Message-ID: <1c900b10-d610-4077-bad5-05e1d9f0d7fe@kernel.org>
Date: Wed, 24 Sep 2025 10:34:07 +0800
From: Chao Yu <chao@...nel.org>
To: syzbot <syzbot+bcdfadd9bda9988fa52a@...kaller.appspotmail.com>,
 hch@....de, jaegeuk@...nel.org, linux-f2fs-devel@...ts.sourceforge.net,
 linux-kernel@...r.kernel.org, syzkaller-bugs@...glegroups.com
Cc: chao@...nel.org
Subject: Re: [syzbot] [f2fs?] kernel BUG in f2fs_sync_node_pages

#syz fix f2fs: Fix __write_node_folio() conversion

On 6/16/2025 1:18 AM, syzbot wrote:
> 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.
> See https://goo.gl/tpsmEJ for more information about syzbot.
> syzbot engineers can be reached at syzkaller@...glegroups.com.
> 
> syzbot will keep track of this issue. See:
> https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
> 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
> 
> 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

Powered by blists - more mailing lists