WARNING: possible irq lock inversion dependency detected 6.5.0-rc6-syzkaller-00038-g16931859a650 #0 Not tainted -------------------------------------------------------- kworker/u4:19/7759 just changed the state of lock: ffffffff8d9475f8 (disc_data_lock#2){.?..}-{2:2}, at: ap_get+0x18/0xf0 drivers/net/ppp/ppp_async.c:136 but this lock was taken by another, HARDIRQ-safe lock in the past: (&port_lock_key){-.-.}-{2:2} and interrupts could create inverse lock ordering between them. other info that might help us debug this: Possible interrupt unsafe locking scenario: CPU0 CPU1 ---- ---- lock(disc_data_lock#2); local_irq_disable(); lock(&port_lock_key); lock(disc_data_lock#2); lock(&port_lock_key); *** DEADLOCK *** 4 locks held by kworker/u4:19/7759: #0: ffff888012879138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:20 [inline] #0: ffff888012879138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: raw_atomic64_set include/linux/atomic/atomic-arch-fallback.h:2608 [inline] #0: ffff888012879138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: raw_atomic_long_set include/linux/atomic/atomic-long.h:79 [inline] #0: ffff888012879138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:3196 [inline] #0: ffff888012879138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:678 [inline] #0: ffff888012879138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:705 [inline] #0: ffff888012879138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x96a/0x16f0 kernel/workqueue.c:2570 #1: ffffc90009907d80 ((work_completion)(&buf->work)){+.+.}-{0:0}, at: process_one_work+0x99e/0x16f0 kernel/workqueue.c:2574 #2: ffff88805d2e88b8 (&buf->lock){+.+.}-{3:3}, at: flush_to_ldisc+0x30/0x7c0 drivers/tty/tty_buffer.c:537 #3: ffff88804aa9e098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref+0x1c/0x80 drivers/tty/tty_ldisc.c:263 the shortest dependencies between 2nd lock and 1st lock: -> (&port_lock_key){-.-.}-{2:2} { IN-HARDIRQ-W at: lock_acquire kernel/locking/lockdep.c:5761 [inline] lock_acquire+0x1ae/0x510 kernel/locking/lockdep.c:5726 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x50 kernel/locking/spinlock.c:162 serial8250_handle_irq+0x91/0xbe0 drivers/tty/serial/8250/8250_port.c:1917 serial8250_default_handle_irq+0x94/0x210 drivers/tty/serial/8250/8250_port.c:1963 serial8250_interrupt+0xfc/0x200 drivers/tty/serial/8250/8250_core.c:127 __handle_irq_event_percpu+0x22a/0x740 kernel/irq/handle.c:158 handle_irq_event_percpu kernel/irq/handle.c:193 [inline] handle_irq_event+0xab/0x1e0 kernel/irq/handle.c:210 handle_edge_irq+0x261/0xcf0 kernel/irq/chip.c:834 generic_handle_irq_desc include/linux/irqdesc.h:161 [inline] handle_irq arch/x86/kernel/irq.c:238 [inline] __common_interrupt+0x9f/0x220 arch/x86/kernel/irq.c:257 common_interrupt+0xa9/0xd0 arch/x86/kernel/irq.c:247 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:636 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:151 [inline] _raw_spin_unlock_irqrestore+0x31/0x70 kernel/locking/spinlock.c:194 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline] serial_port_runtime_resume+0x2ae/0x330 drivers/tty/serial/serial_port.c:41 __rpm_callback+0xc5/0x4c0 drivers/base/power/runtime.c:392 rpm_callback+0x1da/0x220 drivers/base/power/runtime.c:446 rpm_resume+0xdb9/0x1980 drivers/base/power/runtime.c:912 