Re: [syzbot] [xfs?] INFO: task hung in clean_bdev_aliases

[Aleksandr Nogikh]

On Tue, Sep 5, 2023 at 11:14 PM 'Dave Chinner' via syzkaller-bugs
<syzkaller-bugs@xxxxxxxxxxxxxxxx> wrote:
>
> [cc linux-block, Christoph]
>
> Another iomap-blockdev related issue.
>
> #syz set subsystems: block
>
> syzbot developers: Please review how you are classifying subsystems,
> this is the third false XFS classification in 24 hours.

The reason why syzbot marked this report as xfs is that, per
MAINTAINERS, fs/iomap/ points to linux-xfs@xxxxxxxxxxxxxxx. I can
adjust the rules syzbot uses so that these are routed to "block".

But should MAINTAINERS actually also not relate IOMAP FILESYSTEM
LIBRARY with xfs in this case?

-- 
Aleksandr

>
> -Dave.
>
> On Mon, Sep 04, 2023 at 10:04:47PM -0700, syzbot wrote:
> > Hello,
> >
> > syzbot found the following issue on:
> >
> > HEAD commit:    92901222f83d Merge tag 'f2fs-for-6-6-rc1' of git://git.ker..
> > git tree:       upstream
> > console+strace: https://syzkaller.appspot.com/x/log.txt?x=1485e78fa80000
> > kernel config:  https://syzkaller.appspot.com/x/.config?x=3bd57a1ac08277b0
> > dashboard link: https://syzkaller.appspot.com/bug?extid=1fa947e7f09e136925b8
> > compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
> > syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=13fcf738680000
> >
> > Downloadable assets:
> > disk image: https://storage.googleapis.com/syzbot-assets/ee486d884228/disk-92901222.raw.xz
> > vmlinux: https://storage.googleapis.com/syzbot-assets/b5187db0b1d1/vmlinux-92901222.xz
> > kernel image: https://storage.googleapis.com/syzbot-assets/82c4e42d693e/bzImage-92901222.xz
> >
> > IMPORTANT: if you fix the issue, please add the following tag to the commit:
> > Reported-by: syzbot+1fa947e7f09e136925b8@xxxxxxxxxxxxxxxxxxxxxxxxx
> >
> > INFO: task syz-executor.5:10017 blocked for more than 143 seconds.
> >       Not tainted 6.5.0-syzkaller-11075-g92901222f83d #0
> > "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
> > task:syz-executor.5  state:D stack:27624 pid:10017 ppid:5071   flags:0x00004006
> > Call Trace:
> >  <TASK>
> >  context_switch kernel/sched/core.c:5382 [inline]
> >  __schedule+0xee1/0x59f0 kernel/sched/core.c:6695
> >  schedule+0xe7/0x1b0 kernel/sched/core.c:6771
> >  io_schedule+0xbe/0x130 kernel/sched/core.c:9026
> >  folio_wait_bit_common+0x3d2/0x9b0 mm/filemap.c:1304
> >  folio_lock include/linux/pagemap.h:1042 [inline]
> >  clean_bdev_aliases+0x56b/0x610 fs/buffer.c:1725
> >  clean_bdev_bh_alias include/linux/buffer_head.h:219 [inline]
> >  __block_write_begin_int+0x8d6/0x1470 fs/buffer.c:2115
> >  iomap_write_begin+0x5be/0x17b0 fs/iomap/buffered-io.c:772
> >  iomap_write_iter fs/iomap/buffered-io.c:907 [inline]
> >  iomap_file_buffered_write+0x3d6/0x9a0 fs/iomap/buffered-io.c:968
> >  blkdev_buffered_write block/fops.c:634 [inline]
> >  blkdev_write_iter+0x572/0xca0 block/fops.c:688
> >  call_write_iter include/linux/fs.h:1985 [inline]
> >  do_iter_readv_writev+0x21e/0x3c0 fs/read_write.c:735
> >  do_iter_write+0x17f/0x830 fs/read_write.c:860
> >  vfs_iter_write+0x7a/0xb0 fs/read_write.c:901
> >  iter_file_splice_write+0x698/0xbf0 fs/splice.c:736
> >  do_splice_from fs/splice.c:933 [inline]
> >  direct_splice_actor+0x118/0x180 fs/splice.c:1142
> >  splice_direct_to_actor+0x347/0xa30 fs/splice.c:1088
> >  do_splice_direct+0x1af/0x280 fs/splice.c:1194
> >  do_sendfile+0xb88/0x1390 fs/read_write.c:1254
> >  __do_sys_sendfile64 fs/read_write.c:1322 [inline]
> >  __se_sys_sendfile64 fs/read_write.c:1308 [inline]
> >  __x64_sys_sendfile64+0x1d6/0x220 fs/read_write.c:1308
> >  do_syscall_x64 arch/x86/entry/common.c:50 [inline]
> >  do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80
> >  entry_SYSCALL_64_after_hwframe+0x63/0xcd
