===================================================== WARNING: SOFTIRQ-READ-safe -> SOFTIRQ-READ-unsafe lock order detected 6.11.0-syzkaller-12113-ge7ed34365879 #0 Not tainted ----------------------------------------------------- syz.1.1678/10489 [HC0[0]:SC0[8]:HE1:SE0] is trying to acquire: ffff888055afc9e0 (&pch->downl){+.+.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] ffff888055afc9e0 (&pch->downl){+.+.}-{2:2}, at: ppp_connect_channel drivers/net/ppp/ppp_generic.c:3485 [inline] ffff888055afc9e0 (&pch->downl){+.+.}-{2:2}, at: ppp_ioctl+0x1955/0x2590 drivers/net/ppp/ppp_generic.c:761 and this task is already holding: ffff88804d366e10 (&ppp->rlock){+...}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] ffff88804d366e10 (&ppp->rlock){+...}-{2:2}, at: ppp_connect_channel drivers/net/ppp/ppp_generic.c:3484 [inline] ffff88804d366e10 (&ppp->rlock){+...}-{2:2}, at: ppp_ioctl+0x1942/0x2590 drivers/net/ppp/ppp_generic.c:761 which would create a new lock dependency: (&ppp->rlock){+...}-{2:2} -> (&pch->downl){+.+.}-{2:2} but this new dependency connects a SOFTIRQ-READ-irq-safe lock: (&pch->upl){++.-}-{2:2} ... which became SOFTIRQ-READ-irq-safe at: lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5825 __raw_read_lock_bh include/linux/rwlock_api_smp.h:176 [inline] _raw_read_lock_bh+0x3f/0x70 kernel/locking/spinlock.c:252 ppp_input+0x40c/0xbb0 drivers/net/ppp/ppp_generic.c:2307 ppp_async_process+0x37/0x150 drivers/net/ppp/ppp_async.c:495 tasklet_action_common+0x24c/0x3e0 kernel/softirq.c:784 handle_softirqs+0x213/0x8f0 kernel/softirq.c:554 __do_softirq kernel/softirq.c:588 [inline] invoke_softirq kernel/softirq.c:428 [inline] __irq_exit_rcu kernel/softirq.c:637 [inline] irq_exit_rcu+0xbb/0x120 kernel/softirq.c:649 instr_sysvec_call_function_single arch/x86/kernel/smp.c:266 [inline] sysvec_call_function_single+0xa4/0xc0 arch/x86/kernel/smp.c:266 asm_sysvec_call_function_single+0x1a/0x20 arch/x86/include/asm/idtentry.h:709 __tasklet_schedule_common+0x10d/0x190 kernel/softirq.c:733 tasklet_schedule include/linux/interrupt.h:719 [inline] ppp_asynctty_receive+0x1147/0x15c0 drivers/net/ppp/ppp_async.c:345 tty_ldisc_receive_buf+0x153/0x190 drivers/tty/tty_buffer.c:391 tty_port_default_receive_buf+0x70/0xb0 drivers/tty/tty_port.c:37 receive_buf drivers/tty/tty_buffer.c:445 [inline] flush_to_ldisc+0x264/0x780 drivers/tty/tty_buffer.c:495 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3229 process_scheduled_works kernel/workqueue.c:3310 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 to a SOFTIRQ-READ-irq-unsafe lock: (&pch->downl){+.+.}-{2:2} ... which became SOFTIRQ-READ-irq-unsafe at: ... lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5825 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] ppp_channel_bridge_input drivers/net/ppp/ppp_generic.c:2272 [inline] ppp_input+0x104/0xbb0 drivers/net/ppp/ppp_generic.c:2304 pppoe_rcv_core+0x22c/0x320 drivers/net/ppp/pppoe.c:379 sk_backlog_rcv include/net/sock.h:1113 [inline] __release_sock+0x35f/0x400 net/core/sock.c:3072 release_sock+0x5a/0x220 net/core/sock.c:3626 pppoe_sendmsg+0x5e6/0x770 drivers/net/ppp/pppoe.c:903 sock_sendmsg_nosec net/socket.c:729 [inline] __sock_sendmsg net/socket.c:744 [inline] ____sys_sendmsg+0xaaf/0xc90 net/socket.c:2602 ___sys_sendmsg+0x135/0x1e0 