====================================================== WARNING: possible circular locking dependency detected 4.14.266-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor191/8185 is trying to acquire lock: (&qdisc_rx_lock){+.-.}, at: [] spin_lock include/linux/spinlock.h:317 [inline] (&qdisc_rx_lock){+.-.}, at: [] pie_timer+0x6b/0x630 net/sched/sch_pie.c:431 but task is already holding lock: (((&q->adapt_timer))){+.-.}, at: [] lockdep_copy_map include/linux/lockdep.h:174 [inline] (((&q->adapt_timer))){+.-.}, at: [] call_timer_fn+0xb8/0x650 kernel/time/timer.c:1270 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (((&q->adapt_timer))){+.-.}: del_timer_sync+0xaf/0x240 kernel/time/timer.c:1236 qdisc_destroy+0x13c/0x310 net/sched/sch_generic.c:726 sfb_change+0x27a/0xa20 net/sched/sch_sfb.c:525 qdisc_change net/sched/sch_api.c:1145 [inline] tc_modify_qdisc+0xd4e/0x1250 net/sched/sch_api.c:1411 rtnetlink_rcv_msg+0x3be/0xb10 net/core/rtnetlink.c:4322 netlink_rcv_skb+0x125/0x390 net/netlink/af_netlink.c:2446 netlink_unicast_kernel net/netlink/af_netlink.c:1294 [inline] netlink_unicast+0x437/0x610 net/netlink/af_netlink.c:1320 netlink_sendmsg+0x648/0xbc0 net/netlink/af_netlink.c:1891 sock_sendmsg_nosec net/socket.c:646 [inline] sock_sendmsg+0xb5/0x100 net/socket.c:656 ___sys_sendmsg+0x6c8/0x800 net/socket.c:2062 __sys_sendmsg+0xa3/0x120 net/socket.c:2096 SYSC_sendmsg net/socket.c:2107 [inline] SyS_sendmsg+0x27/0x40 net/socket.c:2103 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb -> #0 (&qdisc_rx_lock){+.-.}: lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:152 spin_lock include/linux/spinlock.h:317 [inline] pie_timer+0x6b/0x630 net/sched/sch_pie.c:431 call_timer_fn+0x14a/0x650 kernel/time/timer.c:1280 expire_timers+0x232/0x4d0 kernel/time/timer.c:1319 __run_timers kernel/time/timer.c:1637 [inline] run_timer_softirq+0x1d5/0x5a0 kernel/time/timer.c:1650 __do_softirq+0x24d/0x9ff kernel/softirq.c:288 invoke_softirq kernel/softirq.c:368 [inline] irq_exit+0x193/0x240 kernel/softirq.c:409 exiting_irq arch/x86/include/asm/apic.h:638 [inline] smp_apic_timer_interrupt+0x141/0x5e0 arch/x86/kernel/apic/apic.c:1106 apic_timer_interrupt+0x93/0xa0 arch/x86/entry/entry_64.S:793 arch_local_irq_restore arch/x86/include/asm/paravirt.h:779 [inline] lock_acquire+0x1ec/0x3f0 kernel/locking/lockdep.c:4001 fs_reclaim_acquire mm/page_alloc.c:3558 [inline] fs_reclaim_acquire+0xf4/0x120 mm/page_alloc.c:3555 slab_pre_alloc_hook mm/slab.h:416 [inline] slab_alloc mm/slab.c:3376 [inline] kmem_cache_alloc_trace+0x29/0x3d0 mm/slab.c:3616 kmalloc include/linux/slab.h:488 [inline] kzalloc include/linux/slab.h:661 [inline] aa_alloc_file_ctx security/apparmor/include/file.h:60 [inline] apparmor_file_alloc_security+0x129/0x800 security/apparmor/lsm.c:431 security_file_alloc+0x66/0xa0 security/security.c:874 get_empty_filp+0x16b/0x3f0 fs/file_table.c:129 path_openat+0x84/0x2970 fs/namei.c:3545 do_filp_open+0x179/0x3c0 fs/namei.c:3603 do_sys_open+0x296/0x410 fs/open.c:1081 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(((&q->adapt_timer))); lock(&qdisc_rx_lock); lock(((&q->adapt_timer))); lock(&qdisc_rx_lock); *** DEADLOCK *** 2 locks held by syz-executor191/8185: #0: (fs_reclaim){+.+.}, at: [] __need_fs_reclaim mm/page_alloc.c:3549 [inline] #0: (fs_reclaim){+.+.}, at: [] fs_reclaim_acquire+0xd4/0x120 mm/page_alloc.c:3557 #1: (((&q->adapt_timer))){+.-.}, at: [] lockdep_copy_map include/linux/lockdep.h:174 [inline] #1: (((&q->adapt_timer))){+.-.}, at: [] call_timer_fn+0xb8/0x650 kernel/time/timer.c:1270 stack backtrace: CPU: 0 PID: 8185 Comm: syz-executor191 Not tainted 4.14.266-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x1b2/0x281 lib/dump_stack.c:58 print_circular_bug.constprop.0.cold+0x2d7/0x41e kernel/locking/lockdep.c:1258 check_prev_add kernel/locking/lockdep.c:1905 [inline] check_prevs_add kernel/locking/lockdep.c:2022 [inline] validate_chain kernel/locking/lockdep.c:2464 [inline] __lock_acquire+0x2e0e/0x3f20 kernel/locking/lockdep.c:3491 lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:152 spin_lock include/linux/spinlock.h:317 [inline] pie_timer+0x6b/0x630 net/sched/sch_pie.c:431 call_timer_fn+0x14a/0x650 kernel/time/timer.c:1280 expire_timers+0x232/0x4d0 kernel/time/timer.c:1319 __run_timers kernel/time/timer.c:1637 [inline] run_timer_softirq+0x1d5/0x5a0 kernel/time/timer.c:1650 __do_softirq+0x24d/0x9ff kernel/softirq.c:288 invoke_softirq kernel/softirq.c:368 [inline] irq_exit+0x193/0x240 kernel/softirq.c:409 exiting_irq arch/x86/include/asm/apic.h:638 [inline] smp_apic_timer_interrupt+0x141/0x5e0 arch/x86/kernel/apic/apic.c:1106 apic_timer_interrupt+0x93/0xa0 arch/x86/entry/entry_64.S:793 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:779 [inline] RIP: 0010:lock_acquire+0x1ec/0x3f0 kernel/locking/lockdep.c:4001 RSP: 0018:ffff88808f96fa68 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff10 RAX: 1ffffffff11e1279 RBX: ffff8880b29b6340 RCX: 0000000000000ec1 RDX: dffffc0000000000 RSI: 0000000000000001 RDI: 0000000000000286 RBP: ffffffff88fd7ae0 R08: ffffffff8b9a90c8 R09: 000000000004008f R10: ffff8880b29b6bc8 R11: ffff8880b29b6340 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000001 fs_reclaim_acquire mm/page_alloc.c:3558 [inline] fs_reclaim_acquire+0xf4/0x120 mm/page_alloc.c:3555 slab_pre_alloc_hook mm/slab.h:416 [inline] slab_alloc mm/slab.c:3376 [inline] kmem_cache_alloc_trace+0x29/0x3d0 mm/slab.c:3616 kmalloc include/linux/slab.h:488 [inline] kzalloc include/linux/slab.h:661 [inline] aa_alloc_file_ctx security/apparmor/include/file.h:60 [inline] apparmor_file_alloc_security+0x129/0x800 security/apparmor/lsm.c:431 security_file_alloc+0x66/0xa0 security/security.c:874 get_empty_filp+0x16b/0x3f0 fs/file_table.c:129 path_openat+0x84/0x2970 fs/namei.c:3545 do_filp_open+0x179/0x3c0 fs/namei.c:3603 do_sys_open+0x296/0x410 fs/open.c:1081 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7fa564afad47 RSP: 002b:00007fff71b3d780 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00007fa564afad47 RDX: 0000000000080001 RSI: 00007fa564b7c04a RDI: 00000000ffffff9c RBP: 00007fa564b7c04a R08: 0000000000000000 R09: 00007fff71b3d770 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000080001 R13: 0000000000000000 R14: 00007fff71b3dd10 R15: 00007fff71b3dd04