pm_runtime_work+0x12e/0x180 drivers/base/power/runtime.c:977 process_one_work+0xaa2/0x16f0 kernel/workqueue.c:2600 worker_thread+0x687/0x1110 kernel/workqueue.c:2751 kthread+0x33a/0x430 kernel/kthread.c:389 ret_from_fork+0x2c/0x70 arch/x86/kernel/process.c:145 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 IN-SOFTIRQ-W at: lock_acquire kernel/locking/lockdep.c:5761 [inline] lock_acquire+0x1ae/0x510 kernel/locking/lockdep.c:5726 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x50 kernel/locking/spinlock.c:162 serial8250_console_write+0x57e/0x1060 drivers/tty/serial/8250/8250_port.c:3403 console_emit_next_record kernel/printk/printk.c:2877 [inline] console_flush_all+0x4c8/0xf50 kernel/printk/printk.c:2933 console_unlock+0xc6/0x1f0 kernel/printk/printk.c:3007 vprintk_emit+0x1c5/0x640 kernel/printk/printk.c:2307 vprintk+0x89/0xa0 kernel/printk/printk_safe.c:50 _printk+0xc8/0x100 kernel/printk/printk.c:2328 tcp_syn_flood_action+0x3fb/0x460 net/ipv4/tcp_input.c:6856 tcp_conn_request+0x171c/0x3460 net/ipv4/tcp_input.c:6953 tcp_v6_conn_request+0x1eb/0x460 net/ipv6/tcp_ipv6.c:1176 tcp_rcv_state_process+0x11ba/0x4d20 net/ipv4/tcp_input.c:6494 tcp_v6_do_rcv+0x408/0x15f0 net/ipv6/tcp_ipv6.c:1510 tcp_v6_rcv+0x2c53/0x3160 net/ipv6/tcp_ipv6.c:1736 ip6_protocol_deliver_rcu+0x33b/0x13d0 net/ipv6/ip6_input.c:437 ip6_input_finish+0x151/0x300 net/ipv6/ip6_input.c:482 NF_HOOK include/linux/netfilter.h:303 [inline] NF_HOOK include/linux/netfilter.h:297 [inline] ip6_input+0xca/0x420 net/ipv6/ip6_input.c:491 dst_input include/net/dst.h:468 [inline] ip6_rcv_finish net/ipv6/ip6_input.c:79 [inline] NF_HOOK include/linux/netfilter.h:303 [inline] NF_HOOK include/linux/netfilter.h:297 [inline] ipv6_rcv+0x4a9/0x6f0 net/ipv6/ip6_input.c:309 __netif_receive_skb_one_core+0x115/0x180 net/core/dev.c:5452 __netif_receive_skb+0x1f/0x1b0 net/core/dev.c:5566 process_backlog+0x101/0x6c0 net/core/dev.c:5894 __napi_poll.constprop.0+0xb4/0x530 net/core/dev.c:6460 napi_poll net/core/dev.c:6527 [inline] net_rx_action+0x956/0xe90 net/core/dev.c:6660 __do_softirq+0x218/0x965 kernel/softirq.c:553 do_softirq kernel/softirq.c:454 [inline] do_softirq+0xaa/0xe0 kernel/softirq.c:441 __local_bh_enable_ip+0xf8/0x120 kernel/softirq.c:381 local_bh_enable include/linux/bottom_half.h:33 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:819 [inline] __dev_queue_xmit+0xb1d/0x3f20 net/core/dev.c:4230 dev_queue_xmit include/linux/netdevice.h:3088 [inline] neigh_hh_output include/net/neighbour.h:528 [inline] neigh_output include/net/neighbour.h:542 [inline] ip6_finish_output2+0x1083/0x1b20 net/ipv6/ip6_output.c:135 __ip6_finish_output net/ipv6/ip6_output.c:196 [inline] ip6_finish_output+0x485/0x11d0 net/ipv6/ip6_output.c:207 NF_HOOK_COND include/linux/netfilter.h:292 [inline] ip6_output+0x243/0x890 net/ipv6/ip6_output.c:228 dst_output include/net/dst.h:458 [inline] NF_HOOK include/linux/netfilter.h:303 [inline] NF_HOOK include/linux/netfilter.h:297 [inline] ip6_xmit+0xe1d/0x1fe0 net/ipv6/ip6_output.c:344 inet6_csk_xmit+0x3c0/0x730 net/ipv6/inet6_connection_sock.c:135 __tcp_transmit_skb+0x199b/0x3a80 net/ipv4/tcp_output.c:1401 tcp_transmit_skb net/ipv4/tcp_output.c:1419 [inline] tcp_send_syn_data net/ipv4/tcp_output.c:3914 [inline] tcp_connect+0x24e3/0x5730 net/ipv4/tcp_output.c:3953 tcp_v6_connect+0x1476/0x1fb0 net/ipv6/tcp_ipv6.c:338 __inet_stream_connect+0x947/0xe10 net/ipv4/af_inet.c:666 tcp_sendmsg_fastopen+0x3ce/0x710 net/ipv4/tcp.c:1019 tcp_sendmsg_locked+0x1e5f/0x3420 net/ipv4/tcp.c:1070 tcp_sendmsg+0x2e/0x40 net/ipv4/tcp.c:1333 inet6_sendmsg+0x9d/0xe0 net/ipv6/af_inet6.c:651 sock_sendmsg_nosec net/socket.c:725 [inline] sock_sendmsg+0xd9/0x180 net/socket.c:748 __sys_sendto+0x255/0x340 net/socket.c:2134 __do_sys_sendto net/socket.c:2146 [inline] __se_sys_sendto net/socket.c:2142 [inline] __ia32_sys_sendto+0xdd/0x1b0 net/socket.c:2142 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline] __do_fast_syscall_32+0x61/0xe0 arch/x86/entry/common.c:178 do_fast_syscall_32+0x33/0x70 arch/x86/entry/common.c:203 entry_SYSENTER_compat_after_hwframe+0x70/0x82 INITIAL USE at: lock_acquire kernel/locking/lockdep.c:5761 [inline] lock_acquire+0x1ae/0x510 kernel/locking/lockdep.c:5726 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x50 kernel/locking/spinlock.c:162 serial8250_do_set_termios+0x334/0x1240 drivers/tty/serial/8250/8250_port.c:2794 serial8250_set_termios+0x6b/0x80 drivers/tty/serial/8250/8250_port.c:2913 uart_set_options+0x30e/0x5e0 drivers/tty/serial/serial_core.c:2284 serial8250_console_setup+0x18a/0x430 drivers/tty/serial/8250/8250_port.c:3507 univ8250_console_setup+0x168/0x210 drivers/tty/serial/8250/8250_core.c:631 try_enable_preferred_console+0x24d/0x470 kernel/printk/printk.c:3228 register_console+0x331/0x10d0 kernel/printk/printk.c:3401 univ8250_console_init+0x35/0x50 drivers/tty/serial/8250/8250_core.c:716 console_init+0xba/0x5c0 kernel/printk/printk.c:3601 start_kernel+0x25a/0x480 init/main.c:1004 x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:556 x86_64_start_kernel+0xb2/0xc0 arch/x86/kernel/head64.c:537 secondary_startup_64_no_verify+0x167/0x16b } ... key at: [] port_lock_key+0x0/0x40 ... acquired at: __raw_read_lock include/linux/rwlock_api_smp.h:150 [inline] _raw_read_lock+0x3a/0x70 kernel/locking/spinlock.c:228 ap_get+0x18/0xf0 drivers/net/ppp/ppp_async.c:136 ppp_asynctty_wakeup+0x18/0xb0 drivers/net/ppp/ppp_async.c:360 tty_wakeup+0xe5/0x120 drivers/tty/tty_io.c:525 tty_port_default_wakeup+0x2a/0x40 drivers/tty/tty_port.c:71 serial8250_tx_chars+0x542/0xf60 drivers/tty/serial/8250/8250_port.c:1839 serial8250_handle_irq+0x5fb/0xbe0 drivers/tty/serial/8250/8250_port.c:1943 serial8250_default_handle_irq+0x94/0x210 drivers/tty/serial/8250/8250_port.c:1963 serial8250_interrupt+0xfc/0x200 drivers/tty/serial/8250/8250_core.c:127 __handle_irq_event_percpu+0x22a/0x740 kernel/irq/handle.c:158 handle_irq_event_percpu kernel/irq/handle.c:193 [inline] handle_irq_event+0xab/0x1e0 kernel/irq/handle.c:210 handle_edge_irq+0x261/0xcf0 kernel/irq/chip.c:834 generic_handle_irq_desc include/linux/irqdesc.h:161 [inline] handle_irq arch/x86/kernel/irq.c:238 [inline] __common_interrupt+0x9f/0x220 arch/x86/kernel/irq.c:257 common_interrupt+0xa9/0xd0 arch/x86/kernel/irq.c:247 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:636 in_irqentry_text kernel/stacktrace.c:379 [inline] filter_irq_stacks+0x56/0x90 kernel/stacktrace.c:395 __stack_depot_save+0x39/0x510 lib/stackdepot.c:377 kasan_save_stack+0x43/0x50 mm/kasan/common.c:46 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 kasan_save_free_info+0x2b/0x40 mm/kasan/generic.c:522 ____kasan_slab_free mm/kasan/common.c:236 [inline] ____kasan_slab_free+0x15e/0x1b0 mm/kasan/common.c:200 kasan_slab_free include/linux/kasan.h:162 [inline] slab_free_hook mm/slub.c:1792 [inline] slab_free_freelist_hook+0x10b/0x1e0 mm/slub.c:1818 slab_free mm/slub.c:3801 [inline] __kmem_cache_free+0xb8/0x2f0 mm/slub.c:3814 batadv_mcast_mla_list_free net/batman-adv/multicast.c:638 [inline] __batadv_mcast_mla_update net/batman-adv/multicast.c:893 [inline] batadv_mcast_mla_update+0x17ed/0x2d90 net/batman-adv/multicast.c:915 process_one_work+0xaa2/0x16f0 kernel/workqueue.c:2600 worker_thread+0x687/0x1110 kernel/workqueue.c:2751 kthread+0x33a/0x430 kernel/kthread.c:389 ret_from_fork+0x2c/0x70 arch/x86/kernel/process.c:145 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 -> (disc_data_lock#2){.?..}-{2:2} { IN-HARDIRQ-R at: lock_acquire kernel/locking/lockdep.c:5761 [inline] lock_acquire+0x1ae/0x510 kernel/locking/lockdep.c:5726 __raw_read_lock include/linux/rwlock_api_smp.h:150 [inline] _raw_read_lock+0x3a/0x70 kernel/locking/spinlock.c:228 ap_get+0x18/0xf0 drivers/net/ppp/ppp_async.c:136 ppp_asynctty_wakeup+0x18/0xb0 drivers/net/ppp/ppp_async.c:360 tty_wakeup+0xe5/0x120 drivers/tty/tty_io.c:525 tty_port_default_wakeup+0x2a/0x40 drivers/tty/tty_port.c:71 serial8250_tx_chars+0x542/0xf60 drivers/tty/serial/8250/8250_port.c:1839 serial8250_handle_irq+0x5fb/0xbe0 drivers/tty/serial/8250/8250_port.c:1943 serial8250_default_handle_irq+0x94/0x210 drivers/tty/serial/8250/8250_port.c:1963 serial8250_interrupt+0xfc/0x200 drivers/tty/serial/8250/8250_core.c:127 __handle_irq_event_percpu+0x22a/0x740 kernel/irq/handle.c:158 handle_irq_event_percpu kernel/irq/handle.c:193 [inline] handle_irq_event+0xab/0x1e0 kernel/irq/handle.c:210 handle_edge_irq+0x261/0xcf0 kernel/irq/chip.c:834 generic_handle_irq_desc include/linux/irqdesc.h:161 [inline] handle_irq arch/x86/kernel/irq.c:238 [inline] __common_interrupt+0x9f/0x220 arch/x86/kernel/irq.c:257 common_interrupt+0xa9/0xd0 arch/x86/kernel/irq.c:247 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:636 in_irqentry_text kernel/stacktrace.c:379 [inline] filter_irq_stacks+0x56/0x90 kernel/stacktrace.c:395 __stack_depot_save+0x39/0x510 lib/stackdepot.c:377 kasan_save_stack+0x43/0x50 mm/kasan/common.c:46 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 kasan_save_free_info+0x2b/0x40 mm/kasan/generic.c:522 ____kasan_slab_free mm/kasan/common.c:236 [inline] ____kasan_slab_free+0x15e/0x1b0 mm/kasan/common.c:200 kasan_slab_free include/linux/kasan.h:162 [inline] slab_free_hook mm/slub.c:1792 [inline] slab_free_freelist_hook+0x10b/0x1e0 mm/slub.c:1818 slab_free mm/slub.c:3801 [inline] __kmem_cache_free+0xb8/0x2f0 mm/slub.c:3814 batadv_mcast_mla_list_free net/batman-adv/multicast.c:638 [inline] __batadv_mcast_mla_update net/batman-adv/multicast.c:893 [inline] batadv_mcast_mla_update+0x17ed/0x2d90 net/batman-adv/multicast.c:915 process_one_work+0xaa2/0x16f0 kernel/workqueue.c:2600 worker_thread+0x687/0x1110 kernel/workqueue.c:2751 kthread+0x33a/0x430 kernel/kthread.c:389 ret_from_fork+0x2c/0x70 arch/x86/kernel/process.c:145 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 HARDIRQ-ON-R at: lock_acquire kernel/locking/lockdep.c:5761 [inline] lock_acquire+0x1ae/0x510 kernel/locking/lockdep.c:5726 __raw_read_lock include/linux/rwlock_api_smp.h:150 [inline] _raw_read_lock+0x5f/0x70 kernel/locking/spinlock.c:228 ap_get+0x18/0xf0 drivers/net/ppp/ppp_async.c:136 ppp_asynctty_receive+0x2f/0x1580 drivers/net/ppp/ppp_async.c:343 tty_ldisc_receive_buf+0x143/0x180 drivers/tty/tty_buffer.c:461 tty_port_default_receive_buf+0x6f/0xa0 drivers/tty/tty_port.c:39 receive_buf drivers/tty/tty_buffer.c:515 [inline] flush_to_ldisc+0x252/0x7c0 drivers/tty/tty_buffer.c:565 process_one_work+0xaa2/0x16f0 kernel/workqueue.c:2600 worker_thread+0x687/0x1110 kernel/workqueue.c:2751 kthread+0x33a/0x430 kernel/kthread.c:389 ret_from_fork+0x2c/0x70 arch/x86/kernel/process.c:145 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 INITIAL USE at: lock_acquire kernel/locking/lockdep.c:5761 [inline] lock_acquire+0x1ae/0x510 kernel/locking/lockdep.c:5726 __raw_write_lock_irq include/linux/rwlock_api_smp.h:195 [inline] _raw_write_lock_irq+0x36/0x50 kernel/locking/spinlock.c:326 ppp_asynctty_close+0x1c/0x1c0 drivers/net/ppp/ppp_async.c:219 tty_ldisc_close+0x111/0x190 drivers/tty/tty_ldisc.c:455 tty_ldisc_kill+0x94/0x150 drivers/tty/tty_ldisc.c:607 tty_ldisc_release+0x17b/0x2a0 drivers/tty/tty_ldisc.c:775 tty_release_struct+0x23/0xe0 drivers/tty/tty_io.c:1698 tty_release+0xe23/0x1410 drivers/tty/tty_io.c:1869 __fput+0x3f7/0xac0 fs/file_table.c:384 task_work_run+0x14d/0x240 kernel/task_work.c:179 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop kernel/entry/common.c:171 [inline] exit_to_user_mode_prepare+0x210/0x240 kernel/entry/common.c:204 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline] syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:297 __do_fast_syscall_32+0x6d/0xe0 arch/x86/entry/common.c:181 do_fast_syscall_32+0x33/0x70 arch/x86/entry/common.c:203 entry_SYSENTER_compat_after_hwframe+0x70/0x82 INITIAL READ USE at: lock_acquire kernel/locking/lockdep.c:5761 [inline] lock_acquire+0x1ae/0x510 kernel/locking/lockdep.c:5726 __raw_read_lock include/linux/rwlock_api_smp.h:150 [inline] _raw_read_lock+0x3a/0x70 kernel/locking/spinlock.c:228 ap_get+0x18/0xf0 drivers/net/ppp/ppp_async.c:136 ppp_asynctty_wakeup+0x18/0xb0 drivers/net/ppp/ppp_async.c:360 tty_wakeup+0xe5/0x120 drivers/tty/tty_io.c:525 tty_port_default_wakeup+0x2a/0x40 drivers/tty/tty_port.c:71 serial8250_tx_chars+0x542/0xf60 drivers/tty/serial/8250/8250_port.c:1839 serial8250_handle_irq+0x5fb/0xbe0 drivers/tty/serial/8250/8250_port.c:1943 serial8250_default_handle_irq+0x94/0x210 drivers/tty/serial/8250/8250_port.c:1963 serial8250_interrupt+0xfc/0x200 drivers/tty/serial/8250/8250_core.c:127 __handle_irq_event_percpu+0x22a/0x740 kernel/irq/handle.c:158 handle_irq_event_percpu kernel/irq/handle.c:193 [inline] handle_irq_event+0xab/0x1e0 kernel/irq/handle.c:210 handle_edge_irq+0x261/0xcf0 kernel/irq/chip.c:834 generic_handle_irq_desc include/linux/irqdesc.h:161 [inline] handle_irq arch/x86/kernel/irq.c:238 [inline] __common_interrupt+0x9f/0x220 arch/x86/kernel/irq.c:257 common_interrupt+0xa9/0xd0 arch/x86/kernel/irq.c:247 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:636 in_irqentry_text kernel/stacktrace.c:379 [inline] filter_irq_stacks+0x56/0x90 kernel/stacktrace.c:395 __stack_depot_save+0x39/0x510 lib/stackdepot.c:377 kasan_save_stack+0x43/0x50 mm/kasan/common.c:46 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 