INFO: task syz.3.4:5898 blocked for more than 143 seconds. Not tainted 6.15.0-rc4-syzkaller-00319-g14c55b7bb0a8 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.4 state:D stack:19848 pid:5898 tgid:5897 ppid:5827 task_flags:0x400140 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x168f/0x4c70 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0x165/0x360 kernel/sched/core.c:6860 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6917 rwsem_down_write_slowpath+0xbec/0x1030 kernel/locking/rwsem.c:1176 __down_write_common kernel/locking/rwsem.c:1304 [inline] __down_write kernel/locking/rwsem.c:1313 [inline] down_write+0x1ab/0x1f0 kernel/locking/rwsem.c:1578 inode_lock include/linux/fs.h:867 [inline] open_last_lookups fs/namei.c:3797 [inline] path_openat+0x8da/0x3830 fs/namei.c:4036 do_filp_open+0x1fa/0x410 fs/namei.c:4066 do_sys_openat2+0x121/0x1c0 fs/open.c:1429 do_sys_open fs/open.c:1444 [inline] __do_sys_openat fs/open.c:1460 [inline] __se_sys_openat fs/open.c:1455 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1455 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f6a0218e969 RSP: 002b:00007f6a0306e038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f6a023b5fa0 RCX: 00007f6a0218e969 RDX: 0000000000101042 RSI: 00002000000000c0 RDI: ffffffffffffff9c RBP: 00007f6a02210ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000004 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f6a023b5fa0 R15: 00007fffc4c9baa8 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6764 5 locks held by kworker/u8:5/1097: 2 locks held by getty/5573: #0: ffff8880301ec0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900036db2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 3 locks held by kworker/0:3/5821: #0: ffff8880b88399d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:605 #1: ffff8880b8823b08 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x39e/0x6d0 kernel/sched/psi.c:987 #2: ffff88804c09a538 (&idev->mc_lock){+.+.}-{4:4}, at: mld_dad_work+0x3d/0x520 net/ipv6/mcast.c:2307 2 locks held by syz.3.4/5898: #0: ffff88805cf40420 (sb_writers#13){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:556 #1: ffff88805f550148 (&sb->s_type->i_mutex_key#22){++++}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline] #1: ffff88805f550148 (&sb->s_type->i_mutex_key#22){++++}-{4:4}, at: open_last_lookups fs/namei.c:3797 [inline] #1: ffff88805f550148 (&sb->s_type->i_mutex_key#22){++++}-{4:4}, at: path_openat+0x8da/0x3830 fs/namei.c:4036 4 locks held by syz.3.4/5929: #0: ffff88805cf40420 (sb_writers#13){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:556 #1: ffff88805f550148 (&sb->s_type->i_mutex_key#22/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:902 [inline] #1: ffff88805f550148 (&sb->s_type->i_mutex_key#22/1){+.+.}-{4:4}, at: filename_create+0x1f9/0x470 fs/namei.c:4132 #2: ffff88805cc84228 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:161 [inline] #2: ffff88805cc84228 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:253 [inline] #2: ffff88805cc84228 (&c->btree_trans_barrier){.+.+}-{0:0}, at: bch2_trans_srcu_lock+0xaf/0x220 fs/bcachefs/btree_iter.c:3202 #3: ffff88805cca6590 (&c->gc_lock){++++}-{4:4}, at: bch2_btree_update_start+0x68f/0x14c0 fs/bcachefs/btree_update_interior.c:1179 2 locks held by bch-copygc/loop/5918: 3 locks held by kworker/u8:11/6659: #0: ffff88814cd3f148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88814cd3f148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319 #1: ffffc90003d5fc60 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc90003d5fc60 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319 #2: ffffffff8f2e2588 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8f2e2588 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x112/0x14b0 net/ipv6/addrconf.c:4195 6 locks held by syz-executor/7262: #0: ffff88807dd6e420 (sb_writers#9){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3041 [inline] #0: ffff88807dd6e420 (sb_writers#9){.+.+}-{0:0}, at: vfs_write+0x211/0xa90 fs/read_write.c:680 #1: ffff888023b5fc88 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1e0/0x4f0 fs/kernfs/file.c:325 #2: ffffffff8df72988 (cgroup_mutex){+.+.}-{4:4}, at: cgroup_lock include/linux/cgroup.h:369 [inline] #2: ffffffff8df72988 (cgroup_mutex){+.+.