INFO: task syz.8.2505:16467 blocked for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.8.2505 state:D stack:25432 pid:16467 tgid:16455 ppid:12499 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0xfee/0x6120 kernel/sched/core.c:6908 __schedule_loop kernel/sched/core.c:6990 [inline] schedule+0xdd/0x390 kernel/sched/core.c:7005 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7062 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0xc9a/0x1b90 kernel/locking/mutex.c:776 sync_bdevs+0x153/0x480 block/bdev.c:1304 ksys_sync+0xb0/0xf0 fs/sync.c:105 __do_sys_sync+0xe/0x20 fs/sync.c:111 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f83cbf9c799 RSP: 002b:00007f83ccdef028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007f83cc216180 RCX: 00007f83cbf9c799 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f83cc216180 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f83cc216218 R14: 00007f83cc216180 R15: 00007ffedae38918 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e7e75e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8e7e75e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8e7e75e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775 2 locks held by dhcpcd/5473: 2 locks held by getty/5564: #0: ffff8880340f00a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x1500 drivers/tty/n_tty.c:2211 1 lock held by udevd/5796: #0: ffff888027998358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:961 3 locks held by udevd/7671: 1 lock held by syz.8.2505/16467: #0: ffff888027998358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x153/0x480 block/bdev.c:1304 2 locks held by syz.6.2852/17991: 6 locks held by syz.9.2854/18007: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x1d7/0x230 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x141/0x190 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline] watchdog+0xd25/0x1050 kernel/hung_task.c:515 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 18007 Comm: syz.9.2854 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:unwind_next_frame+0x149f/0x1ea0 arch/x86/kernel/unwind_orc.c:663 Code: ff 48 ba 00 00 00 00 00 fc ff df 48 8d 79 02 48 89 f8 48 c1 e8 03 0f b6 34 10 48 8d 41 03 49 89 c0 49 c1 e8 03 41 0f b6 14 10 <49> 89 f8 41 83 e0 07 44 38 c6 41 0f 9e c0 40 84 f6 40 0f 95 c6 41 RSP: 0018:ffffc9000f466638 EFLAGS: 00000a02 RAX: ffffffff91f8b341 RBX: 0000000000000001 RCX: ffffffff91f8b33e RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff91f8b340 RBP: ffffc9000f4666f0 R08: 1ffffffff23f1668 R09: 0000000000000007 R10: 0000000000000200 R11: 00000000000794e2 R12: ffffc9000f4666f8 R13: ffffc9000f4666a8 R14: ffffc9000f4677b0 R15: ffffc9000f4666dc FS: 00007f18c77026c0(0000) GS:ffff888124342000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f5af63456b8 CR3: 00000000ac7a7000 CR4: 00000000003526f0 Call Trace: arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 unpoison_slab_object mm/kasan/common.c:340 [inline] __kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:366 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4538 [inline] slab_alloc_node mm/slub.c:4866 [inline] kmem_cache_alloc_noprof+0x241/0x6e0 mm/slub.c:4873 __kernfs_new_node+0xd2/0x960 fs/kernfs/dir.c:637 kernfs_new_node+0x11b/0x1a0 fs/kernfs/dir.c:718 __kernfs_create_file+0x53/0x350 fs/kernfs/file.c:1057 sysfs_add_file_mode_ns+0x207/0x3c0 fs/sysfs/file.c:313 create_files fs/sysfs/group.c:82 [inline] internal_create_group+0x593/0xf40 fs/sysfs/group.c:189 internal_create_groups+0x9d/0x150 fs/sysfs/group.c:229 setup_gid_attrs drivers/infiniband/core/sysfs.c:1118 [inline] ib_setup_port_attrs+0x41f/0x600 drivers/infiniband/core/sysfs.c:1394 add_one_compat_dev+0x5b3/0x820 drivers/infiniband/core/device.c:977 add_compat_devs drivers/infiniband/core/device.c:1035 [inline] enable_device_and_get+0x33c/0x3f0 drivers/infiniband/core/device.c:1346 ib_register_device drivers/infiniband/core/device.c:1459 [inline] ib_register_device+0x8e6/0xdd0 drivers/infiniband/core/device.c:1405 rxe_register_device+0x277/0x360 drivers/infiniband/sw/rxe/rxe_verbs.c:1556 rxe_net_add+0x95/0xf0 drivers/infiniband/sw/rxe/rxe_net.c:618 rxe_newlink+0x70/0x150 drivers/infiniband/sw/rxe/rxe.c:234 nldev_newlink+0x3ae/0x620 drivers/infiniband/core/nldev.c:1797 rdma_nl_rcv_msg+0x38a/0x6e0 drivers/infiniband/core/netlink.c:195 rdma_nl_rcv_skb.constprop.0.isra.0+0x2cb/0x410 drivers/infiniband/core/netlink.c:239 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x5aa/0x870 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x8b0/0xda0 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] ____sys_sendmsg+0x9e1/0xb70 net/socket.c:2592 ___sys_sendmsg+0x190/0x1e0 net/socket.c:2646 __sys_sendmsg+0x170/0x220 net/socket.c:2678 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f18c679c799 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f18c7702028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f18c6a16180 RCX: 00007f18c679c799 RDX: 0000000000004000 RSI: 0000200000000180 RDI: 0000000000000005 RBP: 00007f18c6832c99 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f18c6a16218 R14: 00007f18c6a16180 R15: 00007ffc58330718