===================================================== WARNING: SOFTIRQ-READ-safe -> SOFTIRQ-READ-unsafe lock order detected 6.12.0-rc1-syzkaller #0 Not tainted ----------------------------------------------------- syz.0.1898/18344 [HC0[0]:SC0[4]:HE1:SE0] is trying to acquire: ffff88806799ce10 (&ppp->rlock){+...}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] ffff88806799ce10 (&ppp->rlock){+...}-{2:2}, at: ppp_disconnect_channel+0x9a/0x2d0 drivers/net/ppp/ppp_generic.c:3528 and this task is already holding: ffff88806799ce50 (&ppp->wlock){+...}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] ffff88806799ce50 (&ppp->wlock){+...}-{2:2}, at: ppp_disconnect_channel+0x88/0x2d0 drivers/net/ppp/ppp_generic.c:3528 which would create a new lock dependency: (&ppp->wlock){+...}-{2:2} -> (&ppp->rlock){+...}-{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+0x1ed/0x550 kernel/locking/lockdep.c:5825 __raw_read_lock_bh include/linux/rwlock_api_smp.h:176 [inline] _raw_read_lock_bh+0x3d/0x50 kernel/locking/spinlock.c:252 ppp_input+0x3dc/0xa10 drivers/net/ppp/ppp_generic.c:2307 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 run_ksoftirqd+0xca/0x130 kernel/softirq.c:927 smpboot_thread_fn+0x544/0xa30 kernel/smpboot.c:164 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 to a SOFTIRQ-READ-irq-unsafe lock: (&pch->downl){+.+.}-{2:2} ... which became SOFTIRQ-READ-irq-unsafe 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 other info that might help us debug this: Chain exists of: &pch->upl --> &ppp->wlock --> &pch->downl Possible interrupt unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&pch->downl); local_irq_disable(); lock(&pch->upl); lock(&ppp->wlock); lock(&pch->upl); *** DEADLOCK *** 3 locks held by syz.0.1898/18344: #0: ffff8880294080a0 (&tty->ldisc_sem){++++}-{0:0}, at: __tty_ldisc_lock drivers/tty/tty_ldisc.c:289 [inline] #0: ffff8880294080a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_lock_pair_timeout drivers/tty/tty_ldisc.c:345 [inline] #0: ffff8880294080a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_lock_pair drivers/tty/tty_ldisc.c:366 [inline] #0: ffff8880294080a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_release+0xb7/0x200 drivers/tty/tty_ldisc.c:780 #1: ffff88802940e0a0 (&tty->ldisc_sem/1){+.+.}-{0:0}, at: __tty_ldisc_lock_nested drivers/tty/tty_ldisc.c:295 [inline] #1: ffff88802940e0a0 (&tty->ldisc_sem/1){+.+.}-{0:0}, at: tty_ldisc_lock_pair_timeout drivers/tty/tty_ldisc.c:347 [inline] #1: ffff88802940e0a0 (&tty->ldisc_sem/1){+.+.}-{0:0}, at: tty_ldisc_lock_pair drivers/tty/tty_ldisc.c:366 [inline] #1: ffff88802940e0a0 (&tty->ldisc_sem/1){+.+.}-{0:0}, at: tty_ldisc_release+0xdb/0x200 drivers/tty/tty_ldisc.c:780 #2: ffff88806799ce50 (&ppp->wlock){+...}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] #2: ffff88806799ce50 (&ppp->wlock){+...}-{2:2}, at: ppp_disconnect_channel+0x88/0x2d0 drivers/net/ppp/ppp_generic.c:3528 the dependencies between SOFTIRQ-READ-irq-safe lock and the holding lock: -> (&pch->upl){++.-}-{2:2} { HARDIRQ-ON-W at: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825 __raw_write_lock_bh include/linux/rwlock_api_smp.h:202 [inline] _raw_write_lock_bh+0x35/0x50 kernel/locking/spinlock.c:334 ppp_disconnect_channel+0x2f/0x2d0 drivers/net/ppp/ppp_generic.c:3522 ppp_unregister_channel+0xb9/0x300 drivers/net/ppp/ppp_generic.c:2996 ppp_asynctty_close+0xf8/0x190 drivers/net/ppp/ppp_async.c:238 tty_ldisc_kill+0xa3/0x1a0 drivers/tty/tty_ldisc.c:613 tty_ldisc_release+0x1a1/0x200 drivers/tty/tty_ldisc.c:781 tty_release_struct+0x2b/0xe0 drivers/tty/tty_io.c:1690 tty_release+0xd06/0x12c0 drivers/tty/tty_io.c:1861 __fput+0x23f/0x880 fs/file_table.c:431 task_work_run+0x24f/0x310 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+0x168/0x370 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f HARDIRQ-ON-R at: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825 __raw_read_lock_bh include/linux/rwlock_api_smp.h:176 [inline] _raw_read_lock_bh+0x3d/0x50 kernel/locking/spinlock.c:252 ppp_input+0x3dc/0xa10 drivers/net/ppp/ppp_generic.c:2307 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 IN-SOFTIRQ-R at: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825 __raw_read_lock_bh include/linux/rwlock_api_smp.h:176 [inline] _raw_read_lock_bh+0x3d/0x50 kernel/locking/spinlock.c:252 ppp_input+0x3dc/0xa10 drivers/net/ppp/ppp_generic.c:2307 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 run_ksoftirqd+0xca/0x130 kernel/softirq.c:927 smpboot_thread_fn+0x544/0xa30 kernel/smpboot.c:164 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_write_lock_bh include/linux/rwlock_api_smp.h:202 [inline] _raw_write_lock_bh+0x35/0x50 kernel/locking/spinlock.c:334 ppp_disconnect_channel+0x2f/0x2d0 drivers/net/ppp/ppp_generic.c:3522 