======================================================
WARNING: possible circular locking dependency detected
4.19.141-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor.3/22698 is trying to acquire lock:
0000000054a25b84 (&qdisc_tx_lock){+.-.}, at: spin_lock include/linux/spinlock.h:329 [inline]
0000000054a25b84 (&qdisc_tx_lock){+.-.}, at: red_adaptative_timer+0x92/0x5c0 net/sched/sch_red.c:265

but task is already holding lock:
000000004e542dec ((&q->adapt_timer)){+.-.}, at: lockdep_copy_map include/linux/lockdep.h:168 [inline]
000000004e542dec ((&q->adapt_timer)){+.-.}, at: call_timer_fn+0xc9/0x700 kernel/time/timer.c:1328

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 ((&q->adapt_timer)){+.-.}:
       red_destroy+0x15/0x60 net/sched/sch_red.c:182
       qdisc_destroy+0x180/0x780 net/sched/sch_generic.c:983
       red_change+0x514/0x1080 net/sched/sch_red.c:236
       qdisc_change net/sched/sch_api.c:1239 [inline]
       tc_modify_qdisc+0xf6a/0x1a80 net/sched/sch_api.c:1542
       rtnetlink_rcv_msg+0x453/0xb80 net/core/rtnetlink.c:4778
       netlink_rcv_skb+0x160/0x440 net/netlink/af_netlink.c:2455
       netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
       netlink_unicast+0x4d5/0x690 net/netlink/af_netlink.c:1344
       netlink_sendmsg+0x6bb/0xc40 net/netlink/af_netlink.c:1909
       sock_sendmsg_nosec net/socket.c:622 [inline]
       sock_sendmsg+0xc3/0x120 net/socket.c:632
       ___sys_sendmsg+0x7bb/0x8e0 net/socket.c:2115
       __sys_sendmsg net/socket.c:2153 [inline]
       __do_sys_sendmsg net/socket.c:2162 [inline]
       __se_sys_sendmsg net/socket.c:2160 [inline]
       __x64_sys_sendmsg+0x132/0x220 net/socket.c:2160
       do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
       entry_SYSCALL_64_after_hwframe+0x49/0xbe

-> #0 (&qdisc_tx_lock){+.-.}:
       __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
       _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:144
       spin_lock include/linux/spinlock.h:329 [inline]
       red_adaptative_timer+0x92/0x5c0 net/sched/sch_red.c:265
       call_timer_fn+0x177/0x700 kernel/time/timer.c:1338
       expire_timers+0x243/0x4e0 kernel/time/timer.c:1375
       __run_timers kernel/time/timer.c:1703 [inline]
       run_timer_softirq+0x21c/0x670 kernel/time/timer.c:1716
       __do_softirq+0x26c/0x9a0 kernel/softirq.c:292
       invoke_softirq kernel/softirq.c:372 [inline]
       irq_exit+0x215/0x260 kernel/softirq.c:412
       exiting_irq arch/x86/include/asm/apic.h:544 [inline]
       smp_apic_timer_interrupt+0x136/0x550 arch/x86/kernel/apic/apic.c:1094
       apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:894
       batadv_hardif_get_by_netdev+0x111/0x3e0 net/batman-adv/hard-interface.c:82
       batadv_hard_if_event+0xaf/0x15c0 net/batman-adv/hard-interface.c:1035
       notifier_call_chain+0xc0/0x230 kernel/notifier.c:93
       call_netdevice_notifiers net/core/dev.c:1762 [inline]
       register_netdevice+0xdd2/0x10f0 net/core/dev.c:8747
       veth_newlink+0x4dd/0x930 drivers/net/veth.c:1170
       rtnl_newlink+0x1027/0x15b0 net/core/rtnetlink.c:3141
       rtnetlink_rcv_msg+0x453/0xb80 net/core/rtnetlink.c:4778
       netlink_rcv_skb+0x160/0x440 net/netlink/af_netlink.c:2455
       netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
       netlink_unicast+0x4d5/0x690 net/netlink/af_netlink.c:1344
       netlink_sendmsg+0x6bb/0xc40 net/netlink/af_netlink.c:1909
       sock_sendmsg_nosec net/socket.c:622 [inline]
       sock_sendmsg+0xc3/0x120 net/socket.c:632
       ___sys_sendmsg+0x7bb/0x8e0 net/socket.c:2115
       __sys_sendmsg net/socket.c:2153 [inline]
       __do_sys_sendmsg net/socket.c:2162 [inline]
       __se_sys_sendmsg net/socket.c:2160 [inline]
       __x64_sys_sendmsg+0x132/0x220 net/socket.c:2160
       do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
       entry_SYSCALL_64_after_hwframe+0x49/0xbe

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock((&q->adapt_timer));
                               lock(&qdisc_tx_lock);
                               lock((&q->adapt_timer));
  lock(&qdisc_tx_lock);