net/socket.c:2656 __sys_sendmmsg+0x1a1/0x450 net/socket.c:2742 __do_sys_sendmmsg net/socket.c:2771 [inline] __se_sys_sendmmsg net/socket.c:2768 [inline] __x64_sys_sendmmsg+0x9c/0x100 net/socket.c:2768 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 other info that might help us debug this: Chain exists of: &pch->upl --> &ppp->rlock --> &pch->downl Possible interrupt unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&pch->downl); local_irq_disable(); lock(&pch->upl); lock(&ppp->rlock); lock(&pch->upl); *** DEADLOCK *** 5 locks held by syz.1.1678/10489: #0: ffffffff8f32ca28 (ppp_mutex){+.+.}-{3:3}, at: ppp_ioctl+0xc3/0x2590 drivers/net/ppp/ppp_generic.c:729 #1: ffff888028e224c0 (&pn->all_ppp_mutex){+.+.}-{3:3}, at: ppp_connect_channel drivers/net/ppp/ppp_generic.c:3474 [inline] #1: ffff888028e224c0 (&pn->all_ppp_mutex){+.+.}-{3:3}, at: ppp_ioctl+0xa5c/0x2590 drivers/net/ppp/ppp_generic.c:761 #2: ffff888055afca48 (&pch->upl){++.-}-{2:2}, at: ppp_connect_channel drivers/net/ppp/ppp_generic.c:3478 [inline] #2: ffff888055afca48 (&pch->upl){++.-}-{2:2}, at: ppp_ioctl+0xa8e/0x2590 drivers/net/ppp/ppp_generic.c:761 #3: ffff88804d366e50 (&ppp->wlock){+...}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] #3: ffff88804d366e50 (&ppp->wlock){+...}-{2:2}, at: ppp_connect_channel drivers/net/ppp/ppp_generic.c:3484 [inline] #3: ffff88804d366e50 (&ppp->wlock){+...}-{2:2}, at: ppp_ioctl+0x192d/0x2590 drivers/net/ppp/ppp_generic.c:761 #4: ffff88804d366e10 (&ppp->rlock){+...}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] #4: ffff88804d366e10 (&ppp->rlock){+...}-{2:2}, at: ppp_connect_channel drivers/net/ppp/ppp_generic.c:3484 [inline] #4: ffff88804d366e10 (&ppp->rlock){+...}-{2:2}, at: ppp_ioctl+0x1942/0x2590 drivers/net/ppp/ppp_generic.c:761 the dependencies between SOFTIRQ-READ-irq-safe lock and the holding lock: -> (&pch->upl){++.-}-{2:2} { HARDIRQ-ON-W at: lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5825 __raw_write_lock_bh include/linux/rwlock_api_smp.h:202 [inline] _raw_write_lock_bh+0x33/0x40 kernel/locking/spinlock.c:334 ppp_disconnect_channel+0x25/0x340 drivers/net/ppp/ppp_generic.c:3522 ppp_unregister_channel+0xb2/0x380 drivers/net/ppp/ppp_generic.c:2996 pppox_unbind_sock drivers/net/ppp/pppox.c:58 [inline] pppox_unbind_sock+0x66/0xb0 drivers/net/ppp/pppox.c:53 pppoe_release+0x163/0x470 drivers/net/ppp/pppoe.c:584 __sock_release+0xb0/0x270 net/socket.c:658 sock_close+0x1c/0x30 net/socket.c:1426 __fput+0x3f6/0xb60 fs/file_table.c:431 task_work_run+0x14e/0x250 kernel/task_work.c:228 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x27b/0x2a0 kernel/entry/common.c:218 do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f HARDIRQ-ON-R at: lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5825 __raw_read_lock_bh include/linux/rwlock_api_smp.h:176 [inline] _raw_read_lock_bh+0x3f/0x70 kernel/locking/spinlock.c:252 ppp_channel_push+0x28/0x250 drivers/net/ppp/ppp_generic.c:2186 ppp_write+0x2d1/0x3e0 drivers/net/ppp/ppp_generic.c:540 do_loop_readv_writev fs/read_write.c:857 [inline] do_loop_readv_writev fs/read_write.c:842 [inline] vfs_writev+0x6da/0xdd0 fs/read_write.c:1066 do_pwritev fs/read_write.c:1165 [inline] __do_sys_pwritev fs/read_write.c:1212 [inline] __se_sys_pwritev fs/read_write.c:1207 [inline] __x64_sys_pwritev+0x22d/0x310 fs/read_write.c:1207 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 IN-SOFTIRQ-R at: lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5825 __raw_read_lock_bh include/linux/rwlock_api_smp.h:176 [inline] _raw_read_lock_bh+0x3f/0x70 kernel/locking/spinlock.c:252 ppp_input+0x40c/0xbb0 drivers/net/ppp/ppp_generic.c:2307 ppp_async_process+0x37/0x150 drivers/net/ppp/ppp_async.c:495 tasklet_action_common+0x24c/0x3e0 kernel/softirq.c:784 handle_softirqs+0x213/0x8f0 kernel/softirq.c:554 __do_softirq kernel/softirq.c:588 [inline] invoke_softirq kernel/softirq.c:428 [inline] __irq_exit_rcu kernel/softirq.c:637 [inline] irq_exit_rcu+0xbb/0x120 kernel/softirq.c:649 instr_sysvec_call_function_single arch/x86/kernel/smp.c:266 [inline] sysvec_call_function_single+0xa4/0xc0 arch/x86/kernel/smp.c:266 asm_sysvec_call_function_single+0x1a/0x20 arch/x86/include/asm/idtentry.h:709 __tasklet_schedule_common+0x10d/0x190 kernel/softirq.c:733 tasklet_schedule include/linux/interrupt.h:719 [inline] ppp_asynctty_receive+0x1147/0x15c0 drivers/net/ppp/ppp_async.c:345 tty_ldisc_receive_buf+0x153/0x190 drivers/tty/tty_buffer.c:391 tty_port_default_receive_buf+0x70/0xb0 drivers/tty/tty_port.c:37 receive_buf drivers/tty/tty_buffer.c:445 [inline] flush_to_ldisc+0x264/0x780 drivers/tty/tty_buffer.c:495 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3229 process_scheduled_works kernel/workqueue.c:3310 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 INITIAL USE at: lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5825 __raw_write_lock_bh include/linux/rwlock_api_smp.h:202 [inline] _raw_write_lock_bh+0x33/0x40 kernel/locking/spinlock.c:334 ppp_disconnect_channel+0x25/0x340 drivers/net/ppp/ppp_generic.c:3522 ppp_unregister_channel+0xb2/0x380 drivers/net/ppp/ppp_generic.c:2996 pppox_unbind_sock drivers/net/ppp/pppox.c:58 [inline] pppox_unbind_sock+0x66/0xb0 drivers/net/ppp/pppox.c:53 pppoe_release+0x163/0x470 drivers/net/ppp/pppoe.c:584 __sock_release+0xb0/0x270 net/socket.c:658 sock_close+0x1c/0x30 net/socket.c:1426 __fput+0x3f6/0xb60 fs/file_table.c:431 task_work_run+0x14e/0x250 kernel/task_work.c:228 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x27b/0x2a0 kernel/entry/common.c:218 do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f INITIAL READ USE at: lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5825 __raw_read_lock_bh include/linux/rwlock_api_smp.h:176 [inline] _raw_read_lock_bh+0x3f/0x70 kernel/locking/spinlock.c:252 ppp_channel_push+0x28/0x250 drivers/net/ppp/ppp_generic.c:2186 ppp_write+0x2d1/0x3e0 drivers/net/ppp/ppp_generic.c:540 do_loop_readv_writev fs/read_write.c:857 [inline] do_loop_readv_writev fs/read_write.c:842 [inline] vfs_writev+0x6da/0xdd0 fs/read_write.c:1066 do_pwritev fs/read_write.c:1165 [inline] __do_sys_pwritev fs/read_write.c:1212 [inline] __se_sys_pwritev fs/read_write.c:1207 [inline] __x64_sys_pwritev+0x22d/0x310 fs/read_write.c:1207 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 } ... key at: [] __key.10+0x0/0x40 -> (&ppp->wlock){+...