INFO: task syz.0.1621:12482 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.0.1621 state:D stack:25624 pid:12482 tgid:12481 ppid:5817 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x1139/0x6150 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6960 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7017 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0xc69/0x1ca0 kernel/locking/mutex.c:776 sync_bdevs+0x153/0x480 block/bdev.c:1305 ksys_sync+0xb2/0x150 fs/sync.c:105 __do_sys_sync+0xe/0x20 fs/sync.c:113 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fc9f158f749 RSP: 002b:00007fc9f2418038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007fc9f17e5fa0 RCX: 00007fc9f158f749 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007fc9f17e5fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fc9f17e6038 R14: 00007fc9f17e5fa0 R15: 00007ffcfa63dc38 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e3c96a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e3c96a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8e3c96a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775 2 locks held by getty/5576: #0: ffff888036b850a0 (&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+0x41b/0x1510 drivers/tty/n_tty.c:2211 1 lock held by syz-executor/5800: #0: ffff8880b843ac98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:647 [inline] #0: ffff8880b843ac98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x7e/0x130 kernel/sched/core.c:632 1 lock held by udevd/5819: #0: ffff8880264be358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:962 1 lock held by udevd/6114: #0: ffff88802655b358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:962 1 lock held by syz.0.1621/12482: #0: ffff88802655b358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x153/0x480 block/bdev.c:1305 1 lock held by syz.1.1979/13875: #0: ffff88802655b358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x153/0x480 block/bdev.c:1305 6 locks held by syz.7.2161/14640: 1 lock held by syz.8.2168/14659: ============================================= NMI backtrace for cpu 0 CPU: 0 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 10/25/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x133/0x180 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline] watchdog+0xe66/0x1180 kernel/hung_task.c:515 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 14640 Comm: syz.7.2161 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:__this_cpu_preempt_check+0x0/0x20 lib/smp_processor_id.c:63 Code: c6 80 b3 f2 8b 48 c7 c7 c0 b3 f2 8b e9 f9 fe ff ff 66 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 48 89 fe 48 c7 c7 00 b4 f2 8b e9 cd fe ff ff 66 2e 0f RSP: 0018:ffffc90003956418 EFLAGS: 00000006 RAX: 0000000000000000 RBX: ffffffff8e3c96a0 RCX: ffffc90003958001 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8dbbe5ad RBP: 0000000000000001 R08: 0000000000000001 R09: 000000008ce0c730 R10: 0000000000000002 R11: 0000000000079599 R12: ffffffff816cb9a4 R13: 0000000000000206 R14: ffff888026d6a4c0 R15: ffffc9000395650c FS: 00007f3012c546c0(0000) GS:ffff8881249f5000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fff442cc000 CR3: 000000002c63d000 CR4: 00000000003526f0 Call Trace: lockdep_recursion_inc kernel/locking/lockdep.c:465 [inline] lock_release+0x9c/0x2d0 kernel/locking/lockdep.c:5888 rcu_lock_release include/linux/rcupdate.h:341 [inline] rcu_read_unlock include/linux/rcupdate.h:897 [inline] class_rcu_destructor include/linux/rcupdate.h:1195 [inline] unwind_next_frame+0x3f9/0x20b0 arch/x86/kernel/unwind_orc.c:495 arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x33/0x60 mm/kasan/common.c:56 kasan_save_track+0x14/0x30 mm/kasan/common.c:77 poison_kmalloc_redzone mm/kasan/common.c:397 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:414 kasan_kmalloc include/linux/kasan.h:262 [inline] __do_kmalloc_node mm/slub.c:5657 [inline] __kmalloc_node_track_caller_noprof+0x353/0x930 mm/slub.c:5764 __kmemdup_nul mm/util.c:64 [inline] kstrdup+0x53/0x100 mm/util.c:84 kstrdup_const+0x63/0x80 mm/util.c:104 __kernfs_new_node+0x9b/0x990 fs/kernfs/dir.c:633 kernfs_new_node+0x13c/0x1e0 fs/kernfs/dir.c:716 __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+0x597/0xf70 fs/sysfs/group.c:189 internal_create_groups+0x9d/0x150 fs/sysfs/group.c:229 setup_port+0x409/0x1720 drivers/infiniband/core/sysfs.c:1247 ib_setup_port_attrs+0x201/0x600 drivers/infiniband/core/sysfs.c:1433 add_one_compat_dev+0x5b3/0x820 drivers/infiniband/core/device.c:1005 add_compat_devs drivers/infiniband/core/device.c:1063 [inline] enable_device_and_get+0x336/0x3f0 drivers/infiniband/core/device.c:1374 ib_register_device drivers/infiniband/core/device.c:1487 [inline] ib_register_device+0x8de/0xe70 drivers/infiniband/core/device.c:1433 rxe_register_device+0x277/0x340 drivers/infiniband/sw/rxe/rxe_verbs.c:1556 rxe_net_add+0x95/0xf0 drivers/infiniband/sw/rxe/rxe_net.c:586 rxe_newlink+0x70/0x190 drivers/infiniband/sw/rxe/rxe.c:234 nldev_newlink+0x3a6/0x680 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+0x2d0/0x430 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+0x8c8/0xdd0 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] ____sys_sendmsg+0xa5d/0xc30 net/socket.c:2592 ___sys_sendmsg+0x134/0x1d0 net/socket.c:2646 __sys_sendmsg+0x16d/0x220 net/socket.c:2678 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f3011d8f749 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f3012c54038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f3011fe6090 RCX: 00007f3011d8f749 RDX: 0000000000008844 RSI: 0000200000000080 RDI: 0000000000000006 RBP: 00007f3011e13f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f3011fe6128 R14: 00007f3011fe6090 R15: 00007ffd6265adc8