Re: [f2fs-dev] [syzbot] [f2fs?] general protection fault in f2fs_in_warm_node_list

[syzbot <syzbot+6e4cb1cac5efc96ea0ca@syzkaller.appspotmail.com>]

syzbot has found a reproducer for the following issue on:

HEAD commit:    d79526b89571 Merge tag 'spi-fix-v7.0-merge-window' of git:..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=16898f3a580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=abe4fa590468dbfb
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=1230d722580000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=11638152580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/44c805790970/disk-d79526b8.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/1ce6fb543c09/vmlinux-d79526b8.xz
kernel image: https://storage.googleapis.com/syzbot-assets/e59b179ab15c/bzImage-d79526b8.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/6c7449a54d18/mount_0.gz
  fsck result: failed (log: https://syzkaller.appspot.com/x/fsck.log?x=16e5255a580000)

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+6e4cb1cac5efc96ea0ca@syzkaller.appspotmail.com

Oops: general protection fault, probably for non-canonical address 0xdffffc0000000006: 0000 [#1] SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000030-0x0000000000000037]
CPU: 1 UID: 0 PID: 30 Comm: ksoftirqd/1 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
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 31 ab fd 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 14 ab fd fd 4d 3b 37 74 19 e8 4a
RSP: 0018:ffffc90000a4f9a8 EFLAGS: 00010206
RAX: 0000000000000006 RBX: ffffea0000c14dc0 RCX: ffff88801d2b9e40
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000100
RBP: ffffea0000c14dd8 R08: ffff88803746002b R09: 1ffff11006e8c005
R10: dffffc0000000000 R11: ffffed1006e8c006 R12: ffff88803471e798
R13: dffffc0000000000 R14: ffff888045f67750 R15: 0000000000000030
FS:  0000000000000000(0000) GS:ffff888126442000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffda58b1c70 CR3: 000000003ab1a000 CR4: 00000000003526f0
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
 blk_flush_complete_seq+0x687/0xce0 block/blk-flush.c:191
 flush_end_io+0xc40/0xf30 block/blk-flush.c:251
 __blk_mq_end_request+0x4a9/0x680 block/blk-mq.c:1168
 blk_complete_reqs block/blk-mq.c:1253 [inline]
 blk_done_softirq+0x10a/0x160 block/blk-mq.c:1258
 handle_softirqs+0x1de/0x6f0 kernel/softirq.c:622
 run_ksoftirqd+0x52/0x180 kernel/softirq.c:1063
 smpboot_thread_fn+0x541/0xa50 kernel/smpboot.c:160
 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 31 ab fd 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 14 ab fd fd 4d 3b 37 74 19 e8 4a
RSP: 0018:ffffc90000a4f9a8 EFLAGS: 00010206
RAX: 0000000000000006 RBX: ffffea0000c14dc0 RCX: ffff88801d2b9e40
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000100
RBP: ffffea0000c14dd8 R08: ffff88803746002b R09: 1ffff11006e8c005
R10: dffffc0000000000 R11: ffffed1006e8c006 R12: ffff88803471e798
R13: dffffc0000000000 R14: ffff888045f67750 R15: 0000000000000030
FS:  0000000000000000(0000) GS:ffff888126442000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffda58b1c70 CR3: 000000003ab1a000 CR4: 00000000003526f0
----------------
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 31 ab fd fd       	call   0xfdfdab4d
  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 14 ab fd fd       	call   0xfdfdab4d
  39:	4d 3b 37             	cmp    (%r15),%r14
  3c:	74 19                	je     0x57
  3e:	e8                   	.byte 0xe8
  3f:	4a                   	rex.WX


---
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.


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