}-{2:2} { HARDIRQ-ON-W at: lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5825 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x33/0x40 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:356 [inline] ppp_get_stats64+0xcf/0x3a0 drivers/net/ppp/ppp_generic.c:1539 dev_get_stats+0xae/0xa00 net/core/dev.c:10937 rtnl_fill_stats+0x48/0xa90 net/core/rtnetlink.c:1268 rtnl_fill_ifinfo.constprop.0+0x1622/0x4b50 net/core/rtnetlink.c:1909 rtmsg_ifinfo_build_skb+0x151/0x280 net/core/rtnetlink.c:4079 rtmsg_ifinfo_event net/core/rtnetlink.c:4112 [inline] rtmsg_ifinfo_event net/core/rtnetlink.c:4102 [inline] rtmsg_ifinfo+0x9f/0x1a0 net/core/rtnetlink.c:4121 register_netdevice+0x18b5/0x1e90 net/core/dev.c:10534 ppp_unit_register drivers/net/ppp/ppp_generic.c:1219 [inline] ppp_dev_configure+0x99e/0xc80 drivers/net/ppp/ppp_generic.c:1275 ppp_create_interface drivers/net/ppp/ppp_generic.c:3348 [inline] ppp_unattached_ioctl drivers/net/ppp/ppp_generic.c:1060 [inline] ppp_ioctl+0x17eb/0x2590 drivers/net/ppp/ppp_generic.c:733 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl fs/ioctl.c:893 [inline] __x64_sys_ioctl+0x18f/0x220 fs/ioctl.c:893 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 INITIAL USE at: lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5825 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x33/0x40 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:356 [inline] ppp_get_stats64+0xcf/0x3a0 drivers/net/ppp/ppp_generic.c:1539 dev_get_stats+0xae/0xa00 net/core/dev.c:10937 rtnl_fill_stats+0x48/0xa90 net/core/rtnetlink.c:1268 rtnl_fill_ifinfo.constprop.0+0x1622/0x4b50 net/core/rtnetlink.c:1909 rtmsg_ifinfo_build_skb+0x151/0x280 net/core/rtnetlink.c:4079 rtmsg_ifinfo_event net/core/rtnetlink.c:4112 [inline] rtmsg_ifinfo_event net/core/rtnetlink.c:4102 [inline] rtmsg_ifinfo+0x9f/0x1a0 net/core/rtnetlink.c:4121 register_netdevice+0x18b5/0x1e90 net/core/dev.c:10534 ppp_unit_register drivers/net/ppp/ppp_generic.c:1219 [inline] ppp_dev_configure+0x99e/0xc80 drivers/net/ppp/ppp_generic.c:1275 ppp_create_interface drivers/net/ppp/ppp_generic.c:3348 [inline] ppp_unattached_ioctl drivers/net/ppp/ppp_generic.c:1060 [inline] ppp_ioctl+0x17eb/0x2590 drivers/net/ppp/ppp_generic.c:733 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl fs/ioctl.c:893 [inline] __x64_sys_ioctl+0x18f/0x220 fs/ioctl.c:893 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 } ... key at: [] __key.0+0x0/0x40 ... acquired at: __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x33/0x40 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:356 [inline] ppp_connect_channel drivers/net/ppp/ppp_generic.c:3484 [inline] ppp_ioctl+0x192d/0x2590 drivers/net/ppp/ppp_generic.c:761 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl fs/ioctl.c:893 [inline] __x64_sys_ioctl+0x18f/0x220 fs/ioctl.c:893 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 -> (&ppp->rlock){+...}-{2:2} { HARDIRQ-ON-W at: lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5825 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x33/0x40 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:356 [inline] ppp_get_stats64+0x24/0x3a0 drivers/net/ppp/ppp_generic.c:1534 dev_get_stats+0xae/0xa00 net/core/dev.c:10937 rtnl_fill_stats+0x48/0xa90 net/core/rtnetlink.c:1268 rtnl_fill_ifinfo.constprop.0+0x1622/0x4b50 net/core/rtnetlink.c:1909 rtmsg_ifinfo_build_skb+0x151/0x280 net/core/rtnetlink.c:4079 rtmsg_ifinfo_event net/core/rtnetlink.c:4112 [inline] rtmsg_ifinfo_event net/core/rtnetlink.c:4102 [inline] rtmsg_ifinfo+0x9f/0x1a0 