============================================
WARNING: possible recursive locking detected
syzkaller #0 Not tainted
--------------------------------------------
syz.1.8015/6810 is trying to acquire lock:
ffff88807c3a4558 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: spin_lock include/linux/spinlock.h:342 [inline]
ffff88807c3a4558 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: __netif_tx_lock include/linux/netdevice.h:4780 [inline]
ffff88807c3a4558 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: sch_direct_xmit+0x15f/0x4c0 net/sched/sch_generic.c:370
but task is already holding lock:
ffff88808b671158 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: spin_lock include/linux/spinlock.h:342 [inline]
ffff88808b671158 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: __netif_tx_lock include/linux/netdevice.h:4780 [inline]
ffff88808b671158 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: sch_direct_xmit+0x15f/0x4c0 net/sched/sch_generic.c:370
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(&qdisc_xmit_lock_key#4);
lock(&qdisc_xmit_lock_key#4);
*** DEADLOCK ***
May be due to missing lock nesting notation
14 locks held by syz.1.8015/6810:
#0: ffff888032aed6e8 (nlk_cb_mutex-SOCK_DIAG){+.+.}-{4:4}, at: __netlink_dump_start+0xfe/0x7e0 net/netlink/af_netlink.c:2404
#1: ffff8880a317cc60 (sk_lock-AF_INET6){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1713 [inline]
#1: ffff8880a317cc60 (sk_lock-AF_INET6){+.+.}-{0:0}, at: sctp_sock_dump+0xb8/0x870 net/sctp/diag.c:307
#2: ffffc90000007cc0 ((&ndev->rs_timer)){+.-.}-{0:0}, at: call_timer_fn+0xd4/0x5e0 kernel/time/timer.c:1745
#3: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#3: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#3: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: ndisc_send_skb+0x215/0x1670 net/ipv6/ndisc.c:482
#4: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#4: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#4: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: ip6_output+0x126/0x550 net/ipv6/ip6_output.c:234
#5: ffffffff8e95cdc0 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline]
#5: ffffffff8e95cdc0 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:891 [inline]
#5: ffffffff8e95cdc0 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x2b6/0x3950 net/core/dev.c:4791
#6: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#6: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#6: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: bond_start_xmit+0xb4/0x1900 drivers/net/bonding/bond_main.c:5591
#7: ffffffff8e95cdc0 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline]
#7: ffffffff8e95cdc0 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:891 [inline]
#7: ffffffff8e95cdc0 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x2b6/0x3950 net/core/dev.c:4791
#8: ffff88805e3aa228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#5){+...}-{3:3}, at: spin_trylock include/linux/spinlock.h:354 [inline]
#8: ffff88805e3aa228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#5){+...}-{3:3}, at: qdisc_run_begin include/net/sch_generic.h:205 [inline]
#8: ffff88805e3aa228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#5){+...}-{3:3}, at: __dev_xmit_skb net/core/dev.c:4196 [inline]
#8: ffff88805e3aa228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#5){+...}-{3:3}, at: __dev_queue_xmit+0x11a6/0x3950 net/core/dev.c:4831
#9: ffff88808b671158 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: spin_lock include/linux/spinlock.h:342 [inline]
#9: ffff88808b671158 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: __netif_tx_lock include/linux/netdevice.h:4780 [inline]
