======================================================== WARNING: possible irq lock inversion dependency detected 5.6.0-syzkaller #0 Not tainted -------------------------------------------------------- syz-executor.1/8599 just changed the state of lock: ffff888041d85cd8 (&ctx->ctx_lock){..-.}-{2:2}, at: spin_lock_irq include/linux/spinlock.h:378 [inline] ffff888041d85cd8 (&ctx->ctx_lock){..-.}-{2:2}, at: free_ioctx_users+0x30/0x1c0 fs/aio.c:618 but this lock took another, SOFTIRQ-unsafe lock in the past: (&pid->wait_pidfd){+.+.}-{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(&pid->wait_pidfd); local_irq_disable(); lock(&ctx->ctx_lock); lock(&pid->wait_pidfd); lock(&ctx->ctx_lock); *** DEADLOCK *** 3 locks held by syz-executor.1/8599: #0: ffffffff895aaa18 (rtnl_mutex){+.+.}-{3:3}, at: dev_ioctl+0x4c3/0xc70 net/core/dev_ioctl.c:495 #1: ffffffff892e6be0 (rcu_callback){....}-{0:0}, at: rcu_lock_acquire+0x0/0x30 lib/xarray.c:75 #2: ffffffff892e6b90 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:207 the shortest dependencies between 2nd lock and 1st lock: -> (&pid->wait_pidfd){+.+.}-{2:2} { HARDIRQ-ON-W at: lock_acquire+0x169/0x480 kernel/locking/lockdep.c:4923 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:151 spin_lock include/linux/spinlock.h:353 [inline] proc_pid_make_inode+0x187/0x2d0 fs/proc/base.c:1880 proc_pid_instantiate+0x4b/0x1a0 fs/proc/base.c:3285 proc_pid_lookup+0x218/0x2f0 fs/proc/base.c:3320 proc_root_lookup+0x1b/0x50 fs/proc/root.c:243 __lookup_slow+0x240/0x370 fs/namei.c:1530 lookup_slow fs/namei.c:1547 [inline] walk_component+0x442/0x680 fs/namei.c:1846 link_path_walk+0x66d/0xba0 fs/namei.c:2165 path_openat+0x21d/0x38b0 fs/namei.c:3342 do_filp_open+0x191/0x3a0 fs/namei.c:3373 do_sys_openat2+0x463/0x770 fs/open.c:1148 do_sys_open fs/open.c:1164 [inline] ksys_open include/linux/syscalls.h:1386 [inline] __do_sys_open fs/open.c:1170 [inline] __se_sys_open fs/open.c:1168 [inline] __x64_sys_open+0x1af/0x1e0 fs/open.c:1168 do_syscall_64+0xf3/0x1b0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 SOFTIRQ-ON-W at: lock_acquire+0x169/0x480 kernel/locking/lockdep.c:4923 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:151 spin_lock include/linux/spinlock.h:353 [inline] proc_pid_make_inode+0x187/0x2d0 fs/proc/base.c:1880 proc_pid_instantiate+0x4b/0x1a0 fs/proc/base.c:3285 proc_pid_lookup+0x218/0x2f0 fs/proc/base.c:3320 proc_root_lookup+0x1b/0x50 fs/proc/root.c:243 __lookup_slow+0x240/0x370 fs/namei.c:1530 lookup_slow fs/namei.c:1547 [inline] walk_component+0x442/0x680 fs/namei.c:1846 link_path_walk+0x66d/0xba0 fs/namei.c:2165 path_openat+0x21d/0x38b0 fs/namei.c:3342 do_filp_open+0x191/0x3a0 fs/namei.c:3373 do_sys_openat2+0x463/0x770 fs/open.c:1148 do_sys_open fs/open.c:1164 [inline] ksys_open include/linux/syscalls.h:1386 [inline] __do_sys_open fs/open.c:1170 [inline] __se_sys_open fs/open.c:1168 [inline] __x64_sys_open+0x1af/0x1e0 fs/open.c:1168 do_syscall_64+0xf3/0x1b0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 INITIAL USE at: lock_acquire+0x169/0x480 kernel/locking/lockdep.c:4923 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x9e/0xc0 kernel/locking/spinlock.c:159 __wake_up_common_lock kernel/sched/wait.c:122 [inline] __wake_up+0xb8/0x150 kernel/sched/wait.c:142 do_notify_pidfd kernel/signal.c:1900 [inline] do_notify_parent+0x167/0xce0 kernel/signal.c:1927 exit_notify kernel/exit.c:660 [inline] do_exit+0x12c5/0x1f80 kernel/exit.c:816 call_usermodehelper_exec_async+0x47c/0x480 kernel/umh.c:125 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 } ... key at: [] alloc_pid.