On Mon, Jan 29, 2024 at 2:15 AM syzbot <syzbot+ee2ae68da3b22d04cd8d@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > > Hello, > > syzbot found the following issue on: > > HEAD commit: 0802e17d9aca Merge branch 'for-next/core' into for-kernelci > git tree: git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci > console output: https://syzkaller.appspot.com/x/log.txt?x=10832107e80000 > kernel config: https://syzkaller.appspot.com/x/.config?x=f9616b7e180577ba > dashboard link: https://syzkaller.appspot.com/bug?extid=ee2ae68da3b22d04cd8d > compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 > userspace arch: arm64 > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=163043bfe80000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1306c1e3e80000 > > Downloadable assets: > disk image: https://storage.googleapis.com/syzbot-assets/e84e45f27a78/disk-0802e17d.raw.xz > vmlinux: https://storage.googleapis.com/syzbot-assets/a8b16d2fc3b1/vmlinux-0802e17d.xz > kernel image: https://storage.googleapis.com/syzbot-assets/4c7ac36b3de1/Image-0802e17d.gz.xz > mounted in repro: https://storage.googleapis.com/syzbot-assets/e31cee0eb927/mount_10.gz > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+ee2ae68da3b22d04cd8d@xxxxxxxxxxxxxxxxxxxxxxxxx > > INFO: task syz-executor439:7446 blocked for more than 143 seconds. > Not tainted 6.7.0-rc8-syzkaller-g0802e17d9aca #0 > "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. > task:syz-executor439 state:D stack:0 pid:7446 tgid:7429 ppid:6155 flags:0x0000000d > Call trace: > __switch_to+0x314/0x560 arch/arm64/kernel/process.c:556 > context_switch kernel/sched/core.c:5376 [inline] > __schedule+0x1354/0x2360 kernel/sched/core.c:6688 > __schedule_loop kernel/sched/core.c:6763 [inline] > schedule+0xb8/0x19c kernel/sched/core.c:6778 > io_schedule+0x8c/0x12c kernel/sched/core.c:8998 > folio_wait_bit_common+0x65c/0xb90 mm/filemap.c:1273 > folio_wait_bit+0x30/0x40 mm/filemap.c:1412 > folio_wait_writeback+0x14c/0x3bc mm/page-writeback.c:3065 > migrate_folio_unmap mm/migrate.c:1191 [inline] > migrate_pages_batch+0xc1c/0x25b0 mm/migrate.c:1680 > migrate_pages_sync mm/migrate.c:1873 [inline] > migrate_pages+0x1bf8/0x3114 mm/migrate.c:1955 > do_mbind mm/mempolicy.c:1344 [inline] > kernel_mbind mm/mempolicy.c:1486 [inline] > __do_sys_mbind mm/mempolicy.c:1560 [inline] > __se_sys_mbind mm/mempolicy.c:1556 [inline] > __arm64_sys_mbind+0x1410/0x18e8 mm/mempolicy.c:1556 > __invoke_syscall arch/arm64/kernel/syscall.c:37 [inline] > invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:51 > el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:136 > do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:155 > el0_svc+0x54/0x158 arch/arm64/kernel/entry-common.c:678 > el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:696 > el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:595 > INFO: task segctord:7440 blocked for more than 143 seconds. > Not tainted 6.7.0-rc8-syzkaller-g0802e17d9aca #0 > "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. > task:segctord state:D stack:0 pid:7440 tgid:7440 ppid:2 flags:0x00000008 > Call trace: > __switch_to+0x314/0x560 arch/arm64/kernel/process.c:556 > context_switch kernel/sched/core.c:5376 [inline] > __schedule+0x1354/0x2360 kernel/sched/core.c:6688 > __schedule_loop kernel/sched/core.c:6763 [inline] > schedule+0xb8/0x19c kernel/sched/core.c:6778 > io_schedule+0x8c/0x12c kernel/sched/core.c:8998 > folio_wait_bit_common+0x65c/0xb90 mm/filemap.c:1273 > __folio_lock+0x2c/0x3c mm/filemap.c:1611 > folio_lock include/linux/pagemap.h:1031 [inline] > nilfs_lookup_dirty_data_buffers+0x2b0/0x7e8 fs/nilfs2/segment.c:727 > nilfs_segctor_scan_file+0x1e4/0xcdc fs/nilfs2/segment.c:1084 > nilfs_segctor_collect_blocks