[syzbot] [mm?] kernel BUG in __free_one_page (2)

[syzbot <syzbot+43235b3002d58852ea38@syzkaller.appspotmail.com>]

Hello,

syzbot found the following issue on:

HEAD commit:    8736259279a3 Merge branch 'for-next/core' into for-kernelci
git tree:       git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci
console output: https://syzkaller.appspot.com/x/log.txt?x=1107e934580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=9ed0a6d7c80843e9
dashboard link: https://syzkaller.appspot.com/bug?extid=43235b3002d58852ea38
compiler:       Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
userspace arch: arm64
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=137f3362580000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=109f6b12580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/025c082a7762/disk-87362592.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/606f903fe4d2/vmlinux-87362592.xz
kernel image: https://storage.googleapis.com/syzbot-assets/23ea2634f398/Image-87362592.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+43235b3002d58852ea38@syzkaller.appspotmail.com

raw: 05ffc00000200000 fffffdffc3207008 ffff0001fea8cba0 0000000000000000
raw: 0000000000000000 0000000000000004 00000001f0000000 0000000000000000
page dumped because: VM_BUG_ON_PAGE(page_count(buddy) != 0)
------------[ cut here ]------------
kernel BUG at mm/internal.h:664!
Internal error: Oops - BUG: 00000000f2000800 [#1]  SMP
Modules linked in:
CPU: 0 UID: 0 PID: 6702 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/30/2025
pstate: 634000c5 (nZCv daIF +PAN -UAO +TCO +DIT -SSBS BTYPE=--)
pc : page_is_buddy mm/internal.h:664 [inline]
pc : find_buddy_page_pfn mm/internal.h:716 [inline]
pc : __free_one_page+0x8b8/0x988 mm/page_alloc.c:969
lr : page_is_buddy mm/internal.h:664 [inline]
lr : find_buddy_page_pfn mm/internal.h:716 [inline]
lr : __free_one_page+0x8b8/0x988 mm/page_alloc.c:969
sp : ffff8000a0ac71f0
x29: ffff8000a0ac7210 x28: fffffdffc3c88034 x27: fffffdffc3c88000
x26: 0000000000132200 x25: 0000000000000000 x24: 0000000000000004
x23: 0000000000132210 x22: dfff800000000000 x21: fffffdffc3c88400
x20: 0000000000000000 x19: ffff0001fea8c880 x18: 00000000ffffffff
x17: 3030303030303030 x16: ffff80008b0155d8 x15: 0000000000000001
x14: 1fffe000337976f2 x13: 0000000000000000 x12: 0000000000000000
x11: ffff6000337976f3 x10: 0000000000ff0100 x9 : e31af28274316600
x8 : e31af28274316600 x7 : ffff800080563530 x6 : 0000000000000000
x5 : 0000000000000001 x4 : 0000000000000000 x3 : ffff8000807de30c
x2 : 0000000000000001 x1 : 0000000100000001 x0 : 000000000000003b
Call trace:
 page_is_buddy mm/internal.h:664 [inline] (P)
 find_buddy_page_pfn mm/internal.h:716 [inline] (P)
 __free_one_page+0x8b8/0x988 mm/page_alloc.c:969 (P)
 split_large_buddy+0x108/0x1d0 mm/page_alloc.c:1512
 free_one_page+0x94/0x2e0 mm/page_alloc.c:1559
 free_unref_folios+0x6b0/0x1454 mm/page_alloc.c:2959
 folios_put_refs+0x608/0x718 mm/swap.c:997
 folios_put include/linux/mm.h:1419 [inline]
 __folio_batch_release+0x78/0xb0 mm/swap.c:1057
 folio_batch_release include/linux/pagevec.h:101 [inline]
 truncate_inode_pages_range+0x2f8/0xe18 mm/truncate.c:383
 truncate_inode_pages+0x2c/0x3c mm/truncate.c:460
 kill_bdev block/bdev.c:91 [inline]
 blkdev_flush_mapping+0xfc/0x254 block/bdev.c:712
 blkdev_put_whole block/bdev.c:719 [inline]
 bdev_release+0x478/0x654 block/bdev.c:1144
 blkdev_release+0x20/0x34 block/fops.c:699
 __fput+0x340/0x75c fs/file_table.c:468
 ____fput+0x20/0x58 fs/file_table.c:496
 task_work_run+0x1dc/0x260 kernel/task_work.c:227
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0x524/0x1a14 kernel/exit.c:961
 do_group_exit+0x194/0x22c kernel/exit.c:1102
 __do_sys_exit_group kernel/exit.c:1113 [inline]
 __se_sys_exit_group kernel/exit.c:1111 [inline]
 pid_child_should_wake+0x0/0x1dc kernel/exit.c:1111
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
 el0_svc+0x5c/0x254 arch/arm64/kernel/entry-common.c:744
 el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:763
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596
Code: 90052f41 913e0021 aa1b03e0 97d585d0 (d4210000) 
---[ end trace 0000000000000000 ]---


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.

If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)

If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup