WARNING in memory_failure() at include/linux/huge_mm.h:635 triggered

[是参差 <shicenci@gmail.com>]

Hi,
I’m reporting a reproducible WARNING triggered in the hwpoison / memory_failure path when injecting a hardware-poison event via madvise(MADV_HWPOISON).

The warning is triggered by a syzkaller C reproducer that:
maps a file-backed region with MAP_FIXED, touches related VMAs, and then
calls madvise() with MADV_HWPOISON over a large range.
The kernel reports a VM_WARN_ON_ONCE_FOLIO(1) from memory_failure() and points to include/linux/huge_mm.h:635, suggesting an unexpected folio/page state encountered while handling a poisoned compound/huge folio.

The target page appears to be a compound head page (order:3) already marked hwpoison. memory_failure() seems to reach a branch that unconditionally warns (VM_WARN_ON_ONCE_FOLIO(1) at include/linux/huge_mm.h:635), which usually indicates an “unreachable”/unexpected folio type or state transition in the huge/compound folio handling logic during hwpoison processing.

This looks like a kernel-side invariant violation rather than a pure userspace misuse, since the warning is emitted from an unconditional VM_WARN_ON_ONCE_FOLIO(1) site.

Reproducer:
C reproducer: https://pastebin.com/raw/UxennX2B
console output: https://pastebin.com/raw/wrhKRwZY
kernel config: https://pastebin.com/raw/dP93yBLn

Kernel:

HEAD commit: 63804fed149a6750ffd28610c5c1c98cce6bd377

 git tree: torvalds/linux 

kernel version: 6.19.0-rc7  (QEMU Ubuntu 24.10)


head: 0000000000000003 ffffea00003f8a01 0000000800000007 00000000ffffffff
head: ffff88800fe29e00 0000000000000000 0000000000000000 0000000000000008
page dumped because: VM_WARN_ON_ONCE_FOLIO(1)
------------[ cut here ]------------
WARNING: include/linux/huge_mm.h:635 at min_order_for_split include/linux/huge_mm.h:635 [inline], CPU#0: syz.3.7564/25556
WARNING: include/linux/huge_mm.h:635 at min_order_for_split include/linux/huge_mm.h:633 [inline], CPU#0: syz.3.7564/25556
WARNING: include/linux/huge_mm.h:635 at memory_failure+0x22e8/0x2950 mm/memory-failure.c:2434, CPU#0: syz.3.7564/25556
CPU: 0 UID: 0 PID: 25556 Comm: syz.3.7564 Not tainted 6.19.0-rc7 #1 VOLUNTARY 
Hardware name: QEMU Ubuntu 24.10 PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:min_order_for_split include/linux/huge_mm.h:635 [inline]
RIP: 0010:min_order_for_split include/linux/huge_mm.h:633 [inline]
RIP: 0010:memory_failure+0x22e8/0x2950 mm/memory-failure.c:2434
Code: ff 84 db 0f 85 f1 f5 ff ff e9 36 fe ff ff e8 3f 55 ce ff 48 c7 c6 e0 f7 ee 85 4c 89 f7 e8 90 b6 ed ff c6 05 13 35 04 06 01 90 <0f> 0b 90 e9 aa ee ff ff e8 eb 15 fe ff e9 65 e1 ff ff e8 a1 15 fe
RSP: 0018:ffff888000b7fa00 EFLAGS: 00010216
RAX: 00000000000066f1 RBX: 0000000000000000 RCX: ffffc90004fbb000
RDX: 0000000000080000 RSI: ffff888029a3c500 RDI: 0000000000000002
RBP: ffffea00003f8a00 R08: fffffbfff0ddc501 R09: ffffffff819105e0
R10: 0000000000000001 R11: ffff888000b7f7e7 R12: 000000000000fe28
R13: ffffea00003f8a00 R14: ffffea00003f8a00 R15: ffffea00003f8a08
FS:  00007f3d36d7f6c0(0000) GS:0000000000000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3d384a3828 CR3: 00000000589a9000 CR4: 0000000000350ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <TASK>
 madvise_inject_error mm/madvise.c:1489 [inline]
 madvise_do_behavior.part.0+0x137/0x3c0 mm/madvise.c:1927
 madvise_do_behavior+0x41d/0x5d0 mm/madvise.c:979
 do_madvise+0x134/0x1b0 mm/madvise.c:2030
 __do_sys_madvise mm/madvise.c:2039 [inline]
 __se_sys_madvise mm/madvise.c:2037 [inline]
 __x64_sys_madvise+0xa8/0x110 mm/madvise.c:2037
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xa9/0x320 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x4b/0x53
RIP: 0033:0x7f3d3831ebe9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f3d36d7f038 EFLAGS: 00000246 ORIG_RAX: 000000000000001c
RAX: ffffffffffffffda RBX: 00007f3d38555fa0 RCX: 00007f3d3831ebe9
RDX: 0000000000000064 RSI: 0000000000600000 RDI: 0000200000000000
RBP: 00007f3d383a1e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f3d38556038 R14: 00007f3d38555fa0 R15: 00007ffe8f52e9d8
 </TASK>
---[ end trace 0000000000000000 ]---