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From:   Miklos Szeredi <miklos@szeredi.hu>
Date:   Wed, 20 Apr 2022 17:14:06 +0200
Message-ID: <CAJfpegsd-TokH5b8pgLr2mR2QQq7u-_E+8LYMwkT5BCtEyPffA@mail.gmail.com>
Subject: Re: [syzbot] WARNING in fuse_writepage_locked
To:     syzbot <syzbot+d0dd8d6b123d46c4dcf2@syzkaller.appspotmail.com>
Cc:     linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
        syzkaller-bugs <syzkaller-bugs@googlegroups.com>
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On Sun, 21 Nov 2021 at 21:29, syzbot
<syzbot+d0dd8d6b123d46c4dcf2@syzkaller.appspotmail.com> wrote:
>
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit:    42eb8fdac2fc Merge tag 'gfs2-v5.16-rc2-fixes' of git://git..
> git tree:       upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=137ec159b00000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=6d3b8fd1977c1e73
> dashboard link: https://syzkaller.appspot.com/bug?extid=d0dd8d6b123d46c4dcf2
> compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
>
> Unfortunately, I don't have any reproducer for this issue yet.

Likely a dup:

#syz dup: WARNING in fuse_write_file_get

>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+d0dd8d6b123d46c4dcf2@syzkaller.appspotmail.com
>
> WARNING: CPU: 1 PID: 17813 at fs/fuse/file.c:1833 fuse_write_file_get fs/fuse/file.c:1833 [inline]
> WARNING: CPU: 1 PID: 17813 at fs/fuse/file.c:1833 fuse_write_file_get fs/fuse/file.c:1830 [inline]
> WARNING: CPU: 1 PID: 17813 at fs/fuse/file.c:1833 fuse_writepage_locked+0xa84/0xd40 fs/fuse/file.c:1918
> Modules linked in:
> CPU: 1 PID: 17813 Comm: syz-executor.2 Not tainted 5.16.0-rc1-syzkaller #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
> RIP: 0010:fuse_write_file_get fs/fuse/file.c:1833 [inline]
> RIP: 0010:fuse_write_file_get fs/fuse/file.c:1830 [inline]
> RIP: 0010:fuse_writepage_locked+0xa84/0xd40 fs/fuse/file.c:1918
> Code: 20 5b 5d 41 5c 41 5d 41 5e 41 5f c3 41 bc f4 ff ff ff e9 2d ff ff ff e8 8a dd c6 fe 48 8b 3c 24 e8 b1 fe a3 06 e8 7c dd c6 fe <0f> 0b 49 8d be c8 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa
> RSP: 0018:ffffc90018f3f5f0 EFLAGS: 00010212
> RAX: 000000000000a311 RBX: ffff8880834ba688 RCX: ffffc9000d9e9000
> RDX: 0000000000040000 RSI: ffffffff82b10a64 RDI: 0000000000000001
> RBP: ffffea0000263e40 R08: 0000000000000000 R09: ffff8880834ba7a3
> R10: ffffed10106974f4 R11: 000000000000001f R12: ffff8880834ba1c0
> R13: ffffea000258d080 R14: ffff888018b83c00 R15: ffff88814a7ac800
> FS:  00007f75e4cad700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 00007ffc15c0ef7c CR3: 0000000073f74000 CR4: 0000000000350ee0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
> Call Trace:
>  <TASK>
>  fuse_writepage+0x104/0x160 fs/fuse/file.c:1976
>  writeout mm/migrate.c:826 [inline]
>  fallback_migrate_page mm/migrate.c:850 [inline]
>  move_to_new_page+0x7ea/0xf00 mm/migrate.c:901
>  __unmap_and_move mm/migrate.c:1063 [inline]
>  unmap_and_move mm/migrate.c:1204 [inline]
>  migrate_pages+0x27f5/0x3810 mm/migrate.c:1481
>  compact_zone+0x1abb/0x3860 mm/compaction.c:2399
>  compact_node+0x129/0x1f0 mm/compaction.c:2683
>  compact_nodes mm/compaction.c:2699 [inline]
>  sysctl_compaction_handler+0x10e/0x160 mm/compaction.c:2741
>  proc_sys_call_handler+0x437/0x620 fs/proc/proc_sysctl.c:586
>  call_write_iter include/linux/fs.h:2162 [inline]
>  new_sync_write+0x429/0x660 fs/read_write.c:503
>  vfs_write+0x7cd/0xae0 fs/read_write.c:590
>  ksys_write+0x12d/0x250 fs/read_write.c:643
>  do_syscall_x64 arch/x86/entry/common.c:50 [inline]
>  do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
>  entry_SYSCALL_64_after_hwframe+0x44/0xae
> RIP: 0033:0x7f75e7737ae9
> Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
> RSP: 002b:00007f75e4cad188 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
> RAX: ffffffffffffffda RBX: 00007f75e784af60 RCX: 00007f75e7737ae9
> RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004
> RBP: 00007f75e7791f6d R08: 0000000000000000 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
> R13: 00007ffee68ffeff R14: 00007f75e4cad300 R15: 0000000000022000
>  </TASK>
>
>
> ---
> 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@googlegroups.com.
>
> syzbot will keep track of this issue. See:
> https://goo.gl/tpsmEJ#status for how to communicate with syzbot.