ppp_unregister_channel+0xb9/0x300 drivers/net/ppp/ppp_generic.c:2996 ppp_asynctty_close+0xf8/0x190 drivers/net/ppp/ppp_async.c:238 tty_ldisc_kill+0xa3/0x1a0 drivers/tty/tty_ldisc.c:613 tty_ldisc_release+0x1a1/0x200 drivers/tty/tty_ldisc.c:781 tty_release_struct+0x2b/0xe0 drivers/tty/tty_io.c:1690 tty_release+0xd06/0x12c0 drivers/tty/tty_io.c:1861 __fput+0x23f/0x880 fs/file_table.c:431 task_work_run+0x24f/0x310 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+0x168/0x370 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f INITIAL READ USE at: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825 __raw_read_lock_bh include/linux/rwlock_api_smp.h:176 [inline] _raw_read_lock_bh+0x3d/0x50 kernel/locking/spinlock.c:252 ppp_input+0x3dc/0xa10 drivers/net/ppp/ppp_generic.c:2307 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 } ... key at: [] ppp_register_net_channel.__key.3+0x0/0x20 -> (&ppp->wlock){+...}-{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+0xc3/0x290 drivers/net/ppp/ppp_generic.c:1539 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 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+0xc3/0x290 drivers/net/ppp/ppp_generic.c:1539 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.67+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+0x174/0x650 drivers/net/ppp/ppp_generic.c:3484 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 the dependencies between the lock to be acquired and SOFTIRQ-READ-irq-unsafe lock: -> (&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 ppp_asynctty_close+0xf8/0x190 drivers/net/ppp/ppp_async.c:238 tty_ldisc_kill+0xa3/0x1a0 drivers/tty/tty_ldisc.c:613 tty_ldisc_release+0x1a1/0x200 drivers/tty/tty_ldisc.c:781 tty_release_struct+0x2b/0xe0 drivers/tty/tty_io.c:1690 tty_release+0xd06/0x12c0 drivers/tty/tty_io.c:1861 __fput+0x23f/0x880 fs/file_table.c:431 task_work_run+0x24f/0x310 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+0x168/0x370 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 ppp_asynctty_close+0xf8/0x190 drivers/net/ppp/ppp_async.c:238 tty_ldisc_kill+0xa3/0x1a0 drivers/tty/tty_ldisc.c:613 tty_ldisc_release+0x1a1/0x200 drivers/tty/tty_ldisc.c:781 tty_release_struct+0x2b/0xe0 drivers/tty/tty_io.c:1690 tty_release+0xd06/0x12c0 drivers/tty/tty_io.c:1861 __fput+0x23f/0x880 fs/file_table.c:431 task_work_run+0x24f/0x310 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+0x168/0x370 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: 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 -> (&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 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_disconnect_channel+0x9a/0x2d0 drivers/net/ppp/ppp_generic.c:3528 ppp_unregister_channel+0xb9/0x300 drivers/net/ppp/ppp_generic.c:2996 ppp_asynctty_close+0xf8/0x190 drivers/net/ppp/ppp_async.c:238 tty_ldisc_kill+0xa3/0x1a0 drivers/tty/tty_ldisc.c:613 tty_ldisc_release+0x1a1/0x200 drivers/tty/tty_ldisc.c:781 tty_release_struct+0x2b/0xe0 drivers/tty/tty_io.c:1690 tty_release+0xd06/0x12c0 drivers/tty/tty_io.c:1861 __fput+0x23f/0x880 fs/file_table.c:431 task_work_run+0x24f/0x310 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+0x168/0x370 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f stack backtrace: CPU: 0 UID: 0 PID: 18344 Comm: syz.0.1898 Not tainted 6.12.0-rc1-syzkaller #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_bad_irq_dependency kernel/locking/lockdep.c:2647 [inline] check_irq_usage kernel/locking/lockdep.c:2888 [inline] check_prev_add kernel/locking/lockdep.c:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3280 [inline] validate_chain+0x4ebd/0x5920 kernel/locking/lockdep.c:3904 __lock_acquire+0x1384/0x2050 kernel/locking/lockdep.c:5202 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_disconnect_channel+0x9a/0x2d0 drivers/net/ppp/ppp_generic.c:3528 ppp_unregister_channel+0xb9/0x300 drivers/net/ppp/ppp_generic.c:2996 ppp_asynctty_close+0xf8/0x190 drivers/net/ppp/ppp_async.c:238 tty_ldisc_kill+0xa3/0x1a0 drivers/tty/tty_ldisc.c:613 tty_ldisc_release+0x1a1/0x200 drivers/tty/tty_ldisc.c:781 tty_release_struct+0x2b/0xe0 drivers/tty/tty_io.c:1690 tty_release+0xd06/0x12c0 drivers/tty/tty_io.c:1861 __fput+0x23f/0x880 fs/file_table.c:431 task_work_run+0x24f/0x310 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+0x168/0x370 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd5f017dff9 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:00007fd5f045fb88 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007fd5f0337a80 RCX: 00007fd5f017dff9 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007fd5f0337a80 R08: 0000000000000006 R09: 00007fd5f045fe7f R10: 00000000005ef510 R11: 0000000000000246 R12: 00000000000feddf R13: 00007fd5f045fc90 R14: 0000000000000032 R15: ffffffffffffffff