> > RIP: 0033:0x7fdb8ca7cae9
> > RSP: 002b:00007ffcd642da18 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
> > RAX: ffffffffffffffda RBX: 00007fdb8cb9bf80 RCX: 00007fdb8ca7cae9
> > RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000003
> > RBP: 00007fdb8cac847a R08: 0000000000000000 R09: 0000000000000000
> > R10: 0100000000000042 R11: 0000000000000246 R12: 0000000000000000
> > R13: 0000000000000be7 R14: 00007fdb8cb9bf80 R15: 00007fdb8cb9bf80
> >  </TASK>
> > INFO: lockdep is turned off.
> > NMI backtrace for cpu 1
> > CPU: 1 PID: 29 Comm: khungtaskd Not tainted 6.5.0-syzkaller-11075-g92901222f83d #0
> > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023
> > Call Trace:
> >  <TASK>
> >  __dump_stack lib/dump_stack.c:88 [inline]
> >  dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106
> >  nmi_cpu_backtrace+0x277/0x380 lib/nmi_backtrace.c:113
> >  nmi_trigger_cpumask_backtrace+0x299/0x300 lib/nmi_backtrace.c:62
> >  trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
> >  check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
> >  watchdog+0xfac/0x1230 kernel/hung_task.c:379
> >  kthread+0x33a/0x430 kernel/kthread.c:388
> >  ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
> >  ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304
> >  </TASK>
> > Sending NMI from CPU 1 to CPUs 0:
> > NMI backtrace for cpu 0
> > CPU: 0 PID: 17 Comm: rcu_preempt Not tainted 6.5.0-syzkaller-11075-g92901222f83d #0
> > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023
> > RIP: 0010:load_balance+0x10a/0x3130 kernel/sched/fair.c:10983
> > Code: 4a 8d 3c f5 40 aa 5c 8c 48 ba 00 00 00 00 00 fc ff df 48 89 f9 48 c1 e9 03 80 3c 11 00 0f 85 2f 2e 00 00 31 c0 b9 0c 00 00 00 <4e> 8b 1c f5 40 aa 5c 8c 4c 89 94 24 f8 00 00 00 48 8d bc 24 00 01
> > RSP: 0018:ffffc900001676c8 EFLAGS: 00000046
> > RAX: 0000000000000000 RBX: ffff8880b983c700 RCX: 000000000000000c
> > RDX: dffffc0000000000 RSI: ffffffff8ae90360 RDI: ffffffff8c5caa40
> > RBP: ffffc90000167898 R08: ffffc90000167960 R09: 0000000000000000
> > R10: ffff88801525ac00 R11: 0000000000000000 R12: 00000000000287d8
> > R13: ffffc90000167960 R14: 0000000000000000 R15: 0000000100004d48
> > FS:  0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
> > CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> > CR2: 0000000020000240 CR3: 000000000c976000 CR4: 0000000000350ef0
> > Call Trace:
> >  <NMI>
> >  </NMI>
> >  <TASK>
> >  newidle_balance+0x710/0x1210 kernel/sched/fair.c:12059
> >  pick_next_task_fair+0x87/0x1200 kernel/sched/fair.c:8234
> >  __pick_next_task kernel/sched/core.c:6004 [inline]
> >  pick_next_task kernel/sched/core.c:6079 [inline]
> >  __schedule+0x493/0x59f0 kernel/sched/core.c:6659
> >  schedule+0xe7/0x1b0 kernel/sched/core.c:6771
> >  schedule_timeout+0x157/0x2c0 kernel/time/timer.c:2167
> >  rcu_gp_fqs_loop+0x1ec/0xa50 kernel/rcu/tree.c:1613
> >  rcu_gp_kthread+0x249/0x380 kernel/rcu/tree.c:1812
> >  kthread+0x33a/0x430 kernel/kthread.c:388
> >  ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
> >  ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304
> >  </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@xxxxxxxxxxxxxxxx.
> >
> > syzbot will keep track of this issue. See:
> > https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
> >
> > If the bug is already fixed, 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 bug's subsystems, reply with:
> > #syz set subsystems: new-subsystem
> > (See the list of subsystem names on the web dashboard)
> >
> > If the bug is a duplicate of another bug, reply with:
> > #syz dup: exact-subject-of-another-report
> >
> > If you want to undo deduplication, reply with:
> > #syz undup
> >
>
> --
> Dave Chinner
> david@xxxxxxxxxxxxx
>