======================================================== WARNING: possible irq lock inversion dependency detected 6.12.0-rc1-syzkaller-00046-g7ec462100ef9 #0 Not tainted -------------------------------------------------------- syz.1.709/8854 just changed the state of lock: ffff88807b25c9e0 (&pch->downl){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] ffff88807b25c9e0 (&pch->downl){+.+.}-{2:2}, at: ppp_channel_bridge_input drivers/net/ppp/ppp_generic.c:2272 [inline] ffff88807b25c9e0 (&pch->downl){+.+.}-{2:2}, at: ppp_input+0x18b/0xa10 drivers/net/ppp/ppp_generic.c:2304 but this lock was taken by another, SOFTIRQ-safe lock in the past: (&ppp->rlock){+.-.}-{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(&pch->downl); local_irq_disable(); lock(&ppp->rlock); lock(&pch->downl); lock(&ppp->rlock); *** DEADLOCK *** 2 locks held by syz.1.709/8854: #0: ffff88802f7c9258 (sk_lock-AF_PPPOX){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1609 [inline] #0: ffff88802f7c9258 (sk_lock-AF_PPPOX){+.+.}-{0:0}, at: pppoe_sendmsg+0x51/0x750 drivers/net/ppp/pppoe.c:849 #1: ffffffff8e937de0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #1: ffffffff8e937de0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffffff8e937de0 (rcu_read_lock){....}-{1:2}, at: ppp_channel_bridge_input drivers/net/ppp/ppp_generic.c:2267 [inline] #1: ffffffff8e937de0 (rcu_read_lock){....}-{1:2}, at: ppp_input+0x55/0xa10 drivers/net/ppp/ppp_generic.c:2304 the shortest dependencies between 2nd lock and 1st lock: -> (&ppp->rlock){+.-.}-{2:2} { HARDIRQ-ON-W at: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x35/0x50 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:356 [inline] ppp_get_stats64+0x33/0x290 drivers/net/ppp/ppp_generic.c:1534 dev_get_stats+0xad/0xa00 net/core/dev.c:10937 rtnl_fill_stats+0x47/0x880 net/core/rtnetlink.c:1268 rtnl_fill_ifinfo+0x18da/0x2270 net/core/rtnetlink.c:1909 rtmsg_ifinfo_build_skb+0x18a/0x260 net/core/rtnetlink.c:4079 rtmsg_ifinfo_event net/core/rtnetlink.c:4112 [inline] rtmsg_ifinfo+0x91/0x1b0 net/core/rtnetlink.c:4121 register_netdevice+0x1774/0x1b00 net/core/dev.c:10534 ppp_unit_register drivers/net/ppp/ppp_generic.c:1219 [inline] ppp_dev_configure+0x883/0xb10 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+0x797/0x1cd0 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+0xf9/0x170 fs/ioctl.c:893 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f IN-SOFTIRQ-W at: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x35/0x50 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:356 [inline] ppp_do_recv+0x38/0x26b0 drivers/net/ppp/ppp_generic.c:2210 ppp_input+0x5de/0xa10 drivers/net/ppp/ppp_generic.c:2327 ppp_async_process+0x7f/0x150 drivers/net/ppp/ppp_async.c:495 tasklet_action_common+0x321/0x4d0 kernel/softirq.c:784 handle_softirqs+0x2c5/0x980 kernel/softirq.c:554 __do_softirq kernel/softirq.c:588 [inline] invoke_softirq kernel/softirq.c:428 [inline] __irq_exit_rcu+0xf4/0x1c0 kernel/softirq.c:637 irq_exit_rcu+0x9/0x30 kernel/softirq.c:649 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1037 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1037 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 __tasklet_schedule_common+0x1fd/0x270 kernel/softirq.c:733 tasklet_schedule include/linux/interrupt.h:719 [inline] ppp_asynctty_receive+0x1ea6/0x2000 