net/core/rtnetlink.c:4121 register_netdevice+0x18b5/0x1e90 net/core/dev.c:10534 ppp_unit_register drivers/net/ppp/ppp_generic.c:1219 [inline] ppp_dev_configure+0x99e/0xc80 drivers/net/ppp/ppp_generic.c:1275 ppp_create_interface drivers/net/ppp/ppp_generic.c:3348 [inline] ppp_unattached_ioctl drivers/net/ppp/ppp_generic.c:1060 [inline] ppp_ioctl+0x17eb/0x2590 drivers/net/ppp/ppp_generic.c:733 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl fs/ioctl.c:893 [inline] __x64_sys_ioctl+0x18f/0x220 fs/ioctl.c:893 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 INITIAL USE at: lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5825 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x33/0x40 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:356 [inline] ppp_get_stats64+0x24/0x3a0 drivers/net/ppp/ppp_generic.c:1534 dev_get_stats+0xae/0xa00 net/core/dev.c:10937 rtnl_fill_stats+0x48/0xa90 net/core/rtnetlink.c:1268 rtnl_fill_ifinfo.constprop.0+0x1622/0x4b50 net/core/rtnetlink.c:1909 rtmsg_ifinfo_build_skb+0x151/0x280 net/core/rtnetlink.c:4079 rtmsg_ifinfo_event net/core/rtnetlink.c:4112 [inline] rtmsg_ifinfo_event net/core/rtnetlink.c:4102 [inline] rtmsg_ifinfo+0x9f/0x1a0 net/core/rtnetlink.c:4121 register_netdevice+0x18b5/0x1e90 net/core/dev.c:10534 ppp_unit_register drivers/net/ppp/ppp_generic.c:1219 [inline] ppp_dev_configure+0x99e/0xc80 drivers/net/ppp/ppp_generic.c:1275 ppp_create_interface drivers/net/ppp/ppp_generic.c:3348 [inline] ppp_unattached_ioctl drivers/net/ppp/ppp_generic.c:1060 [inline] ppp_ioctl+0x17eb/0x2590 drivers/net/ppp/ppp_generic.c:733 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl fs/ioctl.c:893 [inline] __x64_sys_ioctl+0x18f/0x220 fs/ioctl.c:893 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 } ... key at: [] __key.1+0x0/0x40 ... acquired at: __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x33/0x40 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:356 [inline] ppp_ioctl+0x274/0x2590 drivers/net/ppp/ppp_generic.c:823 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl fs/ioctl.c:893 [inline] __x64_sys_ioctl+0x18f/0x220 fs/ioctl.c:893 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 the dependencies between the lock to be acquired and SOFTIRQ-READ-irq-unsafe lock: -> (&pch->downl){+.+.}-{2:2} { HARDIRQ-ON-W at: lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5825 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x33/0x40 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:356 [inline] ppp_unregister_channel+0x6d/0x380 drivers/net/ppp/ppp_generic.c:2992 pppox_unbind_sock drivers/net/ppp/pppox.c:58 [inline] pppox_unbind_sock+0x66/0xb0 drivers/net/ppp/pppox.c:53 pppoe_release+0x163/0x470 drivers/net/ppp/pppoe.c:584 __sock_release+0xb0/0x270 net/socket.c:658 sock_close+0x1c/0x30 net/socket.c:1426 __fput+0x3f6/0xb60 fs/file_table.c:431 task_work_run+0x14e/0x250 kernel/task_work.c:228 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x27b/0x2a0 kernel/entry/common.c:218 do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f SOFTIRQ-ON-W at: lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5825 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] ppp_channel_bridge_input drivers/net/ppp/ppp_generic.c:2272 [inline] ppp_input+0x104/0xbb0 drivers/net/ppp/ppp_generic.c:2304 