INFO: task syz.4.4694:15753 blocked for more than 143 seconds. Not tainted 6.14.0-rc4-syzkaller-00278-gece144f151ac #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.4694 state:D stack:28416 pid:15753 tgid:15747 ppid:6285 task_flags:0x400040 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5378 [inline] __schedule+0xf43/0x5890 kernel/sched/core.c:6765 __schedule_loop kernel/sched/core.c:6842 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6857 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6914 __mutex_lock_common kernel/locking/mutex.c:662 [inline] __mutex_lock+0x6bd/0xb10 kernel/locking/mutex.c:730 ptmx_open drivers/tty/pty.c:823 [inline] ptmx_open+0xff/0x360 drivers/tty/pty.c:790 chrdev_open+0x237/0x6a0 fs/char_dev.c:414 do_dentry_open+0x735/0x1c40 fs/open.c:956 vfs_open+0x82/0x3f0 fs/open.c:1086 do_open fs/namei.c:3830 [inline] path_openat+0x1e88/0x2d80 fs/namei.c:3989 do_filp_open+0x20c/0x470 fs/namei.c:4016 do_sys_openat2+0x17a/0x1e0 fs/open.c:1428 do_sys_open fs/open.c:1443 [inline] __do_sys_openat fs/open.c:1459 [inline] __se_sys_openat fs/open.c:1454 [inline] __x64_sys_openat+0x175/0x210 fs/open.c:1454 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7faabed8d169 RSP: 002b:00007faabfc88038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007faabefa5fa0 RCX: 00007faabed8d169 RDX: 0000000000000800 RSI: 0000400000000100 RDI: ffffffffffffff9c RBP: 00007faabee0e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007faabefa5fa0 R15: 00007fff8166e808 Showing all locks held in the system: 3 locks held by kworker/u8:1/12: 1 lock held by khungtaskd/30: #0: ffffffff8e1bccc0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e1bccc0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e1bccc0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x7f/0x390 kernel/locking/lockdep.c:6746 3 locks held by kworker/u8:2/35: 3 locks held by kworker/u8:3/58: 1 lock held by kswapd0/89: 2 locks held by kworker/0:2/865: 3 locks held by kworker/u8:5/1156: 3 locks held by syslogd/5173: 2 locks held by udevd/5191: 2 locks held by dhcpcd/5484: 2 locks held by getty/5571: #0: ffff88814d3c20a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc90002fde2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0xfba/0x1480 drivers/tty/n_tty.c:2211 3 locks held by kworker/1:3/6268: 2 locks held by syz-executor/6270: 1 lock held by syz-executor/6277: 4 locks held by syz-executor/6282: 3 locks held by syz-executor/6288: 3 locks held by kworker/1:7/6421: #0: ffff88801b078d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3213 #1: ffffc90004067d18 (deferred_process_work){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3214 #2: ffffffff8fef7528 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104 1 lock held by syz.4.4694/15753: #0: ffffffff8ee87ee8 (tty_mutex){+.+.}-{4:4}, at: ptmx_open drivers/tty/pty.c:823 [inline] #0: ffffffff8ee87ee8 (tty_mutex){+.+.}-{4:4}, at: ptmx_open+0xff/0x360 drivers/tty/pty.c:790 2 locks held by syz-executor/15756: #0: ffffffff8fef7528 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:698 [inline] #0: ffffffff8fef7528 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x38/0x230 drivers/net/tun.c:3517 #1: ffffffff8e1c8138 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x1a4/0x3b0 kernel/rcu/tree_exp.h:334 3 locks held by kworker/u8:9/15757: 2 locks held by kworker/1:1/15761: 2 locks held by syz-executor/15762: 3 locks held by kworker/u8:10/15763: 3 locks held by kworker/0:8/15764: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.14.0-rc4-syzkaller-00278-gece144f151ac #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 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:162 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:236 [inline] watchdog+0xf62/0x12b0 kernel/hung_task.c:399 kthread+0x3af/0x750 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 12 Comm: kworker/u8:1 Not tainted 6.14.0-rc4-syzkaller-00278-gece144f151ac #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Workqueue: bat_events batadv_tt_purge RIP: 0010:bytes_is_nonzero mm/kasan/generic.c:87 [inline] RIP: 0010:memory_is_nonzero mm/kasan/generic.c:104 [inline] RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:129 [inline] RIP: 0010:memory_is_poisoned mm/kasan/generic.c:161 [inline] RIP: 0010:check_region_inline mm/kasan/generic.c:180 [inline] RIP: 0010:kasan_check_range+0x111/0x1a0 mm/kasan/generic.c:189 Code: 44 89 c2 e8 c1 ec ff ff 83 f0 01 5b 5d 41 5c c3 cc cc cc cc 48 85 d2 74 4f 48 01 ea eb 09 48 83 c0 01 48 39 d0 74 41 80 38 00 <74> f2 eb b2 41 bc 08 00 00 00 45 29 dc 49 8d 14 2c eb 0c 48 83 c0 RSP: 0018:ffffc90000006d00 EFLAGS: 00000046 RAX: fffffbfff2dd8598 RBX: fffffbfff2dd8599 RCX: ffffffff8195b7be RDX: fffffbfff2dd8599 RSI: 0000000000000008 RDI: ffffffff96ec2cc0 RBP: fffffbfff2dd8598 R08: 0000000000000000 R09: fffffbfff2dd8598 R10: ffffffff96ec2cc7 R11: 0000000000000005 R12: 0000000000000000 R13: ffff88801d28c880 R14: 0000000000000021 R15: ffff88801d28d438 FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffd2bf3df3c CR3: 0000000065902000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: instrument_atomic_read include/linux/instrumented.h:68 [inline] _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline] hlock_class+0x4e/0x130 kernel/locking/lockdep.c:230 check_wait_context kernel/locking/lockdep.c:4853 [inline] __lock_acquire+0x44d/0x3c40 kernel/locking/lockdep.c:5178 lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5851 rcu_lock_acquire include/linux/rcupdate.h:337 [inline] rcu_read_lock include/linux/rcupdate.h:849 [inline] ipv6_chk_mcast_addr+0x49/0x9a0 net/ipv6/mcast.c:1063 ip6_mc_input+0x392/0xfd0 net/ipv6/ip6_input.c:525 dst_input include/net/dst.h:469 [inline] dst_input include/net/dst.h:467 [inline] ip6_rcv_finish+0x3a2/0x5b0 net/ipv6/ip6_input.c:79 ip_sabotage_in+0x21b/0x290 net/bridge/br_netfilter_hooks.c:993 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_slow+0xbb/0x200 net/netfilter/core.c:626 nf_hook.constprop.0+0x42e/0x750 include/linux/netfilter.h:269 NF_HOOK include/linux/netfilter.h:312 [inline] ipv6_rcv+0xa4/0x680 net/ipv6/ip6_input.c:309 __netif_receive_skb_one_core+0x12e/0x1e0 net/core/dev.c:5893 __netif_receive_skb+0x1d/0x160 net/core/dev.c:6006 netif_receive_skb_internal net/core/dev.c:6092 [inline] netif_receive_skb+0x13f/0x7b0 net/core/dev.c:6151 NF_HOOK include/linux/netfilter.h:314 [inline] NF_HOOK include/linux/netfilter.h:308 [inline] br_pass_frame_up+0x346/0x490 net/bridge/br_input.c:70 br_handle_frame_finish+0xecc/0x1c90 net/bridge/br_input.c:226 br_nf_hook_thresh+0x303/0x410 net/bridge/br_netfilter_hooks.c:1170 br_nf_pre_routing_finish_ipv6+0x76a/0xfb0 net/bridge/br_netfilter_ipv6.c:154 NF_HOOK include/linux/netfilter.h:314 [inline] br_nf_pre_routing_ipv6+0x3ce/0x8c0 net/bridge/br_netfilter_ipv6.c:184 br_nf_pre_routing+0x860/0x15b0 net/bridge/br_netfilter_hooks.c:508 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_bridge_pre net/bridge/br_input.c:282 [inline] br_handle_frame+0xad7/0x14a0 net/bridge/br_input.c:433 __netif_receive_skb_core.constprop.0+0xa20/0x4330 net/core/dev.c:5787 __netif_receive_skb_one_core+0xb1/0x1e0 net/core/dev.c:5891 __netif_receive_skb+0x1d/0x160 net/core/dev.c:6006 process_backlog+0x443/0x15f0 net/core/dev.c:6354 __napi_poll.constprop.0+0xb7/0x550 net/core/dev.c:7188 napi_poll net/core/dev.c:7257 [inline] net_rx_action+0xa94/0x1010 net/core/dev.c:7379 handle_softirqs+0x213/0x8f0 kernel/softirq.c:561 do_softirq kernel/softirq.c:462 [inline] do_softirq+0xb2/0xf0 kernel/softirq.c:449 __local_bh_enable_ip+0x100/0x120 kernel/softirq.c:389 spin_unlock_bh include/linux/spinlock.h:396 [inline] batadv_tt_global_purge net/batman-adv/translation-table.c:2250 [inline] batadv_tt_purge+0x251/0xb90 net/batman-adv/translation-table.c:3510 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3400 kthread+0x3af/0x750 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244