drivers/net/ppp/ppp_async.c:345 tty_ldisc_receive_buf+0x11f/0x170 drivers/tty/tty_buffer.c:391 tty_port_default_receive_buf+0x6d/0xa0 drivers/tty/tty_port.c:37 receive_buf drivers/tty/tty_buffer.c:445 [inline] flush_to_ldisc+0x328/0x860 drivers/tty/tty_buffer.c:495 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/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+0x1ed/0x550 kernel/locking/lockdep.c:5825 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x35/0x50 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:356 [inline] ppp_get_stats64+0x33/0x290 drivers/net/ppp/ppp_generic.c:1534 dev_get_stats+0xad/0xa00 net/core/dev.c:10937 rtnl_fill_stats+0x47/0x880 net/core/rtnetlink.c:1268 rtnl_fill_ifinfo+0x18da/0x2270 net/core/rtnetlink.c:1909 rtmsg_ifinfo_build_skb+0x18a/0x260 net/core/rtnetlink.c:4079 rtmsg_ifinfo_event net/core/rtnetlink.c:4112 [inline] rtmsg_ifinfo+0x91/0x1b0 net/core/rtnetlink.c:4121 register_netdevice+0x1774/0x1b00 net/core/dev.c:10534 ppp_unit_register drivers/net/ppp/ppp_generic.c:1219 [inline] ppp_dev_configure+0x883/0xb10 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+0x797/0x1cd0 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+0xf9/0x170 fs/ioctl.c:893 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f } ... key at: [] ppp_dev_configure.__key+0x0/0x20 ... acquired at: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x35/0x50 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:356 [inline] ppp_connect_channel+0x194/0x650 drivers/net/ppp/ppp_generic.c:3485 ppp_ioctl+0xdd4/0x1cd0 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+0xf9/0x170 fs/ioctl.c:893 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> (&pch->downl){+.+.}-{2:2} { HARDIRQ-ON-W at: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x35/0x50 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:356 [inline] ppp_unregister_channel+0x7c/0x300 drivers/net/ppp/ppp_generic.c:2992 pppox_unbind_sock+0x5c/0xb0 drivers/net/ppp/pppox.c:58 pppoe_release+0x16e/0x820 drivers/net/ppp/pppoe.c:584 __sock_release net/socket.c:658 [inline] sock_close+0xbc/0x240 net/socket.c:1426 __fput+0x23f/0x880 fs/file_table.c:431 task_work_run+0x24f/0x310 kernel/task_work.c:228 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0xa2f/0x28e0 kernel/exit.c:939 do_group_exit+0x207/0x2c0 kernel/exit.c:1088 get_signal+0x16a3/0x1740 kernel/signal.c:2917 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [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+0xc9/0x370 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f SOFTIRQ-ON-W at: lock_acquire+0x1ed/0x550 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+0x18b/0xa10 drivers/net/ppp/ppp_generic.c:2304 pppoe_rcv_core+0x117/0x310 drivers/net/ppp/pppoe.c:379 sk_backlog_rcv include/net/sock.h:1113 [inline] __release_sock+0x243/0x350 net/core/sock.c:3072 release_sock+0x61/0x1f0 net/core/sock.c:3626 pppoe_sendmsg+0xd5/0x750 drivers/net/ppp/pppoe.c:903 sock_sendmsg_nosec net/socket.c:729 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:744 ____sys_sendmsg+0x52a/0x7e0 net/socket.c:2602 ___sys_sendmsg net/socket.c:2656 [inline] __sys_sendmmsg+0x3ab/0x730 net/socket.c:2742 __do_sys_sendmmsg net/socket.c:2771 [inline] __se_sys_sendmmsg net/socket.c:2768 [inline] __x64_sys_sendmmsg+0xa0/0xb0 net/socket.c:2768 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f