fs/nilfs2/segment.c:1206 [inline] > nilfs_segctor_collect fs/nilfs2/segment.c:1533 [inline] > nilfs_segctor_do_construct+0x16ec/0x6560 fs/nilfs2/segment.c:2081 > nilfs_segctor_construct+0x110/0x768 fs/nilfs2/segment.c:2415 > nilfs_segctor_thread_construct fs/nilfs2/segment.c:2523 [inline] > nilfs_segctor_thread+0x3d4/0xd74 fs/nilfs2/segment.c:2606 > kthread+0x288/0x310 kernel/kthread.c:388 > ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:857 > INFO: task syz-executor439:7442 blocked for more than 143 seconds. > Not tainted 6.7.0-rc8-syzkaller-g0802e17d9aca #0 > "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. > task:syz-executor439 state:D stack:0 pid:7442 tgid:7441 ppid:6156 flags:0x0000000d > Call trace: > __switch_to+0x314/0x560 arch/arm64/kernel/process.c:556 > context_switch kernel/sched/core.c:5376 [inline] > __schedule+0x1354/0x2360 kernel/sched/core.c:6688 > __schedule_loop kernel/sched/core.c:6763 [inline] > schedule+0xb8/0x19c kernel/sched/core.c:6778 > wb_wait_for_completion+0x154/0x29c fs/fs-writeback.c:192 > sync_inodes_sb+0x220/0x944 fs/fs-writeback.c:2758 > sync_inodes_one_sb+0x58/0x70 fs/sync.c:77 > iterate_supers+0xd4/0x188 fs/super.c:971 > ksys_sync+0xb4/0x1cc fs/sync.c:102 > __arm64_sys_sync+0x14/0x24 fs/sync.c:113 > __invoke_syscall arch/arm64/kernel/syscall.c:37 [inline] > invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:51 > el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:136 > do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:155 > el0_svc+0x54/0x158 arch/arm64/kernel/entry-common.c:678 > el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:696 > el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:595 > INFO: task syz-executor439:7445 blocked for more than 143 seconds. > Not tainted 6.7.0-rc8-syzkaller-g0802e17d9aca #0 > "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. > task:syz-executor439 state:D stack:0 pid:7445 tgid:7444 ppid:6160 flags:0x0000000d > Call trace: > __switch_to+0x314/0x560 arch/arm64/kernel/process.c:556 > context_switch kernel/sched/core.c:5376 [inline] > __schedule+0x1354/0x2360 kernel/sched/core.c:6688 > __schedule_loop kernel/sched/core.c:6763 [inline] > schedule+0xb8/0x19c kernel/sched/core.c:6778 > schedule_preempt_disabled+0x18/0x2c kernel/sched/core.c:6835 > rwsem_down_write_slowpath+0xcfc/0x1aa0 kernel/locking/rwsem.c:1178 > __down_write_common kernel/locking/rwsem.c:1306 [inline] > __down_write kernel/locking/rwsem.c:1315 [inline] > down_write+0xb4/0xc0 kernel/locking/rwsem.c:1580 > bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:364 [inline] > sync_inodes_sb+0x208/0x944 fs/fs-writeback.c:2756 > sync_inodes_one_sb+0x58/0x70 fs/sync.c:77 > iterate_supers+0xd4/0x188 fs/super.c:971 > ksys_sync+0xb4/0x1cc fs/sync.c:102 > __arm64_sys_sync+0x14/0x24 fs/sync.c:113 > __invoke_syscall arch/arm64/kernel/syscall.c:37 [inline] > invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:51 > el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:136 > do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:155 > el0_svc+0x54/0x158 arch/arm64/kernel/entry-common.c:678 > el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:696 > el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:595 > INFO: task syz-executor439:7450 blocked for more than 143 seconds. > Not tainted 6.7.0-rc8-syzkaller-g0802e17d9aca #0 > "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. > task:syz-executor439 state:D stack:0 pid:7450 tgid:7448 ppid:6153 flags:0x0000000d > Call trace: > __switch_to+0x314/0x560 arch/arm64/kernel/process.c:556 > context_switch kernel/sched/core.c:5376 [inline] > __schedule+0x1354/0x2360 kernel/sched/core.c:6688 > __schedule_loop kernel/sched/core.c:6763 [inline] > schedule+0xb8/0x19c kernel/sched/core.c:6778 > schedule_preempt_disabled+0x18/0x2c kernel/sched/core.c:6835 > rwsem_down_write_slowpath+0xcfc/0x1aa0 kernel/locking/rwsem.c:1178 > __down_write_common kernel/locking/rwsem.c:1306 [inline] > __down_write kernel/locking/rwsem.c:1315 [inline] > down_write+0xb4/0xc0 kernel/locking/rwsem.c:1580 > bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:364 [inline] > sync_inodes_sb+0x208/0x944 fs/fs-writeback.c:2756 > sync_inodes_one_sb+0x58/0x70 fs/sync.c:77 > iterate_supers+0xd4/0x188 fs/super.c:971 > ksys_sync+0xb4/0x1cc fs/sync.c:102 > __arm64_sys_sync+0x14/0x24 fs/sync.c:113 > __invoke_syscall arch/arm64/kernel/syscall.c:37 [inline] > invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:51 > el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:136 > do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:155 > el0_svc+0x54/0x158 arch/arm64/kernel/entry-common.c:678 > el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:696 > el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:595 > INFO: task syz-executor439:7451 blocked for more than 143 seconds. > Not tainted 6.7.0-rc8-syzkaller-g0802e17d9aca #0 > "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. > task:syz-executor439 state:D stack:0 pid:7451 tgid:7449 ppid:6154 flags:0x0000000d > Call trace: > __switch_to+0x314/0x560 arch/arm64/kernel/process.c:556 > context_switch kernel/sched/core.c:5376 [inline] > __schedule+0x1354/0x2360 kernel/sched/core.c:6688 > __schedule_loop kernel/sched/core.c:6763 [inline] > schedule+0xb8/0x19c kernel/sched/core.c:6778 > schedule_preempt_disabled+0x18/0x2c kernel/sched/core.c:6835 > rwsem_down_write_slowpath+0xcfc/0x1aa0 kernel/locking/rwsem.c:1178 > __down_write_common kernel/locking/rwsem.c:1306 [inline] > __down_write kernel/locking/rwsem.c:1315 [inline] > down_write+0xb4/0xc0 kernel/locking/rwsem.c:1580 > bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:364 [inline] > sync_inodes_sb+0x208/0x944 fs/fs-writeback.c:2756 > sync_inodes_one_sb+0x58/0x70 fs/sync.c:77 > iterate_supers+0xd4/0x188 fs/super.c:971 > ksys_sync+0xb4/0x1cc fs/sync.c:102 > __arm64_sys_sync+0x14/0x24 fs/sync.c:113 > __invoke_syscall arch/arm64/kernel/syscall.c:37 [inline] > invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:51 > el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:136 > do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:155 > el0_svc+0x54/0x158 arch/arm64/kernel/entry-common.c:678 > el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:696 > el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:595 > INFO: task syz-executor439:7460 blocked for more than 143 seconds. > Not tainted 6.7.0-rc8-syzkaller-g0802e17d9aca #0 > "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. > task:syz-executor439 state:D stack:0 pid:7460 tgid:7456 ppid:6161 flags:0x0000000d > Call trace: > __switch_to+0x314/0x560 arch/arm64/kernel/process.c:556 > context_switch kernel/sched/core.c:5376 [inline] > __schedule+0x1354/0x2360 kernel/sched/core.c:6688 > __schedule_loop kernel/sched/core.c:6763 [inline] > schedule+0xb8/0x19c kernel/sched/core.c:6778 > schedule_preempt_disabled+0x18/0x2c kernel/sched/core.c:6835 > rwsem_down_write_slowpath+0xcfc/0x1aa0 kernel/locking/rwsem.c:1178 > __down_write_common kernel/locking/rwsem.c:1306 [inline] > __down_write kernel/locking/rwsem.c:1315 [inline] > down_write+0xb4/0xc0 kernel/locking/rwsem.c:1580 > bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:364 [inline] > sync_inodes_sb+0x208/0x944 fs/fs-writeback.c:2756 > sync_inodes_one_sb+0x58/0x70 fs/sync.c:77 > iterate_supers+0xd4/0x188 fs/super.c:971 > ksys_sync+0xb4/0x1cc fs/sync.c:102 > __arm64_sys_sync+0x14/0x24 fs/sync.c:113 > __invoke_syscall