INFO: task syz.0.220:7427 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.220 state:D stack:26392 pid:7427 tgid:7421 ppid:5813 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x16f3/0x4c20 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7307 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1e04/0x25e0 kernel/locking/rtmutex.c:1760 rt_mutex_slowlock+0xb5/0x160 kernel/locking/rtmutex.c:1800 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline] rwbase_write_lock+0x14f/0x750 kernel/locking/rwbase_rt.c:244 inode_lock include/linux/fs.h:979 [inline] open_last_lookups fs/namei.c:3892 [inline] path_openat+0x8e6/0x3840 fs/namei.c:4131 do_filp_open+0x1fa/0x410 fs/namei.c:4161 do_sys_openat2+0x121/0x1c0 fs/open.c:1435 do_sys_open fs/open.c:1450 [inline] __do_sys_openat fs/open.c:1466 [inline] __se_sys_openat fs/open.c:1461 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1461 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f3d3846eec9 RSP: 002b:00007f3d366ad038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f3d386c6090 RCX: 00007f3d3846eec9 RDX: 0000000000000042 RSI: 0000200000000040 RDI: ffffffffffffff9c RBP: 00007f3d384f1f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f3d386c6128 R14: 00007f3d386c6090 R15: 00007fffe1dc1518 INFO: task syz.0.220:7428 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.220 state:D stack:27848 pid:7428 tgid:7421 ppid:5813 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x16f3/0x4c20 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7307 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1e04/0x25e0 kernel/locking/rtmutex.c:1760 rt_mutex_slowlock+0xb5/0x160 kernel/locking/rtmutex.c:1800 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline] rwbase_write_lock+0x14f/0x750 kernel/locking/rwbase_rt.c:244 inode_lock include/linux/fs.h:979 [inline] open_last_lookups fs/namei.c:3892 [inline] path_openat+0x8e6/0x3840 fs/namei.c:4131 do_filp_open+0x1fa/0x410 fs/namei.c:4161 do_sys_openat2+0x121/0x1c0 fs/open.c:1435 do_sys_open fs/open.c:1450 [inline] __do_sys_openat fs/open.c:1466 [inline] __se_sys_openat fs/open.c:1461 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1461 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f3d3846eec9 RSP: 002b:00007f3d3668c038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f3d386c6180 RCX: 00007f3d3846eec9 RDX: 0000000000000042 RSI: 0000200000000040 RDI: ffffffffffffff9c RBP: 00007f3d384f1f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f3d386c6218 R14: 00007f3d386c6180 R15: 00007fffe1dc1518 INFO: task syz.0.220:7429 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.220 state:D stack:27848 pid:7429 tgid:7421 ppid:5813 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x16f3/0x4c20 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7307 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1e04/0x25e0 kernel/locking/rtmutex.c:1760 rt_mutex_slowlock+0xb5/0x160 kernel/locking/rtmutex.c:1800 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline] rwbase_write_lock+0x14f/0x750 kernel/locking/rwbase_rt.c:244 inode_lock include/linux/fs.h:979 [inline] open_last_lookups fs/namei.c:3892 [inline] path_openat+0x8e6/0x3840 fs/namei.c:4131 do_filp_open+0x1fa/0x410 fs/namei.c:4161 do_sys_openat2+0x121/0x1c0 fs/open.c:1435 do_sys_open fs/open.c:1450 [inline] __do_sys_openat fs/open.c:1466 [inline] __se_sys_openat fs/open.c:1461 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1461 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f3d3846eec9 RSP: 002b:00007f3d36269038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f3d386c6270 RCX: 00007f3d3846eec9 RDX: 0000000000000441 RSI: 0000200000000080 RDI: ffffffffffffff9c RBP: 00007f3d384f1f91 R08: 0000000000000000 R09: 0000000000000000 R10: 000000000000014a R11: 0000000000000246 R12: 0000000000000000 R13: 00007f3d386c6308 R14: 00007f3d386c6270 R15: 00007fffe1dc1518 INFO: task syz.0.220:7430 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.220 state:D stack:26936 pid:7430 tgid:7421 ppid:5813 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x16f3/0x4c20 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7307 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1e04/0x25e0 kernel/locking/rtmutex.c:1760 rt_mutex_slowlock+0xb5/0x160 kernel/locking/rtmutex.c:1800 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline] rwbase_write_lock+0x14f/0x750 kernel/locking/rwbase_rt.c:244 inode_lock include/linux/fs.h:979 [inline] open_last_lookups fs/namei.c:3892 [inline] path_openat+0x8e6/0x3840 fs/namei.c:4131 do_filp_open+0x1fa/0x410 fs/namei.c:4161 do_sys_openat2+0x121/0x1c0 fs/open.c:1435 do_sys_open fs/open.c:1450 [inline] __do_sys_openat fs/open.c:1466 [inline] __se_sys_openat fs/open.c:1461 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1461 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f3d3846eec9 RSP: 002b:00007f3d35e46038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f3d386c6360 RCX: 00007f3d3846eec9 