Hello, syzbot found the following issue on: HEAD commit: 2014c95afece Linux 6.14-rc1 git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=1131c3df980000 kernel config: https://syzkaller.appspot.com/x/.config?x=19886416c83671c4 dashboard link: https://syzkaller.appspot.com/bug?extid=038e767da0db0a0d9b59 compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=11b1d724580000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1531c3df980000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/829b24bcce21/disk-2014c95a.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/6fe35dde263a/vmlinux-2014c95a.xz kernel image: https://storage.googleapis.com/syzbot-assets/aeece1d48196/bzImage-2014c95a.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+038e767da0db0a0d9b59@xxxxxxxxxxxxxxxxxxxxxxxxx INFO: task syz-executor278:10447 blocked for more than 143 seconds. Not tainted 6.14.0-rc1-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor278 state:D stack:25912 pid:10447 tgid:10445 ppid:5838 task_flags:0x400040 flags:0x00004006 Call Trace: <TASK> context_switch kernel/sched/core.c:5377 [inline] __schedule+0x190e/0x4c90 kernel/sched/core.c:6764 __schedule_loop kernel/sched/core.c:6841 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6856 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6913 rwsem_down_read_slowpath kernel/locking/rwsem.c:1084 [inline] __down_read_common kernel/locking/rwsem.c:1248 [inline] __down_read kernel/locking/rwsem.c:1261 [inline] down_read+0x705/0xa40 kernel/locking/rwsem.c:1526 i_mmap_lock_read include/linux/fs.h:565 [inline] rmap_walk_file+0x69c/0x780 mm/rmap.c:2694 remove_migration_ptes mm/migrate.c:365 [inline] unmap_and_move_huge_page mm/migrate.c:1518 [inline] migrate_hugetlbs mm/migrate.c:1640 [inline] migrate_pages+0xd34/0x34a0 mm/migrate.c:2070 do_mbind mm/mempolicy.c:1394 [inline] kernel_mbind mm/mempolicy.c:1537 [inline] __do_sys_mbind mm/mempolicy.c:1611 [inline] __se_sys_mbind+0x14b8/0x1980 mm/mempolicy.c:1607 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fc308171e89 RSP: 002b:00007fc308120168 EFLAGS: 00000246 ORIG_RAX: 00000000000000ed RAX: ffffffffffffffda RBX: 00007fc3081f63e8 RCX: 00007fc308171e89 RDX: 0000000000000000 RSI: 0000000000800000 RDI: 0000000020001000 RBP: 00007fc3081f63e0 R08: 0000000000000040 R09: 0000000000000002 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fc3081f63ec R13: 0000000000000016 R14: 00007ffc9e93b110 R15: 00007ffc9e93b1f8 </TASK> INFO: task syz-executor278:10464 blocked for more than 143 seconds. Not tainted 6.14.0-rc1-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor278 state:D stack:25688 pid:10464 tgid:10445 ppid:5838 task_flags:0x400040 flags:0x00004006 Call Trace: <TASK> context_switch kernel/sched/core.c:5377 [inline] __schedule+0x190e/0x4c90 kernel/sched/core.c:6764 __schedule_loop kernel/sched/core.c:6841 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6856 io_schedule+0x8d/0x110 kernel/sched/core.c:7689 folio_wait_bit_common+0x839/0xee0 mm/filemap.c:1318 __folio_lock mm/filemap.c:1665 [inline] folio_lock include/linux/pagemap.h:1163 [inline] __filemap_get_folio+0x14e/0xae0 mm/filemap.c:1918 filemap_lock_folio include/linux/pagemap.h:800 [inline] filemap_lock_hugetlb_folio include/linux/hugetlb.h:790 [inline] hugetlbfs_zero_partial_page+0xb0/0x590 fs/hugetlbfs/inode.c:656 hugetlbfs_punch_hole fs/hugetlbfs/inode.c:710 [inline] hugetlbfs_fallocate+0xbd2/0x11a0 fs/hugetlbfs/inode.c:743 vfs_fallocate+0x623/0x7a0 fs/open.c:338 madvise_remove mm/madvise.c:1025 [inline] madvise_vma_behavior mm/madvise.c:1260 [inline] madvise_walk_vmas mm/madvise.c:1502 [inline] do_madvise+0x23c9/0x4d90 mm/madvise.c:1689 __do_sys_madvise mm/madvise.c:1705 [inline] __se_sys_madvise mm/madvise.c:1703 [inline] __x64_sys_madvise+0xa6/0xc0 mm/madvise.c:1703 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fc308171e89 RSP: 002b:00007fc3080ff178 EFLAGS: 00000246 ORIG_RAX: 000000000000001c RAX: ffffffffffffffda RBX: 00007fc3081f63f8 RCX: 00007fc308171e89 RDX: 0000000000000009 RSI: 0000000000600002 RDI: 0000000020000000 RBP: 00007fc3081f63f0 R08: 00007ffc9e93b1f7 R09: 00007fc3080ff6c0 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fc3081f63fc R13: 000000000000006e R14: 00007ffc9e93b110 R15: 00007ffc9e93b1f8 </TASK> Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff8e9387e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e9387e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e9387e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6746 5 locks held by kworker/u8:8/3011: 2 locks held by getty/5593: #0: ffff88803570a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90002fde2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x6a6/0x1e00 drivers/tty/n_tty.c:2211 1 lock held by syz-executor278/10447: #0: ffff88801f749d68 (&hugetlbfs_i_mmap_rwsem_key){++++}-{4:4}, at: i_mmap_lock_read include/linux/fs.h:565 [inline] #0: ffff88801f749d68 (&hugetlbfs_i_mmap_rwsem_key){++++}-{4:4}, at: rmap_walk_file+0x69c/0x780 mm/rmap.c:2694 3 locks held by syz-executor278/10464: #0: ffff888021aa4420 (sb_writers#9){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3023 [inline] #0: ffff888021aa4420 (sb_writers#9){.+.+}-{0:0}, at: vfs_fallocate+0x59d/0x7a0 fs/open.c:337 #1: ffff88801f749a98 (&sb->s_type->i_mutex_key#16){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:865 [inline] #1: ffff88801f749a98 (&sb->s_type->i_mutex_key#16){+.+.}-{4:4}, at: hugetlbfs_punch_hole fs/hugetlbfs/inode.c:685 [inline] #1: ffff88801f749a98 (&sb->s_type->i_mutex_key#16){+.+.}-{4:4}, at: hugetlbfs_fallocate+0x408/0x11a0 fs/hugetlbfs/inode.c:743 #2: ffff88801f749d68 (&hugetlbfs_i_mmap_rwsem_key){++++}-{4:4}, at: i_mmap_lock_write include/linux/fs.h:545 [inline] #2: ffff88801f749d68 (&hugetlbfs_i_mmap_rwsem_key){++++}-{4:4}, at: hugetlbfs_punch_hole fs/hugetlbfs/inode.c:693 [inline] #2: ffff88801f749d68 (&hugetlbfs_i_mmap_rwsem_key){++++}-{4:4}, at: hugetlbfs_fallocate+0x4ce/0x11a0 fs/hugetlbfs/inode.c:743 1 lock held by syz-executor278/3275: #0: ffffffff8e93dcb8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:334 [inline] #0: ffffffff8e93dcb8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x451/0x830 kernel/rcu/tree_exp.h:996 1 lock held by syz-executor278/3284: #0: ffffffff8e93dcb8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:334 [inline] #0: ffffffff8e93dcb8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x451/0x830 kernel/rcu/tree_exp.h:996 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.14.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 Call Trace: <TASK> __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:236 [inline] watchdog+0x1058/0x10a0 kernel/hung_task.c:399 kthread+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 </TASK> Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 2974 Comm: kworker/u8:6 Not tainted 6.14.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 Workqueue: events_unbound nsim_dev_trap_report_work RIP: 0010:rcu_is_watching+0x70/0xb0 kernel/rcu/tree.c:718 Code: c3 58 79 03 00 49 03 1e 48 89 d8 48 c1 e8 03 42 0f b6 04 38 84 c0 75 22 8b 03 65 ff 0d 01 bb 5e 7e 74 10 83 e0 04 c1 e8 02 5b <41> 5e 41 5f c3 cc cc cc cc e8 f2 1c 85 ff eb e9 89 d9 80 e1 07 80 RSP: 0018:ffffc9000c1877b0 EFLAGS: 00000002 RAX: 0000000000000001 RBX: 0000000000000001 RCX: ffffffff81c720ac RDX: 0000000000000000 RSI: ffffffff8c608960 RDI: ffffffff8c608920 RBP: ffffc9000c187870 R08: ffffffff901b5177 R09: 1ffffffff2036a2e R10: dffffc0000000000 R11: fffffbfff2036a2f R12: 0000000000000246 R13: 1ffff92001830efc R14: ffffffff8e313b58 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc3080ffd58 CR3: 00000000122f4000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <NMI> </NMI> <TASK> trace_irq_disable+0x3b/0x120 include/trace/events/preemptirq.h:36 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:108 [inline] _raw_spin_lock_irqsave+0xb0/0x120 kernel/locking/spinlock.c:162 __debug_check_no_obj_freed lib/debugobjects.c:1088 [inline] debug_check_no_obj_freed+0x234/0x580 lib/debugobjects.c:1129 slab_free_hook mm/slub.c:2284 [inline] slab_free mm/slub.c:4609 [inline] kmem_cache_free+0x114/0x410 mm/slub.c:4711 nsim_dev_trap_report drivers/net/netdevsim/dev.c:821 [inline] nsim_dev_trap_report_work+0x7cc/0xb50 drivers/net/netdevsim/dev.c:851 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3317 worker_thread+0x870/0xd30 kernel/workqueue.c:3398 kthread+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 </TASK> INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.311 msecs --- 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