INITIAL USE at: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x35/0x50 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:356 [inline] ppp_unregister_channel+0x7c/0x300 drivers/net/ppp/ppp_generic.c:2992 pppox_unbind_sock+0x5c/0xb0 drivers/net/ppp/pppox.c:58 pppoe_release+0x16e/0x820 drivers/net/ppp/pppoe.c:584 __sock_release net/socket.c:658 [inline] sock_close+0xbc/0x240 net/socket.c:1426 __fput+0x23f/0x880 fs/file_table.c:431 task_work_run+0x24f/0x310 kernel/task_work.c:228 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0xa2f/0x28e0 kernel/exit.c:939 do_group_exit+0x207/0x2c0 kernel/exit.c:1088 get_signal+0x16a3/0x1740 kernel/signal.c:2917 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [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+0xc9/0x370 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f } ... key at: [] ppp_register_net_channel.__key.1+0x0/0x20 ... acquired at: mark_lock+0x223/0x360 kernel/locking/lockdep.c:4725 __lock_acquire+0x11b0/0x2050 kernel/locking/lockdep.c:5156 lock_acquire+0x1ed/0x550 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+0x18b/0xa10 drivers/net/ppp/ppp_generic.c:2304 pppoe_rcv_core+0x117/0x310 drivers/net/ppp/pppoe.c:379 sk_backlog_rcv include/net/sock.h:1113 [inline] __release_sock+0x243/0x350 net/core/sock.c:3072 release_sock+0x61/0x1f0 net/core/sock.c:3626 pppoe_sendmsg+0xd5/0x750 drivers/net/ppp/pppoe.c:903 sock_sendmsg_nosec net/socket.c:729 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:744 ____sys_sendmsg+0x52a/0x7e0 net/socket.c:2602 ___sys_sendmsg net/socket.c:2656 [inline] __sys_sendmmsg+0x3ab/0x730 net/socket.c:2742 __do_sys_sendmmsg net/socket.c:2771 [inline] __se_sys_sendmmsg net/socket.c:2768 [inline] __x64_sys_sendmmsg+0xa0/0xb0 net/socket.c:2768 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f stack backtrace: CPU: 0 UID: 0 PID: 8854 Comm: syz.1.709 Not tainted 6.12.0-rc1-syzkaller-00046-g7ec462100ef9 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_irq_inversion_bug+0x33d/0x390 kernel/locking/lockdep.c:4121 mark_lock_irq+0x867/0xc20 kernel/locking/lockdep.c:4283 mark_lock+0x223/0x360 kernel/locking/lockdep.c:4725 __lock_acquire+0x11b0/0x2050 kernel/locking/lockdep.c:5156 lock_acquire+0x1ed/0x550 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+0x18b/0xa10 drivers/net/ppp/ppp_generic.c:2304 pppoe_rcv_core+0x117/0x310 drivers/net/ppp/pppoe.c:379 sk_backlog_rcv include/net/sock.h:1113 [inline] __release_sock+0x243/0x350 net/core/sock.c:3072 release_sock+0x61/0x1f0 net/core/sock.c:3626 pppoe_sendmsg+0xd5/0x750 drivers/net/ppp/pppoe.c:903 sock_sendmsg_nosec net/socket.c:729 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:744 ____sys_sendmsg+0x52a/0x7e0 net/socket.c:2602 ___sys_sendmsg net/socket.c:2656 [inline] __sys_sendmmsg+0x3ab/0x730 net/socket.c:2742 __do_sys_sendmmsg net/socket.c:2771 [inline] __se_sys_sendmmsg net/socket.c:2768 [inline] __x64_sys_sendmmsg+0xa0/0xb0 net/socket.c:2768 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f28e017dff9 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:00007f28e0f4f038 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 00007f28e0335f80 RCX: 00007f28e017dff9 RDX: 0400000000000026 RSI: 0000000020001cc0 RDI: 0000000000000005 RBP: 00007f28e01f0296 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f28e0335f80 R15: 00007f28e045fa28