[syzbot] [f2fs?] general protection fault in f2fs_in_warm_node_list

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 2961f841b025 Merge tag 'turbostat-2026.02.14' of git://git..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=12c5db3a580000
kernel config: https://syzkaller.appspot.com/x/.config?x=65722f41f7edc17e
dashboard link: https://syzkaller.appspot.com/bug?extid=6e4cb1cac5efc96ea0ca
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=17ac695a580000

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-2961f841.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/19ffd1a88c42/vmlinux-2961f841.xz
kernel image: https://storage.googleapis.com/syzbot-assets/621dc0fadd96/bzImage-2961f841.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/7ce23d543372/mount_5.gz
fsck result: failed (log: https://syzkaller.appspot.com/x/fsck.log?x=110fbeef980000)

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+6e4cb1...@syzkaller.appspotmail.com

Oops: general protection fault, probably for non-canonical address 0xdffffc0000000006: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000030-0x0000000000000037]
CPU: 0 UID: 0 PID: 1041 Comm: kworker/u4:7 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Workqueue: loop0 loop_workfn
RIP: 0010:NODE_MAPPING fs/f2fs/f2fs.h:2260 [inline]
RIP: 0010:is_node_folio fs/f2fs/f2fs.h:2270 [inline]
RIP: 0010:f2fs_in_warm_node_list+0xbd/0x290 fs/f2fs/node.c:330
Code: 00 00 4d 03 3c 24 4c 89 f8 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 ff e8 61 3b f9 fd 4d 8b 3f 49 83 c7 30 4c 89 f8 48 c1 e8 03 <42> 80 3c 28 00 74 08 4c 89 ff e8 44 3b f9 fd 4d 3b 37 74 19 e8 7a
RSP: 0018:ffffc90005347488 EFLAGS: 00010206
RAX: 0000000000000006 RBX: ffffea0001521080 RCX: ffff88803683c900
RDX: 0000000000000000 RSI: ffffea0001521080 RDI: ffff8880546fc000
RBP: ffffea0001521098 R08: ffffffff901194b7 R09: 1ffffffff2023296
R10: dffffc0000000000 R11: fffffbfff2023297 R12: ffff888023ebe638
R13: dffffc0000000000 R14: ffff8880474d9490 R15: 0000000000000030
FS: 0000000000000000(0000) GS:ffff88808ca5b000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fbdbfabe000 CR3: 0000000056bbf000 CR4: 0000000000352ef0
Call Trace:
<TASK>
f2fs_write_end_io+0x7ab/0xff0 fs/f2fs/data.c:400
blk_update_request+0x57e/0xe60 block/blk-mq.c:1016
blk_mq_end_request+0x3e/0x70 block/blk-mq.c:1178
lo_rw_aio_complete drivers/block/loop.c:337 [inline]
lo_rw_aio+0xcde/0xf00 drivers/block/loop.c:410
do_req_filebacked drivers/block/loop.c:434 [inline]
loop_handle_cmd drivers/block/loop.c:1926 [inline]
loop_process_work+0x61d/0x11a0 drivers/block/loop.c:1961
process_one_work kernel/workqueue.c:3275 [inline]
process_scheduled_works+0xb02/0x1830 kernel/workqueue.c:3358
worker_thread+0xa50/0xfc0 kernel/workqueue.c:3439
kthread+0x388/0x470 kernel/kthread.c:467
ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:NODE_MAPPING fs/f2fs/f2fs.h:2260 [inline]
RIP: 0010:is_node_folio fs/f2fs/f2fs.h:2270 [inline]
RIP: 0010:f2fs_in_warm_node_list+0xbd/0x290 fs/f2fs/node.c:330
Code: 00 00 4d 03 3c 24 4c 89 f8 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 ff e8 61 3b f9 fd 4d 8b 3f 49 83 c7 30 4c 89 f8 48 c1 e8 03 <42> 80 3c 28 00 74 08 4c 89 ff e8 44 3b f9 fd 4d 3b 37 74 19 e8 7a
RSP: 0018:ffffc90005347488 EFLAGS: 00010206
RAX: 0000000000000006 RBX: ffffea0001521080 RCX: ffff88803683c900
RDX: 0000000000000000 RSI: ffffea0001521080 RDI: ffff8880546fc000
RBP: ffffea0001521098 R08: ffffffff901194b7 R09: 1ffffffff2023296
R10: dffffc0000000000 R11: fffffbfff2023297 R12: ffff888023ebe638
R13: dffffc0000000000 R14: ffff8880474d9490 R15: 0000000000000030
FS: 0000000000000000(0000) GS:ffff88808ca5b000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fbdbf9d3000 CR3: 0000000050969000 CR4: 0000000000352ef0
----------------
Code disassembly (best guess):
0: 00 00 add %al,(%rax)
2: 4d 03 3c 24 add (%r12),%r15
6: 4c 89 f8 mov %r15,%rax
9: 48 c1 e8 03 shr $0x3,%rax
d: 42 80 3c 28 00 cmpb $0x0,(%rax,%r13,1)
12: 74 08 je 0x1c
14: 4c 89 ff mov %r15,%rdi
17: e8 61 3b f9 fd call 0xfdf93b7d
1c: 4d 8b 3f mov (%r15),%r15
1f: 49 83 c7 30 add $0x30,%r15
23: 4c 89 f8 mov %r15,%rax
26: 48 c1 e8 03 shr $0x3,%rax
* 2a: 42 80 3c 28 00 cmpb $0x0,(%rax,%r13,1) <-- trapping instruction
2f: 74 08 je 0x39
31: 4c 89 ff mov %r15,%rdi
34: e8 44 3b f9 fd call 0xfdf93b7d
39: 4d 3b 37 cmp (%r15),%r14
3c: 74 19 je 0x57
3e: e8 .byte 0xe8
3f: 7a .byte 0x7a


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