RDX: 0000000000000441 RSI: 0000200000000100 RDI: ffffffffffffff9c RBP: 00007f3d384f1f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000105 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f3d386c63f8 R14: 00007f3d386c6360 R15: 00007fffe1dc1518 INFO: task syz.0.220:7431 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.220 state:D stack:27560 pid:7431 tgid:7421 ppid:5813 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x16f3/0x4c20 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7307 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1e04/0x25e0 kernel/locking/rtmutex.c:1760 rt_mutex_slowlock+0xb5/0x160 kernel/locking/rtmutex.c:1800 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline] rwbase_write_lock+0x14f/0x750 kernel/locking/rwbase_rt.c:244 inode_lock include/linux/fs.h:979 [inline] open_last_lookups fs/namei.c:3892 [inline] path_openat+0x8e6/0x3840 fs/namei.c:4131 do_filp_open+0x1fa/0x410 fs/namei.c:4161 do_sys_openat2+0x121/0x1c0 fs/open.c:1435 do_sys_open fs/open.c:1450 [inline] __do_sys_openat fs/open.c:1466 [inline] __se_sys_openat fs/open.c:1461 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1461 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f3d3846eec9 RSP: 002b:00007f3d35a23038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f3d386c6450 RCX: 00007f3d3846eec9 RDX: 000000000000275a RSI: 0000200000000280 RDI: ffffffffffffff9c RBP: 00007f3d384f1f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f3d386c64e8 R14: 00007f3d386c6450 R15: 00007fffe1dc1518 Showing all locks held in the system: 1 lock held by kauditd/37: #0: ffffffff8d3f5778 (kauditd_wait.lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline] #0: ffffffff8d3f5778 (kauditd_wait.lock){+.+.}-{3:3}, at: finish_wait+0xbf/0x1f0 kernel/sched/wait.c:394 1 lock held by khungtaskd/38: #0: ffffffff8d3a9b40 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8d3a9b40 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8d3a9b40 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 4 locks held by kworker/u8:2/43: #0: ffff8881432f9938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff8881432f9938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc90000b47bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc90000b47bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffff888065a7a0d0 (&type->s_umount_key#88){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:563 #3: ffff88803d784628 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:102 3 locks held by kworker/u8:4/69: 4 locks held by kworker/u8:10/1906: 3 locks held by kworker/u8:11/4499: #0: ffff88803028e938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88803028e938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc9000f6c7bc0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc9000f6c7bc0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffffffff8e668c78 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8e668c78 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x119/0x15a0 net/ipv6/addrconf.c:4194 2 locks held by dhcpcd/5475: 2 locks held by getty/5570: #0: ffff88823bf260a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003e832e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x444/0x1400 drivers/tty/n_tty.c:2222 7 locks held by kworker/1:5/5969: 4 locks held by syz.0.220/7422: 2 locks held by syz.0.220/7427: #0: ffff888065a7a488 (sb_writers#24){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:500 #1: ffff88803d7849f8 (&type->i_mutex_dir_key#18){++++}-{4:4}, at: inode_lock include/linux/fs.h:979 [inline] #1: ffff88803d7849f8 (&type->i_mutex_dir_key#18){++++}-{4:4}, at: open_last_lookups fs/namei.c:3892 [inline] #1: ffff88803d7849f8 (&type->i_mutex_dir_key#18){++++}-{4:4}, at: path_openat+0x8e6/0x3840 fs/namei.c:4131 2 locks held by syz.0.220/7428: #0: ffff888065a7a488 (sb_writers#24){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:500 #1: ffff88803d7849f8 (&type->i_mutex_dir_key#18){++++}-{4:4}, at: inode_lock include/linux/fs.h:979 [inline] #1: ffff88803d7849f8 (&type->i_mutex_dir_key#18){++++}-{4:4}, at: open_last_lookups fs/namei.c:3892 [inline] #1: ffff88803d7849f8 (&type->i_mutex_dir_key#18){++++}-{4:4}, at: path_openat+0x8e6/0x3840 fs/namei.c:4131 2 locks held by syz.0.220/7429: #0: ffff888065a7a488 (sb_writers#24){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:500 #1: ffff88803d7849f8 (&type->i_mutex_dir_key#18){++++}-{4:4}, at: inode_lock include/linux/fs.h:979 [inline] #1: ffff88803d7849f8 (&type->i_mutex_dir_key#18){++++}-{4:4}, at: open_last_lookups fs/namei.c:3892 [inline] #1: ffff88803d7849f8 (&type->i_mutex_dir_key#18){++++}-{4:4}, at: path_openat+0x8e6/0x3840 fs/namei.c:4131 2 locks held by syz.0.220/7430: #0: ffff888065a7a488 (sb_writers#24){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:500 #1: ffff88803d7849f8 (&type->i_mutex_dir_key#18){++++}-{4:4}, at: inode_lock include/linux/fs.h:979 [inline] #1: ffff88803d7849f8 (&type->i_mutex_dir_key#18){++++}-{4:4}, at: open_last_lookups fs/namei.c:3892 [inline] #1: ffff88803d7849f8 (&type->i_mutex_dir_key#18){++++}-{4:4}, at: path_openat+0x8e6/0x3840 fs/namei.c:4131 2 locks held by syz.0.220/7431: #0: ffff888065a7a488 (sb_writers#24){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:500 #1: ffff88803d7849f8 (&type->i_mutex_dir_key#18){++++}-{4:4}, at: inode_lock include/linux/fs.h:979 [inline] #1: ffff88803d7849f8 (&type->i_mutex_dir_key#18){++++}-{4:4}, at: open_last_lookups fs/namei.c:3892 [inline] #1: ffff88803d7849f8 (&type->i_mutex_dir_key#18){++++}-{4:4}, at: path_openat+0x8e6/0x3840 fs/namei.c:4131 1 lock held by syz-executor/7710: #0: ffffffff8e668c78 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8e668c78 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff8e668c78 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70 net/core/rtnetlink.c:4056 4 locks held by syz-executor/7764: #0: ffff888034258488 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3101 [inline] #0: ffff888034258488 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x217/0xb40 fs/read_write.c:682 #1: ffff88805e6c0c78 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1df/0x540 fs/kernfs/file.c:343 #2: ffff88814479d4b8 (kn->active#53){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff88814479d4b8 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x540 fs/kernfs/file.c:344 #3: ffffffff8ded82b8 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: new_device_store+0x12c/0x6f0 drivers/net/netdevsim/bus.c:184 7 locks held by syz-executor/7767: #0: ffff888034258488 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3101 [inline] #0: ffff888034258488 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x217/0xb40 fs/read_write.c:682 #1: ffff88805ee3bc78 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1df/0x540 fs/kernfs/file.c:343 #2: ffff88814479d4b8 (kn->active#53){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff88814479d4b8 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x540 fs/kernfs/file.c:344 #3: ffffffff8ded82b8 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: new_device_store+0x12c/0x6f0 drivers/net/netdevsim/bus.c:184 #4: ffff8880320760d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline] #4: ffff8880320760d8 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x400 drivers/base/dd.c:1006 #5: ffff888032072300 (&devlink->lock_key#17){+.+.}-{4:4}, at: nsim_drv_probe+0xc2/0xba0 drivers/net/netdevsim/dev.c:1582 #6: ffffffff8e668c78 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #6: ffffffff8e668c78 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_dev_lock+0x257/0x2f0 net/core/dev.c:2142 4 locks held by syz-executor/7772: #0: ffff888034258488 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3101 [inline] #0: ffff888034258488 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x217/0xb40 fs/read_write.c:682 #1: ffff888023611078 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1df/0x540 fs/kernfs/file.c:343 #2: ffff88814479d4b8 (kn->active#53){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff88814479d4b8 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x540 fs/kernfs/file.c:344 #3: ffffffff8ded82b8 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: new_device_store+0x12c/0x6f0 drivers/net/netdevsim/bus.c:184 2 locks held by syz-executor/7817: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline] watchdog+0xf93/0xfe0 kernel/hung_task.c:491 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x439/0x7d0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 1906 Comm: kworker/u8:10 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Workqueue: bat_events batadv_nc_worker RIP: 0010:__rcu_read_lock+0x39/0x60 kernel/rcu/tree_plugin.h:420 Code: 81 c3 84 04 00 00 48 89 d8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 0f b6 04 08 84 c0 75 18 ff 03 8b 03 3d 00 00 00 40 7d 07 <5b> c3 cc cc cc cc cc 90 0f 0b 90 eb f3 89 d9 80 e1 07 80 c1 03 38 RSP: 0018:ffffc90006227810 EFLAGS: 00000283 RAX: 0000000000000001 RBX: ffff888028585e84 RCX: dffffc0000000000 RDX: ffff8880b893bb60 RSI: ffffffff8cd9167c RDI: 00000000ffffffff RBP: ffffc90006227938 R08: 0000000000000000 R09: ffffffff818365a1 R10: dffffc0000000000 R11: fffffbfff1d6d2a7 R12: ffff888028585e80 R13: dffffc0000000000 R14: ffff88802858654c R15: 1ffff110050b0ca9 FS: 0000000000000000(0000) GS:ffff888127117000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ff3157e7d60 CR3: 000000002471a000 CR4: 00000000003526f0 Call Trace: rcu_read_lock include/linux/rcupdate.h:839 [inline] __local_bh_disable_ip+0x2dc/0x540 kernel/softirq.c:174 local_bh_disable include/linux/bottom_half.h:20 [inline] spin_lock_bh include/linux/spinlock_rt.h:87 [inline] batadv_nc_purge_paths+0xf7/0x3f0 net/batman-adv/network-coding.c:442 batadv_nc_worker+0x87e/0xbc0 net/batman-adv/network-coding.c:720 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x439/0x7d0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245