arch/arm64/kernel/syscall.c:37 [inline] > invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:51 > el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:136 > do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:155 > el0_svc+0x54/0x158 arch/arm64/kernel/entry-common.c:678 > el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:696 > el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:595 > > Showing all locks held in the system: > 1 lock held by khungtaskd/29: > #0: ffff80008e6c48c0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0xc/0x44 include/linux/rcupdate.h:300 > 2 locks held by kworker/u4:3/41: > #0: ffff0000c1c3a138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x560/0x1204 kernel/workqueue.c:2600 > #1: ffff8000943f7c20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x5a0/0x1204 kernel/workqueue.c:2602 > 2 locks held by getty/5863: > #0: ffff0000d255f0a0 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x3c/0x4c drivers/tty/tty_ldsem.c:340 > #1: ffff800094e702f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x41c/0x1228 drivers/tty/n_tty.c:2201 > 1 lock held by segctord/7440: > #0: ffff0000c7ade2a0 (&nilfs->ns_segctor_sem){++++}-{3:3}, at: nilfs_transaction_lock+0x178/0x33c fs/nilfs2/segment.c:357 > 2 locks held by syz-executor439/7442: > #0: ffff0000c5e920e0 (&type->s_umount_key#64){++++}-{3:3}, at: __super_lock fs/super.c:58 [inline] > #0: ffff0000c5e920e0 (&type->s_umount_key#64){++++}-{3:3}, at: super_lock+0x160/0x328 fs/super.c:117 > #1: ffff0000c9d147d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:364 [inline] > #1: ffff0000c9d147d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x208/0x944 fs/fs-writeback.c:2756 > 2 locks held by syz-executor439/7445: > #0: ffff0000c5e920e0 (&type->s_umount_key#64){++++}-{3:3}, at: __super_lock fs/super.c:58 [inline] > #0: ffff0000c5e920e0 (&type->s_umount_key#64){++++}-{3:3}, at: super_lock+0x160/0x328 fs/super.c:117 > #1: ffff0000c9d147d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:364 [inline] > #1: ffff0000c9d147d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x208/0x944 fs/fs-writeback.c:2756 > 2 locks held by syz-executor439/7450: > #0: ffff0000c5e920e0 (&type->s_umount_key#64){++++}-{3:3}, at: __super_lock fs/super.c:58 [inline] > #0: ffff0000c5e920e0 (&type->s_umount_key#64){++++}-{3:3}, at: super_lock+0x160/0x328 fs/super.c:117 > #1: ffff0000c9d147d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:364 [inline] > #1: ffff0000c9d147d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x208/0x944 fs/fs-writeback.c:2756 > 2 locks held by syz-executor439/7451: > #0: ffff0000c5e920e0 (&type->s_umount_key#64){++++}-{3:3}, at: __super_lock fs/super.c:58 [inline] > #0: ffff0000c5e920e0 (&type->s_umount_key#64){++++}-{3:3}, at: super_lock+0x160/0x328 fs/super.c:117 > #1: ffff0000c9d147d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:364 [inline] > #1: ffff0000c9d147d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x208/0x944 fs/fs-writeback.c:2756 > 2 locks held by syz-executor439/7460: > #0: ffff0000c5e920e0 (&type->s_umount_key#64){++++}-{3:3}, at: __super_lock fs/super.c:58 [inline] > #0: ffff0000c5e920e0 (&type->s_umount_key#64){++++}-{3:3}, at: super_lock+0x160/0x328 fs/super.c:117 > #1: ffff0000c9d147d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:364 [inline] > #1: ffff0000c9d147d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x208/0x944 fs/fs-writeback.c:2756 > > ============================================= > > > > --- > 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 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 The hang of this report seems to be due to an issue of nilfs2 side. I will fix it. Ryusuke Konishi