#9: ffff88808b671158 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: sch_direct_xmit+0x15f/0x4c0 net/sched/sch_generic.c:370
#10: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#10: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#10: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: ip_output+0x5b/0x450 net/ipv4/ip_output.c:433
#11: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#11: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#11: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: ip_finish_output2+0x3c2/0x1070 net/ipv4/ip_output.c:230
#12: ffffffff8e95cdc0 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline]
#12: ffffffff8e95cdc0 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:891 [inline]
#12: ffffffff8e95cdc0 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x2b6/0x3950 net/core/dev.c:4791
#13: ffff8880b0596228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#5){+...}-{3:3}, at: spin_trylock include/linux/spinlock.h:354 [inline]
#13: ffff8880b0596228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#5){+...}-{3:3}, at: qdisc_run_begin include/net/sch_generic.h:205 [inline]
#13: ffff8880b0596228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#5){+...}-{3:3}, at: __dev_xmit_skb net/core/dev.c:4196 [inline]
#13: ffff8880b0596228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#5){+...}-{3:3}, at: __dev_queue_xmit+0x11a6/0x3950 net/core/dev.c:4831
stack backtrace:
CPU: 0 UID: 0 PID: 6810 Comm: syz.1.8015 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
print_deadlock_bug+0x279/0x290 kernel/locking/lockdep.c:3041
check_deadlock kernel/locking/lockdep.c:3093 [inline]
validate_chain kernel/locking/lockdep.c:3895 [inline]
__lock_acquire+0x253f/0x2cf0 kernel/locking/lockdep.c:5237
lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868
__raw_spin_lock include/linux/spinlock_api_smp.h:158 [inline]
_raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:158
spin_lock include/linux/spinlock.h:342 [inline]
__netif_tx_lock include/linux/netdevice.h:4780 [inline]
sch_direct_xmit+0x15f/0x4c0 net/sched/sch_generic.c:370
__dev_xmit_skb net/core/dev.c:4209 [inline]
__dev_queue_xmit+0x180f/0x3950 net/core/dev.c:4831
neigh_output include/net/neighbour.h:556 [inline]
ip_finish_output2+0xca9/0x1070 net/ipv4/ip_output.c:237
NF_HOOK_COND include/linux/netfilter.h:307 [inline]
ip_output+0x29f/0x450 net/ipv4/ip_output.c:438
iptunnel_xmit+0x621/0xd10 net/ipv4/ip_tunnel_core.c:97
ip_tunnel_xmit+0x193a/0x1f20 net/ipv4/ip_tunnel.c:845
__gre_xmit+0x19e/0x240 net/ipv4/ip_gre.c:491
erspan_xmit+0xa41/0x14d0 net/ipv4/ip_gre.c:750
__netdev_start_xmit include/linux/netdevice.h:5367 [inline]
netdev_start_xmit include/linux/netdevice.h:5376 [inline]
xmit_one net/core/dev.c:3888 [inline]
dev_hard_start_xmit+0x2cd/0x830 net/core/dev.c:3904
sch_direct_xmit+0x251/0x4c0 net/sched/sch_generic.c:372
__dev_xmit_skb net/core/dev.c:4209 [inline]
__dev_queue_xmit+0x180f/0x3950 net/core/dev.c:4831
__bond_start_xmit drivers/net/bonding/bond_main.c:5571 [inline]
bond_start_xmit+0x766/0x1900 drivers/net/bonding/bond_main.c:5593
__netdev_start_xmit include/linux/netdevice.h:5367 [inline]
netdev_start_xmit include/linux/netdevice.h:5376 [inline]
xmit_one net/core/dev.c:3888 [inline]
dev_hard_start_xmit+0x2cd/0x830 net/core/dev.c:3904
__dev_queue_xmit+0x14d9/0x3950 net/core/dev.c:4870
NF_HOOK_COND include/linux/netfilter.h:307 [inline]
ip6_output+0x340/0x550 net/ipv6/ip6_output.c:246
dst_output include/net/dst.h:470 [inline]
NF_HOOK include/linux/netfilter.h:318 [inline]
ndisc_send_skb+0xd0b/0x1670 net/ipv6/ndisc.c:512
addrconf_rs_timer+0x395/0x6d0 net/ipv6/addrconf.c:4049
call_timer_fn+0x192/0x5e0 kernel/time/timer.c:1748
