstream ci-qemu-upstream-386 ci-qemu2-arm32 ci-qemu2-arm64 ci-qemu2-arm64-compat ci-qemu2-arm64-mte ci-qemu2-riscv64 ci-snapshot-upstream-root ci-upstream-bpf-kasan-gce ci-upstream-bpf-next-kasan-gce ci-upstream-gce-arm64 ci-upstream-gce-leak ci-upstream-kasan-badwrites-root ci-upstream-kasan-gce ci-upstream-kasan-gce-386 ci-upstream-kasan-gce-root ci-upstream-kasan-gce-selinux-root ci-upstream-kasan-gce-smack-root ci-upstream-kmsan-gce-386-root ci-upstream-kmsan-gce-root ci-upstream-net-kasan-gce ci-upstream-net-this-kasan-gce ci2-upstream-fs ci2-upstream-kcsan-gce ci2-upstream-usb]
First crash: 365d, last: 365d

▶ ▼ ✨ AI Jobs (1)

ID	Workflow	Result	Correct	Bug	Created	Started	Finished	Revision	Error
c42c83b9-3362-41dc-88ce-3901306f1eb7	assessment-security	DenialOfService: ✅ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ✅ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ❌	❓	WARNING in folio_lruvec_lock	2026/05/26 13:06	2026/05/26 13:06	2026/05/26 14:06	c69befb30ac10e158cc9d1557b508ee3f0eca1de

▶ ▼ Discussions (2)

Title	Replies (including bot)	Last reply
Re: [PATCH v3 3/4] mm: prevent KSM from breaking VMA merging for new VMAs	3 (3)	2025/06/23 09:18
[syzbot] [cgroups?] [mm?] WARNING in folio_lruvec_lock	1 (2)	2025/06/20 11:50

Sample crash report:

 handle_mm_fault+0x740/0x8e0 mm/memory.c:6397
 faultin_page mm/gup.c:1186 [inline]
 __get_user_pages+0x1aef/0x30b0 mm/gup.c:1488
 populate_vma_page_range+0x29f/0x3a0 mm/gup.c:1922
 __mm_populate+0x24c/0x380 mm/gup.c:2025
 mm_populate include/linux/mm.h:3354 [inline]
 vm_mmap_pgoff+0x3f0/0x4c0 mm/util.c:584
 ksys_mmap_pgoff+0x587/0x760 mm/mmap.c:607
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
page_owner free stack trace missing
------------[ cut here ]------------
WARNING: CPU: 0 PID: 38 at ./include/linux/memcontrol.h:732 folio_lruvec include/linux/memcontrol.h:732 [inline]
WARNING: CPU: 0 PID: 38 at ./include/linux/memcontrol.h:732 folio_lruvec_lock+0x150/0x1a0 mm/memcontrol.c:1211
Modules linked in:
CPU: 0 UID: 0 PID: 38 Comm: ksmd Not tainted 6.16.0-rc1-next-20250613-syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:folio_lruvec include/linux/memcontrol.h:732 [inline]
RIP: 0010:folio_lruvec_lock+0x150/0x1a0 mm/memcontrol.c:1211
Code: 7c 25 00 00 74 08 4c 89 ff e8 7c 66 f8 ff 4d 89 2f eb c4 48 89 df 48 c7 c6 60 4f 98 8b e8 58 9b dc ff c6 05 01 85 5f 0d 01 90 <0f> 0b 90 e9 d5 fe ff ff 44 89 f9 80 e1 07 80 c1 03 38 c1 0f 8c 4d
RSP: 0018:ffffc90000ae7660 EFLAGS: 00010046
RAX: b21d845e3554e000 RBX: ffffea0002108000 RCX: b21d845e3554e000
RDX: 0000000000000002 RSI: ffffffff8db792e4 RDI: ffff88801de83c00
RBP: ffffea0002108000 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffffbfff1bfaa14 R12: ffffea0002108000
R13: ffffea0002108008 R14: 0000000000000000 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff888125c41000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f475c15ef98 CR3: 000000005f95a000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 __split_unmapped_folio+0x42e/0x2cb0 mm/huge_memory.c:3487
 __folio_split+0xf78/0x1300 mm/huge_memory.c:3891
 cmp_and_merge_page mm/ksm.c:2358 [inline]
 ksm_do_scan+0x499b/0x6530 mm/ksm.c:2665
 ksm_scan_thread+0x10b/0x4b0 mm/ksm.c:2687
 kthread+0x711/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Crashes (1):
Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro	VM info	Assets (help?)	Manager	Title
2025/06/15 11:56	linux-next	bc6e0ba6c9ba	5f4b362d	.config	console log	report			info	[disk image] [vmlinux] [kernel image]	ci-upstream-linux-next-kasan-gce-root	WARNING in folio_lruvec_lock

* ~~Struck through~~ repros no longer work on HEAD.