INFO: task syz.0.19:5257 blocked for more than 143 seconds. Not tainted 5.15.180-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.19 state:D stack:25440 pid: 5257 ppid: 5102 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5030 [inline] __schedule+0x12c4/0x45b0 kernel/sched/core.c:6376 schedule+0x11b/0x1f0 kernel/sched/core.c:6459 schedule_timeout+0xac/0x300 kernel/time/timer.c:1890 do_wait_for_common+0x2d9/0x480 kernel/sched/completion.c:85 __wait_for_common kernel/sched/completion.c:106 [inline] wait_for_common kernel/sched/completion.c:117 [inline] wait_for_completion+0x48/0x60 kernel/sched/completion.c:138 kthread_stop+0x178/0x580 kernel/kthread.c:666 ext4_stop_mmpd+0x43/0xb0 fs/ext4/mmp.c:263 ext4_fill_super+0x6d67/0xa110 fs/ext4/super.c:5089 mount_bdev+0x2c9/0x3f0 fs/super.c:1400 legacy_get_tree+0xeb/0x180 fs/fs_context.c:611 vfs_get_tree+0x88/0x270 fs/super.c:1530 do_new_mount+0x2ba/0xb40 fs/namespace.c:3012 do_mount fs/namespace.c:3355 [inline] __do_sys_mount fs/namespace.c:3563 [inline] __se_sys_mount+0x2d5/0x3c0 fs/namespace.c:3540 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0x80 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f36783ab90a RSP: 002b:00007f367761ae68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f367761aef0 RCX: 00007f36783ab90a RDX: 0000400000000040 RSI: 0000400000000000 RDI: 00007f367761aeb0 RBP: 0000400000000040 R08: 00007f367761aef0 R09: 0000000003010008 R10: 0000000003010008 R11: 0000000000000246 R12: 0000400000000000 R13: 00007f367761aeb0 R14: 0000000000000538 R15: 0000400000000340 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8cb1f4e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 1 lock held by udevd/3546: 2 locks held by getty/3921: #0: ffff88814c758098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc90002cd62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6af/0x1db0 drivers/tty/n_tty.c:2158 2 locks held by kworker/1:6/4261: 3 locks held by kworker/0:7/4300: #0: ffff888017470938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283 #1: ffffc90002e3fd20 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285 #2: ffff88807e6a6240 (&data->fib_lock){+.+.}-{3:3}, at: nsim_fib_event_work+0x2cd/0x4120 drivers/net/netdevsim/fib.c:1480 2 locks held by kworker/1:19/5116: #0: ffff888017472138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283 #1: ffffc900031ffd20 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285 1 lock held by syz.0.19/5257: #0: ffff888021ad60e0 (&type->s_umount_key#28/1){+.+.}-{3:3}, at: alloc_super+0x210/0x940 fs/super.c:229 1 lock held by syz.1.39/5403: #0: ffff88801c1b60e0 (&type->s_umount_key#28/1){+.+.}-{3:3}, at: alloc_super+0x210/0x940 fs/super.c:229 1 lock held by syz.2.64/5493: #0: ffff888075e580e0 (&type->s_umount_key#28/1){+.+.}-{3:3}, at: alloc_super+0x210/0x940 fs/super.c:229 1 lock held by syz.3.65/5509: #0: ffff888078e580e0 (&type->s_umount_key#28/1){+.+.}-{3:3}, at: alloc_super+0x210/0x940 fs/super.c:229 1 lock held by syz.4.79/5570: #0: ffff88802405e0e0 (&type->s_umount_key#28/1){+.+.}-{3:3}, at: alloc_super+0x210/0x940 fs/super.c:229 1 lock held by syz.5.82/5600: #0: ffff88814be220e0 (&type->s_umount_key#28/1){+.+.}-{3:3}, at: alloc_super+0x210/0x940 fs/super.c:229 1 lock held by syz.6.85/5634: #0: ffff8880617e40e0 (&type->s_umount_key#28/1){+.+.}-{3:3}, at: alloc_super+0x210/0x940 fs/super.c:229 1 lock held by syz.7.90/5668: #0: ffff88807dd200e0 (&type->s_umount_key#28/1){+.+.}-{3:3}, at: alloc_super+0x210/0x940 fs/super.c:229 1 lock held by syz-executor/5671: #0: ffff88802175b918 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x14d/0xa50 block/bdev.c:820 2 locks held by udevd/5675: #0: ffff88802175b918 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0xfb/0x790 block/bdev.c:915 #1: ffff88802185d468 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0xa9/0xbe0 drivers/block/loop.c:1365 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 27 Comm: khungtaskd Not tainted 5.15.180-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106 nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline] watchdog+0xe72/0xeb0 kernel/hung_task.c:369 kthread+0x3f6/0x4f0 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 154 Comm: kworker/u4:2 Not tainted 5.15.180-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Workqueue: bat_events batadv_nc_worker RIP: 0010:check_kcov_mode kernel/kcov.c:174 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x2c/0x60 kernel/kcov.c:206 Code: 04 24 65 48 8b 0d 74 2d 82 7e 65 8b 15 75 2d 82 7e 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 34 16 00 00 00 74 2c <8b> 91 10 16 00 00 83 fa 02 75 21 48 8b 91 18 16 00 00 48 8b 32 48 RSP: 0018:ffffc90001fe7bf0 EFLAGS: 00000246 RAX: ffffffff8a1bfa7a RBX: 0000000000000001 RCX: ffff88801d559dc0 RDX: 0000000000000000 RSI: ffffffff8aab2b80 RDI: ffffffff8af9e940 RBP: 0000000000000001 R08: dffffc0000000000 R09: fffffbfff1c154b6 R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000394 R13: dffffc0000000000 R14: ffff888079cb0c80 R15: ffff888143b9d180 FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c008816000 CR3: 000000007e119000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:409 [inline] batadv_nc_worker+0x25a/0x5b0 net/batman-adv/network-coding.c:723 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457 kthread+0x3f6/0x4f0 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287