expire_timers kernel/time/timer.c:1799 [inline]
__run_timers kernel/time/timer.c:2374 [inline]
__run_timer_base+0x652/0x8b0 kernel/time/timer.c:2386
run_timer_base kernel/time/timer.c:2395 [inline]
run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2405
handle_softirqs+0x22a/0x840 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0xca/0x220 kernel/softirq.c:735
irq_exit_rcu+0x9/0x30 kernel/softirq.c:752
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1061
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:kasan_check_range+0x1c8/0x2c0 mm/kasan/generic.c:200
Code: 49 01 dc 4d 01 f3 49 8d 5c 24 07 4d 85 e4 49 0f 49 dc 48 83 e3 f8 49 29 dc 74 0e 41 80 3b 00 75 7c 49 ff c3 49 ff cc 75 f2 5b <41> 5c 41 5d 41 5e 41 5f 5d e9 8a 36 7a 09 cc 45 84 ff 0f 85 a1 00
RSP: 0018:ffffc9000e3dec48 EFLAGS: 00000256
RAX: ffff888031184001 RBX: 0000000000000001 RCX: ffffffff84ed9d90
RDX: 0000000000000001 RSI: 0000000000000001 RDI: ffff88803118405c
RBP: 0000000000000008 R08: ffff88803118405c R09: 1ffff1100623080b
R10: dffffc0000000000 R11: ffffed100623080c R12: 0000000000000001
R13: 0000000000000008 R14: ffffed100623080c R15: 1ffff1100623080b
__asan_memcpy+0x40/0x70 mm/kasan/shadow.c:106
nla_put+0xd0/0x150 lib/nlattr.c:1099
nla_put_u8 include/net/netlink.h:1394 [inline]
inet_diag_msg_attrs_fill+0x103/0xbf0 net/ipv4/inet_diag.c:105
inet_sctp_diag_fill+0x803/0x1b50 net/sctp/diag.c:160
sctp_sock_dump+0x461/0x870 net/sctp/diag.c:322
sctp_transport_traverse_process+0x377/0x490 net/sctp/socket.c:5440
sctp_diag_dump+0x308/0x3f0 net/sctp/diag.c:511
__inet_diag_dump net/ipv4/inet_diag.c:823 [inline]
inet_diag_dump+0x16d/0x2f0 net/ipv4/inet_diag.c:842
netlink_dump+0x702/0xe10 net/netlink/af_netlink.c:2325
__netlink_dump_start+0x5cb/0x7e0 net/netlink/af_netlink.c:2440
netlink_dump_start include/linux/netlink.h:341 [inline]
inet_diag_handler_cmd+0x1e0/0x2c0 net/ipv4/inet_diag.c:983
sock_diag_rcv_msg+0x4cc/0x600 net/core/sock_diag.c:-1
netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2550
netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
netlink_unicast+0x75c/0x8e0 net/netlink/af_netlink.c:1344
netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1894
sock_sendmsg_nosec net/socket.c:787 [inline]
__sock_sendmsg net/socket.c:802 [inline]
sock_write_iter+0x49b/0x4f0 net/socket.c:1254
do_iter_readv_writev+0x619/0x8c0 fs/read_write.c:-1
vfs_writev+0x33c/0x990 fs/read_write.c:1059
do_writev+0x154/0x2e0 fs/read_write.c:1105
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe3f199cdd9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fe3f277a028 EFLAGS: 00000246 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX: 00007fe3f1c15fa0 RCX: 00007fe3f199cdd9
RDX: 0000000000000001 RSI: 0000200000000000 RDI: 0000000000000007
RBP: 00007fe3f1a32d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe3f1c16038 R14: 00007fe3f1c15fa0 R15: 00007fff2ca91e18
ip6_tunnel: ip6tnl1 xmit: Local address not yet configured!
ip6_tunnel: ip6gre1 xmit: Local address not yet configured!
----------------
Code disassembly (best guess):
0: 49 01 dc add %rbx,%r12
3: 4d 01 f3 add %r14,%r11
6: 49 8d 5c 24 07 lea 0x7(%r12),%rbx
b: 4d 85 e4 test %r12,%r12
e: 49 0f 49 dc cmovns %r12,%rbx
12: 48 83 e3 f8 and $0xfffffffffffffff8,%rbx
16: 49 29 dc sub %rbx,%r12
19: 74 0e je 0x29
1b: 41 80 3b 00 cmpb $0x0,(%r11)
1f: 75 7c jne 0x9d
21: 49 ff c3 inc %r11
24: 49 ff cc dec %r12
27: 75 f2 jne 0x1b
29: 5b pop %rbx
* 2a: 41 5c pop %r12 <-- trapping instruction
2c: 41 5d pop %r13
2e: 41 5e pop %r14
30: 41 5f pop %r15
32: 5d pop %rbp
33: e9 8a 36 7a 09 jmp 0x97a36c2
38: cc int3
39: 45 84 ff test %r15b,%r15b
3c: 0f .byte 0xf
3d: 85 .byte 0x85
3e: a1 .byte 0xa1