__key+0x0/0x10 ... acquired at: lock_acquire+0x169/0x480 kernel/locking/lockdep.c:4923 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:151 spin_lock include/linux/spinlock.h:353 [inline] aio_poll fs/aio.c:1767 [inline] __io_submit_one fs/aio.c:1841 [inline] io_submit_one+0x10f5/0x1a80 fs/aio.c:1878 __do_sys_io_submit fs/aio.c:1937 [inline] __se_sys_io_submit+0x117/0x220 fs/aio.c:1907 do_syscall_64+0xf3/0x1b0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 -> (&ctx->ctx_lock){..-.}-{2:2} { IN-SOFTIRQ-W at: lock_acquire+0x169/0x480 kernel/locking/lockdep.c:4923 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:128 [inline] _raw_spin_lock_irq+0x67/0x80 kernel/locking/spinlock.c:167 spin_lock_irq include/linux/spinlock.h:378 [inline] free_ioctx_users+0x30/0x1c0 fs/aio.c:618 percpu_ref_put_many include/linux/percpu-refcount.h:309 [inline] percpu_ref_put+0x18d/0x1a0 include/linux/percpu-refcount.h:325 rcu_do_batch kernel/rcu/tree.c:2206 [inline] rcu_core+0x816/0x1120 kernel/rcu/tree.c:2433 __do_softirq+0x268/0x80c kernel/softirq.c:292 do_softirq_own_stack+0x2a/0x40 arch/x86/entry/entry_64.S:1082 do_softirq+0xf9/0x190 kernel/softirq.c:337 __local_bh_enable_ip+0x18b/0x230 kernel/softirq.c:189 get_next_corpse net/netfilter/nf_conntrack_core.c:2150 [inline] nf_ct_iterate_cleanup+0x307/0x3a0 net/netfilter/nf_conntrack_core.c:2173 nf_ct_iterate_cleanup_net+0xfc/0x150 net/netfilter/nf_conntrack_core.c:2258 masq_device_event+0x9b/0xd0 net/netfilter/nf_nat_masquerade.c:88 notifier_call_chain kernel/notifier.c:83 [inline] __raw_notifier_call_chain kernel/notifier.c:361 [inline] raw_notifier_call_chain+0xd4/0x170 kernel/notifier.c:368 __dev_notify_flags+0x253/0x4d0 net/core/dev.c:1948 dev_change_flags+0xe3/0x190 net/core/dev.c:8219 dev_ifsioc+0xb6/0x950 net/core/dev_ioctl.c:244 dev_ioctl+0x4d1/0xc70 net/core/dev_ioctl.c:496 sock_do_ioctl+0x169/0x260 net/socket.c:1076 sock_ioctl+0x4aa/0x690 net/socket.c:1204 vfs_ioctl fs/ioctl.c:47 [inline] ksys_ioctl fs/ioctl.c:763 [inline] __do_sys_ioctl fs/ioctl.c:772 [inline] __se_sys_ioctl+0xf9/0x160 fs/ioctl.c:770 do_syscall_64+0xf3/0x1b0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 INITIAL USE at: lock_acquire+0x169/0x480 kernel/locking/lockdep.c:4923 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:128 [inline] _raw_spin_lock_irq+0x67/0x80 kernel/locking/spinlock.c:167 spin_lock_irq include/linux/spinlock.h:378 [inline] aio_poll fs/aio.c:1765 [inline] __io_submit_one fs/aio.c:1841 [inline] io_submit_one+0x10cb/0x1a80 fs/aio.c:1878 __do_sys_io_submit fs/aio.c:1937 [inline] __se_sys_io_submit+0x117/0x220 fs/aio.c:1907 do_syscall_64+0xf3/0x1b0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 } ... key at: [] ioctx_alloc.__key+0x0/0x10 ... acquired at: mark_lock_irq kernel/locking/lockdep.c:3585 [inline] mark_lock+0x529/0x1b00 kernel/locking/lockdep.c:3935 mark_usage kernel/locking/lockdep.c:3834 [inline] __lock_acquire+0xaa7/0x2b90 kernel/locking/lockdep.c:4298 lock_acquire+0x169/0x480 kernel/locking/lockdep.c:4923 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:128 [inline] _raw_spin_lock_irq+0x67/0x80 kernel/locking/spinlock.c:167 spin_lock_irq include/linux/spinlock.h:378 [inline] free_ioctx_users+0x30/0x1c0 fs/aio.c:618 percpu_ref_put_many include/linux/percpu-refcount.h:309 [inline] percpu_ref_put+0x18d/0x1a0 include/linux/percpu-refcount.h:325 rcu_do_batch kernel/rcu/tree.c:2206 [inline] rcu_core+0x816/0x1120 kernel/rcu/tree.c:2433 __do_softirq+0x268/0x80c kernel/softirq.c:292 do_softirq_own_stack+0x2a/0x40 arch/x86/entry/entry_64.S:1082 do_softirq+0xf9/0x190 kernel/softirq.c:337 __local_bh_enable_ip+0x18b/0x230 kernel/softirq.c:189 get_next_corpse net/netfilter/nf_conntrack_core.c:2150 [inline] nf_ct_iterate_cleanup+0x307/0x3a0 net/netfilter/nf_conntrack_core.c:2173 nf_ct_iterate_cleanup_net+0xfc/0x150 net/netfilter/nf_conntrack_core.c:2258 masq_device_event+0x9b/0xd0 net/netfilter/nf_nat_masquerade.c:88 notifier_call_chain kernel/notifier.c:83 [inline] __raw_notifier_call_chain kernel/notifier.c:361 [inline] raw_notifier_call_chain+0xd4/0x170 kernel/notifier.c:368 __dev_notify_flags+0x253/0x4d0 net/core/dev.c:1948 dev_change_flags+0xe3/0x190 net/core/dev.c:8219 dev_ifsioc+0xb6/0x950 net/core/dev_ioctl.c:244 dev_ioctl+0x4d1/0xc70 net/core/dev_ioctl.c:496 sock_do_ioctl+0x169/0x260 net/socket.c:1076 sock_ioctl+0x4aa/0x690 net/socket.c:1204 vfs_ioctl fs/ioctl.c:47 [inline] ksys_ioctl fs/ioctl.c:763 [inline] __do_sys_ioctl fs/ioctl.c:772 [inline] __se_sys_ioctl+0xf9/0x160 fs/ioctl.c:770 do_syscall_64+0xf3/0x1b0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 stack backtrace: CPU: 0 PID: 8599 Comm: syz-executor.1 Not tainted 5.6.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1e9/0x30e lib/dump_stack.c:118 print_irq_inversion_bug+0xb67/0xe90 kernel/locking/lockdep.c:3447 check_usage_forwards+0x13f/0x240 kernel/locking/lockdep.c:3472 mark_lock_irq kernel/locking/lockdep.c:3585 [inline] mark_lock+0x529/0x1b00 kernel/locking/lockdep.c:3935 mark_usage kernel/locking/lockdep.c:3834 [inline] __lock_acquire+0xaa7/0x2b90 kernel/locking/lockdep.c:4298 lock_acquire+0x169/0x480 kernel/locking/lockdep.c:4923 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:128 [inline] _raw_spin_lock_irq+0x67/0x80 kernel/locking/spinlock.c:167 spin_lock_irq include/linux/spinlock.h:378 [inline] free_ioctx_users+0x30/0x1c0 fs/aio.c:618 percpu_ref_put_many include/linux/percpu-refcount.h:309 [inline] percpu_ref_put+0x18d/0x1a0 include/linux/percpu-refcount.h:325 rcu_do_batch kernel/rcu/tree.c:2206 [inline] rcu_core+0x816/0x1120 kernel/rcu/tree.c:2433 __do_softirq+0x268/0x80c kernel/softirq.c:292 do_softirq_own_stack+0x2a/0x40 arch/x86/entry/entry_64.S:1082 do_softirq+0xf9/0x190 kernel/softirq.c:337 __local_bh_enable_ip+0x18b/0x230 kernel/softirq.c:189 get_next_corpse net/netfilter/nf_conntrack_core.c:2150 [inline] nf_ct_iterate_cleanup+0x307/0x3a0 net/netfilter/nf_conntrack_core.c:2173 nf_ct_iterate_cleanup_net+0xfc/0x150 net/netfilter/nf_conntrack_core.c:2258 masq_device_event+0x9b/0xd0 net/netfilter/nf_nat_masquerade.c:88 notifier_call_chain kernel/notifier.c:83 [inline] __raw_notifier_call_chain kernel/notifier.c:361 [inline] raw_notifier_call_chain+0xd4/0x170 kernel/notifier.c:368 __dev_notify_flags+0x253/0x4d0 net/core/dev.c:1948 dev_change_flags+0xe3/0x190 net/core/dev.c:8219 dev_ifsioc+0xb6/0x950 net/core/dev_ioctl.c:244 dev_ioctl+0x4d1/0xc70 net/core/dev_ioctl.c:496 sock_do_ioctl+0x169/0x260 net/socket.c:1076 sock_ioctl+0x4aa/0x690 net/socket.c:1204 vfs_ioctl fs/ioctl.c:47 [inline] ksys_ioctl fs/ioctl.c:763 [inline] __do_sys_ioctl fs/ioctl.c:772 [inline] __se_sys_ioctl+0xf9/0x160 fs/ioctl.c:770 do_syscall_64+0xf3/0x1b0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x45c889 Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fb842d61c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fb842d626d4 RCX: 000000000045c889 RDX: 0000000020000040 RSI: 0000000000008914 RDI: 0000000000000004 RBP: 000000000076bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000416 R14: 00000000004d3720 R15: 000000000076bf0c