[v6.1] WARNING in page_counter_uncharge

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: f6e38ae624cf Linux 6.1.158
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=175f98c2580000
kernel config: https://syzkaller.appspot.com/x/.config?x=7eb38bd5021fec61
dashboard link: https://syzkaller.appspot.com/bug?extid=7467a8c2e83fa36ad128
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/2b7003e2661d/disk-f6e38ae6.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/0696cea8d016/vmlinux-f6e38ae6.xz
kernel image: https://storage.googleapis.com/syzbot-assets/6b7a89e636d7/bzImage-f6e38ae6.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+7467a8...@syzkaller.appspotmail.com

------------[ cut here ]------------
page_counter underflow: -1024 nr_pages=1024
WARNING: CPU: 0 PID: 4607 at mm/page_counter.c:56 page_counter_cancel mm/page_counter.c:55 [inline]
WARNING: CPU: 0 PID: 4607 at mm/page_counter.c:56 page_counter_uncharge+0xee/0x110 mm/page_counter.c:158
Modules linked in:
CPU: 0 PID: 4607 Comm: syz.4.45 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:page_counter_cancel mm/page_counter.c:55 [inline]
RIP: 0010:page_counter_uncharge+0xee/0x110 mm/page_counter.c:158
Code: 74 2f e8 05 ad a9 ff e9 5d ff ff ff e8 fb ac a9 ff c6 05 aa dc 33 0c 01 48 c7 c7 40 4a 98 8a 4c 89 fe 48 89 da e8 c2 d1 75 ff <0f> 0b e9 74 ff ff ff e8 d6 ac a9 ff eb 05 e8 cf ac a9 ff 5b 41 5c
RSP: 0018:ffffc900053af9c0 EFLAGS: 00010246
RAX: fc6245c8cf4d8d00 RBX: 0000000000000400 RCX: ffff88807a661dc0
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000002
RBP: ffff888056998520 R08: dffffc0000000000 R09: fffff52000a75ec9
R10: fffff52000a75ec9 R11: 1ffff92000a75ec8 R12: dffffc0000000000
R13: fffffffffffffc00 R14: ffff88807dfc7380 R15: fffffffffffffc00
FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f804b96b000 CR3: 000000005cb85000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
hugetlb_cgroup_uncharge_counter+0xc3/0x120 mm/hugetlb_cgroup.c:430
hugetlb_vm_op_close+0x550/0x930 mm/hugetlb.c:4889
vma_close+0x6b/0xa0 mm/util.c:1129
remove_vma mm/mmap.c:140 [inline]
exit_mmap+0x3e8/0x8e0 mm/mmap.c:3272
__mmput+0x118/0x3c0 kernel/fork.c:1200
exit_mm+0x1e6/0x2c0 kernel/exit.c:565
do_exit+0x8c1/0x2400 kernel/exit.c:867
do_group_exit+0x217/0x2d0 kernel/exit.c:1022
__do_sys_exit_group kernel/exit.c:1033 [inline]
__se_sys_exit_group kernel/exit.c:1031 [inline]
__x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1031
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f7e48f8f749
Code: Unable to access opcode bytes at 0x7f7e48f8f71f.
RSP: 002b:00007fffbdb26428 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f7e48f8f749
RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fffbdb2648c R08: 00000005bdb2651f R09: 00000000000927c0
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000009
R13: 00000000000927c0 R14: 0000000000012a40 R15: 00007fffbdb264e0
</TASK>


---
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[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: f6e38ae624cf Linux 6.1.158
git tree: linux-6.1.y

console output: https://syzkaller.appspot.com/x/log.txt?x=15d2c192580000

kernel config: https://syzkaller.appspot.com/x/.config?x=7eb38bd5021fec61
dashboard link: https://syzkaller.appspot.com/bug?extid=7467a8c2e83fa36ad128
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=155058c2580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1739f912580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/2b7003e2661d/disk-f6e38ae6.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/0696cea8d016/vmlinux-f6e38ae6.xz
kernel image: https://storage.googleapis.com/syzbot-assets/6b7a89e636d7/bzImage-f6e38ae6.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+7467a8...@syzkaller.appspotmail.com

R10: 0000000000000003 R11: 0000000000000246 R12: 0000000000000002
R13: 00007f52fb5e5fa0 R14: 00007f52fb5e5fa0 R15: 0000000000000005
</TASK>

------------[ cut here ]------------
page_counter underflow: -1024 nr_pages=1024

WARNING: CPU: 1 PID: 4437 at mm/page_counter.c:56 page_counter_cancel mm/page_counter.c:55 [inline]
WARNING: CPU: 1 PID: 4437 at mm/page_counter.c:56 page_counter_uncharge+0xee/0x110 mm/page_counter.c:158
Modules linked in:
CPU: 1 PID: 4437 Comm: syz.0.22 Not tainted syzkaller #0

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:page_counter_cancel mm/page_counter.c:55 [inline]
RIP: 0010:page_counter_uncharge+0xee/0x110 mm/page_counter.c:158
Code: 74 2f e8 05 ad a9 ff e9 5d ff ff ff e8 fb ac a9 ff c6 05 aa dc 33 0c 01 48 c7 c7 40 4a 98 8a 4c 89 fe 48 89 da e8 c2 d1 75 ff <0f> 0b e9 74 ff ff ff e8 d6 ac a9 ff eb 05 e8 cf ac a9 ff 5b 41 5c

RSP: 0018:ffffc900040c79c0 EFLAGS: 00010246
RAX: 8a20ac9aeb7b4e00 RBX: 0000000000000400 RCX: ffff88801a7ed940

RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000002

RBP: ffff88805c481d20 R08: dffffc0000000000 R09: fffff52000818ec9
R10: fffff52000818ec9 R11: 1ffff92000818ec8 R12: dffffc0000000000
R13: fffffffffffffc00 R14: ffff88807df50380 R15: fffffffffffffc00
FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000

CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033

CR2: 000000c008318000 CR3: 000000007e23d000 CR4: 00000000003506e0

DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
hugetlb_cgroup_uncharge_counter+0xc3/0x120 mm/hugetlb_cgroup.c:430
hugetlb_vm_op_close+0x550/0x930 mm/hugetlb.c:4889
vma_close+0x6b/0xa0 mm/util.c:1129
remove_vma mm/mmap.c:140 [inline]
exit_mmap+0x3e8/0x8e0 mm/mmap.c:3272
__mmput+0x118/0x3c0 kernel/fork.c:1200
exit_mm+0x1e6/0x2c0 kernel/exit.c:565
do_exit+0x8c1/0x2400 kernel/exit.c:867
do_group_exit+0x217/0x2d0 kernel/exit.c:1022
__do_sys_exit_group kernel/exit.c:1033 [inline]
__se_sys_exit_group kernel/exit.c:1031 [inline]
__x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1031
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2

RIP: 0033:0x7f52fb38f749
Code: Unable to access opcode bytes at 0x7f52fb38f71f.
RSP: 002b:00007ffeb9417498 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f52fb38f749

RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000

RBP: 00007ffeb94174fc R08: 00000002b941758f R09: 00000000000927c0
R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000005
R13: 00000000000927c0 R14: 00000000000175c3 R15: 00007ffeb9417550
</TASK>


---
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