}-{4:4}, at: cgroup_kn_lock_live+0x13c/0x230 kernel/cgroup/cgroup.c:1675 #3: ffffffff8ddd4490 (cpu_hotplug_lock){++++}-{0:0}, at: cgroup_attach_lock kernel/cgroup/cgroup.c:2478 [inline] #3: ffffffff8ddd4490 (cpu_hotplug_lock){++++}-{0:0}, at: cgroup_procs_write_start+0x186/0x600 kernel/cgroup/cgroup.c:2982 #4: ffffffff8df72b70 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: cgroup_attach_lock kernel/cgroup/cgroup.c:2480 [inline] #4: ffffffff8df72b70 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: cgroup_procs_write_start+0x19c/0x600 kernel/cgroup/cgroup.c:2982 #5: ffffffff8df41338 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:304 [inline] #5: ffffffff8df41338 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f4/0x730 kernel/rcu/tree_exp.h:998 3 locks held by syz-executor/7286: #0: ffffffff8f2e2588 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8f2e2588 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff8f2e2588 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70 net/core/rtnetlink.c:4064 #1: ffff888061de14e8 (&wg->device_update_lock){+.+.}-{4:4}, at: wg_open+0x227/0x420 drivers/net/wireguard/device.c:50 #2: ffffffff8df41338 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline] #2: ffffffff8df41338 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b7/0x730 kernel/rcu/tree_exp.h:998 1 lock held by syz-executor/7521: #0: ffffffff8f2e2588 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8f2e2588 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0 net/ipv4/devinet.c:979 1 lock held by syz-executor/7617: #0: ffffffff8f2e2588 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8f2e2588 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0 net/ipv4/devinet.c:979 1 lock held by dhcpcd-run-hook/7801: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc4-syzkaller-00319-g14c55b7bb0a8 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/29/2025 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:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:274 [inline] watchdog+0xfee/0x1030 kernel/hung_task.c:437 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 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: 5805 Comm: syz-executor Not tainted 6.15.0-rc4-syzkaller-00319-g14c55b7bb0a8 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/29/2025 RIP: 0010:lock_acquire+0x175/0x360 kernel/locking/lockdep.c:5870 Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 4b 12 d4 10 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e RSP: 0018:ffffc90000a07b98 EFLAGS: 00000206 RAX: 6e9ff60716765300 RBX: 0000000000000000 RCX: 6e9ff60716765300 RDX: 0000000000000000 RSI: ffffffff8d92127c RDI: ffffffff8bc0fea0 RBP: ffffffff8171a9f5 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: ffffffff8171a9f5 R12: 0000000000000002 R13: ffffffff8df3b860 R14: 0000000000000000 R15: 0000000000000246 FS: 00005555899db500(0000) GS:ffff8881261fd000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f4244fccba8 CR3: 0000000059796000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] class_rcu_constructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0xc2/0x2390 arch/x86/kernel/unwind_orc.c:479 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack+0x3e/0x60 mm/kasan/common.c:47 kasan_record_aux_stack+0xbc/0xd0 mm/kasan/generic.c:548 kvfree_call_rcu+0xbb/0x410 mm/slab_common.c:1962 cfg80211_update_known_bss+0x634/0x1330 net/wireless/scan.c:1925 __cfg80211_bss_update+0x147/0x2120 net/wireless/scan.c:1972 cfg80211_inform_single_bss_data+0xba9/0x1ac0 net/wireless/scan.c:2363 cfg80211_inform_bss_data+0x1f6/0x3ad0 net/wireless/scan.c:3222 cfg80211_inform_bss_frame_data+0x362/0x700 net/wireless/scan.c:3317 ieee80211_bss_info_update+0x746/0x9e0 net/mac80211/scan.c:226 ieee80211_scan_rx+0x527/0x9b0 net/mac80211/scan.c:340 __ieee80211_rx_handle_packet net/mac80211/rx.c:5179 [inline] ieee80211_rx_list+0x22fc/0x2d80 net/mac80211/rx.c:5416 ieee80211_rx_napi+0x1a8/0x3d0 net/mac80211/rx.c:5439 ieee80211_rx include/net/mac80211.h:5179 [inline] ieee80211_handle_queued_frames+0xe8/0x1f0 net/mac80211/main.c:441 tasklet_action_common+0x369/0x580 kernel/softirq.c:829 handle_softirqs+0x283/0x870 kernel/softirq.c:579 do_softirq+0xec/0x180 kernel/softirq.c:480 __local_bh_enable_ip+0x17d/0x1c0 kernel/softirq.c:407 lock_sock include/net/sock.h:1651 [inline] tcp_recvmsg+0x1fa/0x810 net/ipv4/tcp.c:2877 inet_recvmsg+0x147/0x250 net/ipv4/af_inet.c:883 sock_recvmsg_nosec net/socket.c:1017 [inline] sock_recvmsg+0x1a8/0x270 net/socket.c:1039 sock_read_iter+0x231/0x2f0 net/socket.c:1109 new_sync_read fs/read_write.c:489 [inline] vfs_read+0x4cd/0x980 fs/read_write.c:570 ksys_read+0x145/0x250 fs/read_write.c:713 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fbf2478d33d Code: a8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff eb b5 e8 a8 48 00 00 0f 1f 84 00 00 00 00 00 80 3d 01 72 1f 00 00 74 17 31 c0 0f 05 <48> 3d 00 f0 ff ff 77 5b c3 66 2e 0f 1f 84 00 00 00 00 00 48 83 ec RSP: 002b:00007fff01c251d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fbf2478d33d RDX: 0000000000000004 RSI: 00007fff01c251ec RDI: 0000000000000003 RBP: 0000000000000000 R08: 000000002dc56396 R09: 7fffffffffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 00007fff01c25600 R13: 0000000000000004 R14: 00007fff01c251ec R15: 00007fff01c25280