kasan_save_free_info+0x2b/0x40 mm/kasan/generic.c:522 ____kasan_slab_free mm/kasan/common.c:236 [inline] ____kasan_slab_free+0x15e/0x1b0 mm/kasan/common.c:200 kasan_slab_free include/linux/kasan.h:162 [inline] slab_free_hook mm/slub.c:1792 [inline] slab_free_freelist_hook+0x10b/0x1e0 mm/slub.c:1818 slab_free mm/slub.c:3801 [inline] __kmem_cache_free+0xb8/0x2f0 mm/slub.c:3814 batadv_mcast_mla_list_free net/batman-adv/multicast.c:638 [inline] __batadv_mcast_mla_update net/batman-adv/multicast.c:893 [inline] batadv_mcast_mla_update+0x17ed/0x2d90 net/batman-adv/multicast.c:915 process_one_work+0xaa2/0x16f0 kernel/workqueue.c:2600 worker_thread+0x687/0x1110 kernel/workqueue.c:2751 kthread+0x33a/0x430 kernel/kthread.c:389 ret_from_fork+0x2c/0x70 arch/x86/kernel/process.c:145 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 } ... key at: [] disc_data_lock+0x18/0x60 ... acquired at: mark_usage kernel/locking/lockdep.c:4586 [inline] __lock_acquire+0x13a5/0x5de0 kernel/locking/lockdep.c:5098 lock_acquire kernel/locking/lockdep.c:5761 [inline] lock_acquire+0x1ae/0x510 kernel/locking/lockdep.c:5726 __raw_read_lock include/linux/rwlock_api_smp.h:150 [inline] _raw_read_lock+0x5f/0x70 kernel/locking/spinlock.c:228 ap_get+0x18/0xf0 drivers/net/ppp/ppp_async.c:136 ppp_asynctty_receive+0x2f/0x1580 drivers/net/ppp/ppp_async.c:343 tty_ldisc_receive_buf+0x143/0x180 drivers/tty/tty_buffer.c:461 tty_port_default_receive_buf+0x6f/0xa0 drivers/tty/tty_port.c:39 receive_buf drivers/tty/tty_buffer.c:515 [inline] flush_to_ldisc+0x252/0x7c0 drivers/tty/tty_buffer.c:565 process_one_work+0xaa2/0x16f0 kernel/workqueue.c:2600 worker_thread+0x687/0x1110 kernel/workqueue.c:2751 kthread+0x33a/0x430 kernel/kthread.c:389 ret_from_fork+0x2c/0x70 arch/x86/kernel/process.c:145 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 stack backtrace: CPU: 1 PID: 7759 Comm: kworker/u4:19 Not tainted 6.5.0-rc6-syzkaller-00038-g16931859a650 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023 Workqueue: events_unbound flush_to_ldisc Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106 print_irq_inversion_bug.part.0+0x3e1/0x590 kernel/locking/lockdep.c:4087 print_irq_inversion_bug kernel/locking/lockdep.c:4040 [inline] check_usage_forwards kernel/locking/lockdep.c:4118 [inline] mark_lock_irq kernel/locking/lockdep.c:4250 [inline] mark_lock+0x920/0x1950 kernel/locking/lockdep.c:4685 mark_usage kernel/locking/lockdep.c:4586 [inline] __lock_acquire+0x13a5/0x5de0 kernel/locking/lockdep.c:5098 lock_acquire kernel/locking/lockdep.c:5761 [inline] lock_acquire+0x1ae/0x510 kernel/locking/lockdep.c:5726 __raw_read_lock include/linux/rwlock_api_smp.h:150 [inline] _raw_read_lock+0x5f/0x70 kernel/locking/spinlock.c:228 ap_get+0x18/0xf0 drivers/net/ppp/ppp_async.c:136 ppp_asynctty_receive+0x2f/0x1580 drivers/net/ppp/ppp_async.c:343 tty_ldisc_receive_buf+0x143/0x180 drivers/tty/tty_buffer.c:461 tty_port_default_receive_buf+0x6f/0xa0 drivers/tty/tty_port.c:39 receive_buf drivers/tty/tty_buffer.c:515 [inline] flush_to_ldisc+0x252/0x7c0 drivers/tty/tty_buffer.c:565 process_one_work+0xaa2/0x16f0 kernel/workqueue.c:2600 worker_thread+0x687/0x1110 kernel/workqueue.c:2751 kthread+0x33a/0x430 kernel/kthread.c:389 ret_from_fork+0x2c/0x70 arch/x86/kernel/process.c:145 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304