Hello, syzbot found the following issue on: HEAD commit: d42f7708e27c Merge tag 'for-linus-6.11' of git://git.kerne.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=17d057c7980000 kernel config: https://syzkaller.appspot.com/x/.config?x=61d235cb8d15001c dashboard link: https://syzkaller.appspot.com/bug?extid=38ad8c7c6638c5381a47 compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/a36d838567fc/disk-d42f7708.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/84e3541e98ef/vmlinux-d42f7708.xz kernel image: https://storage.googleapis.com/syzbot-assets/1186c70ee3e0/bzImage-d42f7708.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+38ad8c7c6638c5381a47@xxxxxxxxxxxxxxxxxxxxxxxxx ===================================================== WARNING: SOFTIRQ-READ-safe -> SOFTIRQ-READ-unsafe lock order detected 6.11.0-rc7-syzkaller-00151-gd42f7708e27c #0 Not tainted ----------------------------------------------------- syz.2.1597/12167 [HC0[0]:SC0[8]:HE1:SE0] is trying to acquire: ffff8880635c39e0 (&pch->downl){+.+.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] ffff8880635c39e0 (&pch->downl){+.+.}-{2:2}, at: ppp_connect_channel+0x194/0x650 drivers/net/ppp/ppp_generic.c:3485 and this task is already holding: ffff888078e3ee10 (&ppp->rlock){+...}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] ffff888078e3ee10 (&ppp->rlock){+...}-{2:2}, at: ppp_connect_channel+0x185/0x650 drivers/net/ppp/ppp_generic.c:3484 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+0x1ed/0x550 kernel/locking/lockdep.c:5759 __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_sync_process+0x71/0x160 drivers/net/ppp/ppp_synctty.c:490 tasklet_action_common+0x323/0x4d0 kernel/softirq.c:785 handle_softirqs+0x2c6/0x970 kernel/softirq.c:554 run_ksoftirqd+0xca/0x130 kernel/softirq.c:928 smpboot_thread_fn+0x546/0xa30 kernel/smpboot.c:164 kthread+0x2f2/0x390 kernel/kthread.c:389 ret_from_fork+0x4d/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:5759 __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:1111 [inline] __release_sock+0x245/0x350 net/core/sock.c:3004 release_sock+0x61/0x1f0 net/core/sock.c:3558 pppoe_sendmsg+0xd5/0x750 drivers/net/ppp/pppoe.c:903 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0x223/0x270 net/socket.c:745 ____sys_sendmsg+0x525/0x7d0 net/socket.c:2597 ___sys_sendmsg net/socket.c:2651 [inline] __sys_sendmmsg+0x3b2/0x740 net/socket.c:2737 __do_sys_sendmmsg net/socket.c:2766 [inline] __se_sys_sendmmsg net/socket.c:2763 [inline] __x64_sys_sendmmsg+0xa0/0xb0 net/socket.c:2763 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->rlock --> &pch->downl Possible interrupt unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&pch->downl); local_irq_disable(); lock(&pch->upl); lock(&ppp->rlock); <Interrupt> lock(&pch->upl); *** DEADLOCK *** 5 locks held by syz.2.1597/12167: #0: ffffffff8f4700a8 (ppp_mutex){+.+.}-{3:3}, at: ppp_ioctl+0x112/0x1cd0 drivers/net/ppp/ppp_generic.c:729 #1: ffff888057470cc0 (&pn->all_ppp_mutex){+.+.}-{3:3}, at: ppp_connect_channel+0x5e/0x650 drivers/net/ppp/ppp_generic.c:3474 #2: ffff8880635c3a48 (&pch->upl){++.-}-{2:2}, at: ppp_connect_channel+0x87/0x650 drivers/net/ppp/ppp_generic.c:3478 #3: ffff888078e3ee50 (&ppp->wlock){+...}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] #3: ffff888078e3ee50 (&ppp->wlock){+...}-{2:2}, at: ppp_connect_channel+0x174/0x650 drivers/net/ppp/ppp_generic.c:3484 #4: ffff888078e3ee10 (&ppp->rlock){+...}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] #4: ffff888078e3ee10 (&ppp->rlock){+...}-{2:2}, at: ppp_connect_channel+0x185/0x650 drivers/net/ppp/ppp_generic.c:3484 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:5759 __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 pppox_unbind_sock+0x5c/0xb0 drivers/net/ppp/pppox.c:58 pppol2tp_release+0x99/0x340 net/l2tp/l2tp_ppp.c:438 __sock_release net/socket.c:659 [inline] sock_close+0xbe/0x240 net/socket.c:1421 __fput+0x24c/0x8a0 fs/file_table.c:422 task_work_run+0x251/0x310 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:5759 __raw_read_lock_bh include/linux/rwlock_api_smp.h:176 [inline] _raw_read_lock_bh+0x3d/0x50 kernel/locking/spinlock.c:252 ppp_channel_push+0x2c/0x220 drivers/net/ppp/ppp_generic.c:2186 ppp_write+0x2b3/0x3f0 drivers/net/ppp/ppp_generic.c:540 vfs_write+0x2a4/0xc90 fs/read_write.c:588 ksys_write+0x1a0/0x2c0 fs/read_write.c:643 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:5759 __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_sync_process+0x71/0x160 drivers/net/ppp/ppp_synctty.c:490 tasklet_action_common+0x323/0x4d0 kernel/softirq.c:785 handle_softirqs+0x2c6/0x970 kernel/softirq.c:554 run_ksoftirqd+0xca/0x130 kernel/softirq.c:928 smpboot_thread_fn+0x546/0xa30 kernel/smpboot.c:164 kthread+0x2f2/0x390 kernel/kthread.c:389 ret_from_fork+0x4d/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:5759 __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 pppox_unbind_sock+0x5c/0xb0 drivers/net/ppp/pppox.c:58 pppol2tp_release+0x99/0x340 net/l2tp/l2tp_ppp.c:438 __sock_release net/socket.c:659 [inline] sock_close+0xbe/0x240 net/socket.c:1421 __fput+0x24c/0x8a0 fs/file_table.c:422 task_work_run+0x251/0x310 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:5759 __raw_read_lock_bh include/linux/rwlock_api_smp.h:176 [inline] _raw_read_lock_bh+0x3d/0x50 kernel/locking/spinlock.c:252 ppp_channel_push+0x2c/0x220 drivers/net/ppp/ppp_generic.c:2186 ppp_write+0x2b3/0x3f0 drivers/net/ppp/ppp_generic.c:540 vfs_write+0x2a4/0xc90 fs/read_write.c:588 ksys_write+0x1a0/0x2c0 fs/read_write.c:643 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: [<ffffffff9a68b1a0>] ppp_register_net_channel.__key.3+0x0/0x20 -> (&ppp->wlock){+...