 *** DEADLOCK ***

3 locks held by syz-executor.3/22698:
 #0: 000000003b34403b (rtnl_mutex){+.+.}, at: rtnl_lock net/core/rtnetlink.c:77 [inline]
 #0: 000000003b34403b (rtnl_mutex){+.+.}, at: rtnetlink_rcv_msg+0x3fe/0xb80 net/core/rtnetlink.c:4775
 #1: 000000000a407f3a (rcu_read_lock){....}, at: batadv_hardif_get_by_netdev+0x0/0x3e0 include/linux/netdevice.h:3662
 #2: 000000004e542dec ((&q->adapt_timer)){+.-.}, at: lockdep_copy_map include/linux/lockdep.h:168 [inline]
 #2: 000000004e542dec ((&q->adapt_timer)){+.-.}, at: call_timer_fn+0xc9/0x700 kernel/time/timer.c:1328

stack backtrace:
CPU: 1 PID: 22698 Comm: syz-executor.3 Not tainted 4.19.141-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1fc/0x2fe lib/dump_stack.c:118
 print_circular_bug.constprop.0.cold+0x2d7/0x41e kernel/locking/lockdep.c:1221
 check_prev_add kernel/locking/lockdep.c:1865 [inline]
 check_prevs_add kernel/locking/lockdep.c:1978 [inline]
 validate_chain kernel/locking/lockdep.c:2419 [inline]
 __lock_acquire+0x30c9/0x3ff0 kernel/locking/lockdep.c:3415
 lock_acquire+0x170/0x3c0 kernel/locking/lockdep.c:3907
 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
 _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:144
 spin_lock include/linux/spinlock.h:329 [inline]
 red_adaptative_timer+0x92/0x5c0 net/sched/sch_red.c:265
 call_timer_fn+0x177/0x700 kernel/time/timer.c:1338
 expire_timers+0x243/0x4e0 kernel/time/timer.c:1375
 __run_timers kernel/time/timer.c:1703 [inline]
 run_timer_softirq+0x21c/0x670 kernel/time/timer.c:1716
 __do_softirq+0x26c/0x9a0 kernel/softirq.c:292
 invoke_softirq kernel/softirq.c:372 [inline]
 irq_exit+0x215/0x260 kernel/softirq.c:412
 exiting_irq arch/x86/include/asm/apic.h:544 [inline]
 smp_apic_timer_interrupt+0x136/0x550 arch/x86/kernel/apic/apic.c:1094
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:894
 </IRQ>
RIP: 0010:__read_once_size include/linux/compiler.h:193 [inline]
RIP: 0010:batadv_hardif_get_by_netdev+0x111/0x3e0 net/batman-adv/hard-interface.c:82
Code: 00 4c 8b 3d d1 00 30 05 48 8d 44 24 30 48 bb 00 00 00 00 00 fc ff df 48 89 44 24 08 49 81 ff e0 65 50 8c 75 2b e9 d5 01 00 00 <e8> ca 4b 49 fa 4c 89 f8 48 c1 e8 03 80 3c 18 00 0f 85 7b 02 00 00
RSP: 0018:ffff888023fceba8 EFLAGS: 00000202 ORIG_RAX: ffffffffffffff13
RAX: 1ffff110068a1364 RBX: dffffc0000000000 RCX: ffffc9000c0f1000
RDX: 0000000000040000 RSI: ffffffff8720655c RDI: ffff888034509b20
RBP: ffff8880905dce40 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: ffff8880905dce40
R13: 0000000000000000 R14: 0000000000000000 R15: ffff888034509b00
 batadv_hard_if_event+0xaf/0x15c0 net/batman-adv/hard-interface.c:1035
 notifier_call_chain+0xc0/0x230 kernel/notifier.c:93
 call_netdevice_notifiers net/core/dev.c:1762 [inline]
 register_netdevice+0xdd2/0x10f0 net/core/dev.c:8747
 veth_newlink+0x4dd/0x930 drivers/net/veth.c:1170
 rtnl_newlink+0x1027/0x15b0 net/core/rtnetlink.c:3141
 rtnetlink_rcv_msg+0x453/0xb80 net/core/rtnetlink.c:4778
 netlink_rcv_skb+0x160/0x440 net/netlink/af_netlink.c:2455
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x4d5/0x690 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x6bb/0xc40 net/netlink/af_netlink.c:1909
 sock_sendmsg_nosec net/socket.c:622 [inline]
 sock_sendmsg+0xc3/0x120 net/socket.c:632
 ___sys_sendmsg+0x7bb/0x8e0 net/socket.c:2115
 __sys_sendmsg net/socket.c:2153 [inline]
 __do_sys_sendmsg net/socket.c:2162 [inline]
 __se_sys_sendmsg net/socket.c:2160 [inline]
 __x64_sys_sendmsg+0x132/0x220 net/socket.c:2160
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45d579
Code: 5d b4 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 2b b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f88a3733c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 000000000002cd40 RCX: 000000000045d579
RDX: 0000000000000000 RSI: 0000000020000040 RDI: 0000000000000005
RBP: 000000000118cf80 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118cf4c
R13: 00007ffd0aab896f R14: 00007f88a37349c0 R15: 000000000118cf4c
Cannot find add_set index 0 as target
netlink: 'syz-executor.5': attribute type 3 has an invalid length.
audit: type=1800 audit(1598423136.992:62): pid=22710 uid=0 auid=0 ses=4 subj=system_u:system_r:kernel_t:s0 op=collect_data cause=failed comm="syz-executor.0" name="bus" dev="sda1" ino=19193 res=0
Cannot find add_set index 0 as target
audit: type=1800 audit(1598423136.992:63): pid=22723 uid=0 auid=0 ses=4 subj=system_u:system_r:kernel_t:s0 op=collect_data cause=failed comm="syz-executor.0" name="bus" dev="sda1" ino=19193 res=0
Cannot find add_set index 0 as target
netlink: 'syz-executor.5': attribute type 3 has an invalid length.
netlink: 'syz-executor.5': attribute type 3 has an invalid length.
audit: type=1800 audit(1598423137.962:64): pid=22755 uid=0 auid=0 ses=4 subj=system_u:system_r:kernel_t:s0 op=collect_data cause=failed comm="syz-executor.0" name="bus" dev="sda1" ino=19193 res=0
nla_parse: 18 callbacks suppressed
netlink: 24 bytes leftover after parsing attributes in process `syz-executor.3'.
netlink: 'syz-executor.5': attribute type 3 has an invalid length.
netlink: 24 bytes leftover after parsing attributes in process `syz-executor.3'.
netlink: 24 bytes leftover after parsing attributes in process `syz-executor.5'.
audit: type=1800 audit(1598423138.882:65): pid=22851 uid=0 auid=0 ses=4 subj=system_u:system_r:kernel_t:s0 op=collect_data cause=failed comm="syz-executor.0" name="bus" dev="sda1" ino=19193 res=0
netlink: 24 bytes leftover after parsing attributes in process `syz-executor.5'.
set_target_v1_checkentry: 7 callbacks suppressed
Cannot find add_set index 0 as target
netlink: 'syz-executor.5': attribute type 3 has an invalid length.
netlink: 24 bytes leftover after parsing attributes in process `syz-executor.3'.
netlink: 24 bytes leftover after parsing attributes in process `syz-executor.5'.
Cannot find add_set index 0 as target
netlink: 24 bytes leftover after parsing attributes in process `syz-executor.3'.
netlink: 24 bytes leftover after parsing attributes in process `syz-executor.5'.
Cannot find add_set index 0 as target
netlink: 'syz-executor.5': attribute type 3 has an invalid length.
netlink: 24 bytes leftover after parsing attributes in process `syz-executor.5'.
netlink: 24 bytes leftover after parsing attributes in process `syz-executor.3'.
audit: type=1800 audit(1598423139.812:66): pid=22915 uid=0 auid=0 ses=4 subj=system_u:system_r:kernel_t:s0 op=collect_data cause=failed comm="syz-executor.0" name="bus" dev="sda1" ino=19193 res=0
Cannot find add_set index 0 as target
netlink: 'syz-executor.5': attribute type 3 has an invalid length.
Cannot find add_set index 0 as target
Cannot find add_set index 0 as target
Cannot find add_set index 0 as target
Cannot find add_set index 0 as target
netlink: 'syz-executor.5': attribute type 3 has an invalid length.
Cannot find add_set index 0 as target
Cannot find add_set index 0 as target
netlink: 'syz-executor.5': attribute type 3 has an invalid length.
netlink: 'syz-executor.5': attribute type 3 has an invalid length.
netlink: 'syz-executor.5': attribute type 3 has an invalid length.
validate_nla: 2 callbacks suppressed
netlink: 'syz-executor.5': attribute type 3 has an invalid length.
nla_parse: 31 callbacks suppressed
netlink: 24 bytes leftover after parsing attributes in process `syz-executor.5'.
netlink: 24 bytes leftover after parsing attributes in process `syz-executor.3'.
netlink: 24 bytes leftover after parsing attributes in process `syz-executor.5'.
netlink: 24 bytes leftover after parsing attributes in process `syz-executor.5'.
netlink: 24 bytes leftover after parsing attributes in process `syz-executor.5'.
netlink: 24 bytes leftover after parsing attributes in process `syz-executor.3'.
netlink: 24 bytes leftover after parsing attributes in process `syz-executor.3'.
netlink: 'syz-executor.5': attribute type 3 has an invalid length.
netlink: 24 bytes leftover after parsing attributes in process `syz-executor.5'.
netlink: 24 bytes leftover after parsing attributes in process `syz-executor.5'.
set_target_v1_checkentry: 22 callbacks suppressed
Cannot find add_set index 0 as target
netlink: 24 bytes leftover after parsing attributes in process `syz-executor.3'.
Cannot find add_set index 0 as target
netlink: 'syz-executor.5': attribute type 3 has an invalid length.
Cannot find add_set index 0 as target
Cannot find add_set index 0 as target
Cannot find add_set index 0 as target
Cannot find add_set index 0 as target
Cannot find add_set index 0 as target
Cannot find add_set index 0 as target
netlink: 'syz-executor.5': attribute type 3 has an invalid length.
Cannot find add_set index 0 as target
netlink: 'syz-executor.5': attribute type 3 has an invalid length.
Cannot find add_set index 0 as target
netlink: 'syz-executor.5': attribute type 3 has an invalid length.