pppoe_rcv_core+0x22c/0x320 drivers/net/ppp/pppoe.c:379 sk_backlog_rcv include/net/sock.h:1113 [inline] __release_sock+0x35f/0x400 net/core/sock.c:3072 release_sock+0x5a/0x220 net/core/sock.c:3626 pppoe_sendmsg+0x5e6/0x770 drivers/net/ppp/pppoe.c:903 sock_sendmsg_nosec net/socket.c:729 [inline] __sock_sendmsg net/socket.c:744 [inline] ____sys_sendmsg+0xaaf/0xc90 net/socket.c:2602 ___sys_sendmsg+0x135/0x1e0 net/socket.c:2656 __sys_sendmmsg+0x1a1/0x450 net/socket.c:2742 __do_sys_sendmmsg net/socket.c:2771 [inline] __se_sys_sendmmsg net/socket.c:2768 [inline] __x64_sys_sendmmsg+0x9c/0x100 net/socket.c:2768 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 INITIAL USE at: lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5825 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x33/0x40 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:356 [inline] ppp_unregister_channel+0x6d/0x380 drivers/net/ppp/ppp_generic.c:2992 pppox_unbind_sock drivers/net/ppp/pppox.c:58 [inline] pppox_unbind_sock+0x66/0xb0 drivers/net/ppp/pppox.c:53 pppoe_release+0x163/0x470 drivers/net/ppp/pppoe.c:584 __sock_release+0xb0/0x270 net/socket.c:658 sock_close+0x1c/0x30 net/socket.c:1426 __fput+0x3f6/0xb60 fs/file_table.c:431 task_work_run+0x14e/0x250 kernel/task_work.c:228 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x27b/0x2a0 kernel/entry/common.c:218 do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f } ... key at: [] __key.11+0x0/0x40 ... acquired at: lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5825 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x33/0x40 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:356 [inline] ppp_connect_channel drivers/net/ppp/ppp_generic.c:3485 [inline] ppp_ioctl+0x1955/0x2590 drivers/net/ppp/ppp_generic.c:761 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl fs/ioctl.c:893 [inline] __x64_sys_ioctl+0x18f/0x220 fs/ioctl.c:893 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 stack backtrace: CPU: 0 UID: 0 PID: 10489 Comm: syz.1.1678 Not tainted 6.11.0-syzkaller-12113-ge7ed34365879 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_bad_irq_dependency kernel/locking/lockdep.c:2647 [inline] check_irq_usage+0xf22/0x1290 kernel/locking/lockdep.c:2888 check_prev_add kernel/locking/lockdep.c:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3280 [inline] validate_chain kernel/locking/lockdep.c:3904 [inline] __lock_acquire+0x2521/0x3ce0 kernel/locking/lockdep.c:5202 lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5825 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x33/0x40 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:356 [inline] ppp_connect_channel drivers/net/ppp/ppp_generic.c:3485 [inline] ppp_ioctl+0x1955/0x2590 drivers/net/ppp/ppp_generic.c:761 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl fs/ioctl.c:893 [inline] __x64_sys_ioctl+0x18f/0x220 fs/ioctl.c:893 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: 0033:0x7fbbb0d7dff9 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:00007fbbb1c58038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fbbb0f35f80 RCX: 00007fbbb0d7dff9 RDX: 0000000020000300 RSI: 000000004004743a RDI: 0000000000000006 RBP: 00007fbbb0df0296 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fbbb0f35f80 R15: 00007fffaf93ff68