}-{2:2} { HARDIRQ-ON-W at: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759 __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+0xaf/0xa00 net/core/dev.c:10894 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:4113 [inline] rtmsg_ifinfo+0x91/0x1b0 net/core/rtnetlink.c:4122 register_netdevice+0x1774/0x1b00 net/core/dev.c:10491 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+0x799/0x1cd0 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+0xfe/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:5759 __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+0xaf/0xa00 net/core/dev.c:10894 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:4113 [inline] rtmsg_ifinfo+0x91/0x1b0 net/core/rtnetlink.c:4122 register_netdevice+0x1774/0x1b00 net/core/dev.c:10491 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+0x799/0x1cd0 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+0xfe/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: [<ffffffff9a68b2c0>] ppp_dev_configure.__key.67+0x0/0x20 ... acquired at: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759 __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+0xdd6/0x1cd0 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+0xfe/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:5759 __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+0xaf/0xa00 net/core/dev.c:10894 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:4113 [inline] rtmsg_ifinfo+0x91/0x1b0 net/core/rtnetlink.c:4122 register_netdevice+0x1774/0x1b00 net/core/dev.c:10491 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+0x799/0x1cd0 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+0xfe/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:5759 __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+0xaf/0xa00 net/core/dev.c:10894 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:4113 [inline] rtmsg_ifinfo+0x91/0x1b0 net/core/rtnetlink.c:4122 register_netdevice+0x1774/0x1b00 net/core/dev.c:10491 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+0x799/0x1cd0 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+0xfe/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: [<ffffffff9a68b2a0>] ppp_dev_configure.__key+0x0/0x20 ... acquired at: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759 __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_ioctl+0x121b/0x1cd0 drivers/net/ppp/ppp_generic.c:944 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl+0xfe/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:5759 __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 pppol2tp_release+0x99/0x340 net/l2tp/l2tp_ppp.c:438 __sock_release net/socket.c:659 [inline] sock_close+0xbe/0x240 net/socket.c:1421 __fput+0x24c/0x8a0 fs/file_table.c:422 task_work_run+0x251/0x310 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:5759 __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:1111 [inline] __release_sock+0x245/0x350 net/core/sock.c:3004 release_sock+0x61/0x1f0 net/core/sock.c:3558 pppoe_sendmsg+0xd5/0x750 drivers/net/ppp/pppoe.c:903 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0x223/0x270 net/socket.c:745 ____sys_sendmsg+0x525/0x7d0 net/socket.c:2597 ___sys_sendmsg net/socket.c:2651 [inline] __sys_sendmmsg+0x3b2/0x740 net/socket.c:2737 __do_sys_sendmmsg net/socket.c:2766 [inline] __se_sys_sendmmsg net/socket.c:2763 [inline] __x64_sys_sendmmsg+0xa0/0xb0 net/socket.c:2763 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:5759 __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 pppol2tp_release+0x99/0x340 net/l2tp/l2tp_ppp.c:438 __sock_release net/socket.c:659 [inline] sock_close+0xbe/0x240 net/socket.c:1421 __fput+0x24c/0x8a0 fs/file_table.c:422 task_work_run+0x251/0x310 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: [<ffffffff9a68b180>] ppp_register_net_channel.__key.1+0x0/0x20 ... acquired at: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759 __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+0xdd6/0x1cd0 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+0xfe/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 stack backtrace: CPU: 0 UID: 0 PID: 12167 Comm: syz.2.1597 Not tainted 6.11.0-rc7-syzkaller-00151-gd42f7708e27c #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 Call Trace: <TASK> __dump_stack lib/dump_stack.c:93 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119 print_bad_irq_dependency kernel/locking/lockdep.c:2625 [inline] check_irq_usage kernel/locking/lockdep.c:2864 [inline] check_prev_add kernel/locking/lockdep.c:3137 [inline] check_prevs_add kernel/locking/lockdep.c:3252 [inline] validate_chain+0x4de0/0x5900 kernel/locking/lockdep.c:3868 __lock_acquire+0x137a/0x2040 kernel/locking/lockdep.c:5142 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759 __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+0xdd6/0x1cd0 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+0xfe/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 RIP: 0033:0x7f8e1bb7def9 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:00007f8e1c9fd038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f8e1bd36208 RCX: 00007f8e1bb7def9 RDX: 0000000020000300 RSI: 000000004004743a RDI: 0000000000000005 RBP: 00007f8e1bbf0b76 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007f8e1bd36208 R15: 00007ffee62b5158 </TASK> --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. If the report is already addressed, let syzbot know by replying with: #syz fix: exact-commit-title If you want to overwrite report's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the report is a duplicate of another one, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup