Message-ID: <684f0067.050a0220.be214.02c2.GAE@google.com>
Date: Sun, 15 Jun 2025 10:18:31 -0700
From: syzbot <syzbot+bcdfadd9bda9988fa52a@...kaller.appspotmail.com>
To: chao@...nel.org, hch@....de, jaegeuk@...nel.org, 
	linux-f2fs-devel@...ts.sourceforge.net, linux-kernel@...r.kernel.org, 
	syzkaller-bugs@...glegroups.com
Subject: [syzbot] [f2fs?] kernel BUG in f2fs_sync_node_pages

Hello,

syzbot found the following issue on:

HEAD commit:    488ef3560196 KEYS: Invert FINAL_PUT bit
git tree:       upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=10e06d70580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=162faeb2d1eaefb4
dashboard link: https://syzkaller.appspot.com/bug?extid=bcdfadd9bda9988fa52a
compiler:       Debian clang version 20.1.6 (++20250514063057+1e4d39e07757-1~exp1~20250514183223.118), Debian LLD 20.1.6
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=13423682580000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=17423682580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/9bcad4b7e6e0/disk-488ef356.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/9ed0e62aacc9/vmlinux-488ef356.xz
kernel image: https://storage.googleapis.com/syzbot-assets/2e5e305c130c/bzImage-488ef356.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/ed472c7ffb63/mount_0.gz
  fsck result: failed (log: https://syzkaller.appspot.com/x/fsck.log?x=16b74e0c580000)

The issue was bisected to:

commit 80f31d2a7e5f4efa7150c951268236c670bcb068
Author: Christoph Hellwig <hch@....de>
Date:   Thu May 8 05:14:32 2025 +0000

    f2fs: return bool from __write_node_folio

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=149f3682580000
final oops:     https://syzkaller.appspot.com/x/report.txt?x=169f3682580000
console output: https://syzkaller.appspot.com/x/log.txt?x=129f3682580000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+bcdfadd9bda9988fa52a@...kaller.appspotmail.com
Fixes: 80f31d2a7e5f ("f2fs: return bool from __write_node_folio")

 f2fs_get_new_data_folio+0x138/0x870 fs/f2fs/data.c:1363
 f2fs_add_regular_entry+0x5a3/0xc10 fs/f2fs/dir.c:702
 f2fs_add_dentry+0xda/0x1d0 fs/f2fs/dir.c:771
 f2fs_do_add_link+0x20f/0x3b0 fs/f2fs/dir.c:810
 f2fs_add_link fs/f2fs/f2fs.h:3717 [inline]
 f2fs_create+0x337/0x5c0 fs/f2fs/namei.c:380
page last free pid 5818 tgid 5818 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1248 [inline]
 __free_frozen_pages+0xc65/0xe60 mm/page_alloc.c:2706
 __folio_put+0x21b/0x2c0 mm/swap.c:112
 pipe_buf_release include/linux/pipe_fs_i.h:282 [inline]
 pipe_update_tail fs/pipe.c:242 [inline]
 anon_pipe_read+0x643/0x1040 fs/pipe.c:361
 new_sync_read fs/read_write.c:491 [inline]
 vfs_read+0x4d0/0x980 fs/read_write.c:572
 ksys_read+0x145/0x250 fs/read_write.c:715
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
------------[ cut here ]------------
kernel BUG at mm/filemap.c:1498!
Oops: invalid opcode: 0000 [#1] SMP KASAN PTI
CPU: 0 UID: 0 PID: 12 Comm: kworker/u8:0 Not tainted 6.16.0-rc1-syzkaller-00005-g488ef3560196 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: writeback wb_workfn (flush-7:0)
RIP: 0010:folio_unlock+0x13d/0x160 mm/filemap.c:1498
Code: de c8 ff 48 89 df 48 c7 c6 a0 36 94 8b e8 cb 6d 0e 00 90 0f 0b e8 13 de c8 ff 48 89 df 48 c7 c6 c0 2c 94 8b e8 b4 6d 0e 00 90 <0f> 0b e8 fc dd c8 ff 48 89 df 48 c7 c6 a0 36 94 8b e8 9d 6d 0e 00
RSP: 0018:ffffc90000116e28 EFLAGS: 00010246
RAX: ee13dd9e63919500 RBX: ffffea0001d33080 RCX: 0000000000000000
RDX: 0000000000000006 RSI: ffffffff8d96d7f4 RDI: 00000000ffffffff
RBP: ffffc90000117110 R08: ffffffff8f9fdef7 R09: 1ffffffff1f3fbde
R10: dffffc0000000000 R11: fffffbfff1f3fbdf R12: 1ffffd40003a6611
R13: 00fff00000004018 R14: ffffea0001d33088 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff888125c86000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa0ebcd1130 CR3: 0000000031646000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 f2fs_sync_node_pages+0x180a/0x1a10 fs/f2fs/node.c:2081
 f2fs_write_node_pages+0x303/0x6e0 fs/f2fs/node.c:2183
 do_writepages+0x32b/0x550 mm/page-writeback.c:2636
 __writeback_single_inode+0x145/0xff0 fs/fs-writeback.c:1680
 writeback_sb_inodes+0x6b5/0x1000 fs/fs-writeback.c:1976
 wb_writeback+0x43b/0xaf0 fs/fs-writeback.c:2156
 wb_do_writeback fs/fs-writeback.c:2303 [inline]
 wb_workfn+0x409/0xef0 fs/fs-writeback.c:2343
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3321
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402
 kthread+0x70e/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:folio_unlock+0x13d/0x160 mm/filemap.c:1498
Code: de c8 ff 48 89 df 48 c7 c6 a0 36 94 8b e8 cb 6d 0e 00 90 0f 0b e8 13 de c8 ff 48 89 df 48 c7 c6 c0 2c 94 8b e8 b4 6d 0e 00 90 <0f> 0b e8 fc dd c8 ff 48 89 df 48 c7 c6 a0 36 94 8b e8 9d 6d 0e 00
RSP: 0018:ffffc90000116e28 EFLAGS: 00010246
RAX: ee13dd9e63919500 RBX: ffffea0001d33080 RCX: 0000000000000000
RDX: 0000000000000006 RSI: ffffffff8d96d7f4 RDI: 00000000ffffffff
RBP: ffffc90000117110 R08: ffffffff8f9fdef7 R09: 1ffffffff1f3fbde
R10: dffffc0000000000 R11: fffffbfff1f3fbdf R12: 1ffffd40003a6611
R13: 00fff00000004018 R14: ffffea0001d33088 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff888125d86000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005555844206f8 CR3: 0000000028e76000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


---
This report is generated by a bot. It may contain errors.
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For information about bisection process see: https://goo.gl/tpsmEJ#bisection

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

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