general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 1 PID: 6929 Comm: syz.4.536 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:dequeue_head net/sched/sch_fq_codel.c:120 [inline]
RIP: 0010:fq_codel_drop net/sched/sch_fq_codel.c:168 [inline]
RIP: 0010:fq_codel_enqueue+0xd71/0x1600 net/sched/sch_fq_codel.c:230
Code: 24 08 48 8b 44 24 20 80 3c 10 00 74 12 4c 89 ef e8 24 73 ab f9 48 ba 00 00 00 00 00 fc ff df 4d 8b 65 00 4c 89 e0 48 c1 e8 03 <80> 3c 10 00 74 12 4c 89 e7 e8 01 73 ab f9 48 ba 00 00 00 00 00 fc
RSP: 0018:ffffc90000dd0540 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 1ffff920001ba108 RCX: 1ffff1100ee9975a
RDX: dffffc0000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90000dd06a0 R08: ffffffff901d818f R09: 1ffffffff203b031
R10: dffffc0000000000 R11: fffffbfff203b032 R12: 0000000000000000
R13: ffff888034f80000 R14: 0000000000000000 R15: 0000000000000000
FS: 00007f482b0e26c0(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f5a9132dc38 CR3: 0000000088090000 CR4: 00000000003506e0
Call Trace:
qdisc_enqueue include/net/sch_generic.h:842 [inline]
tbf_enqueue+0x224/0x6e0 net/sched/sch_tbf.c:243
dev_qdisc_enqueue+0x48/0x210 net/core/dev.c:3865
__dev_xmit_skb net/core/dev.c:3949 [inline]
__dev_queue_xmit+0xc25/0x2f80 net/core/dev.c:4266
tipc_l2_send_msg+0x30a/0x3c0 net/tipc/bearer.c:518
tipc_bearer_xmit_skb+0x292/0x3c0 net/tipc/bearer.c:577
tipc_disc_timeout+0x57d/0x6d0 net/tipc/discover.c:338
call_timer_fn+0x17b/0x540 kernel/time/timer.c:1648
expire_timers kernel/time/timer.c:1699 [inline]
__run_timers+0x53e/0x800 kernel/time/timer.c:1970
run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1983
handle_softirqs+0x339/0x830 kernel/softirq.c:576
__do_softirq kernel/softirq.c:610 [inline]
invoke_softirq kernel/softirq.c:450 [inline]
__irq_exit_rcu+0x13b/0x230 kernel/softirq.c:659
irq_exit_rcu+0x5/0x20 kernel/softirq.c:671
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:finish_lock_switch+0x134/0x280 kernel/sched/core.c:4804
Code: be ff ff ff ff e8 4c ee 68 08 85 c0 74 4a 4d 85 ff 75 66 0f 1f 44 00 00 48 89 df e8 f6 59 72 08 e8 f1 e6 2a 00 fb 48 83 c4 08 <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 48 89 df e8 c9 09 fe ff 43 80 3c
RSP: 0018:ffffc900036df2c8 EFLAGS: 00000282
RAX: d1bbf48a1528e100 RBX: ffff8880b913a340 RCX: d1bbf48a1528e100
RDX: dffffc0000000000 RSI: ffffffff8a2b3180 RDI: ffffffff8a7a09c0
RBP: 1ffff11017227613 R08: ffff8880b913a343 R09: 1ffff11017227468
R10: dffffc0000000000 R11: ffffed1017227469 R12: 1ffff110172275c1
R13: dffffc0000000000 R14: ffff8880b913ae08 R15: 0000000000000000
finish_task_switch+0x12f/0x640 kernel/sched/core.c:4921
context_switch kernel/sched/core.c:5052 [inline]
__schedule+0x11f7/0x43c0 kernel/sched/core.c:6395
schedule+0x11b/0x1e0 kernel/sched/core.c:6478
schedule_timeout+0xbd/0x2d0 kernel/time/timer.c:2093
unix_wait_for_peer+0x1f2/0x2e0 net/unix/af_unix.c:1315
unix_dgram_sendmsg+0x1083/0x18a0 net/unix/af_unix.c:1910
sock_sendmsg_nosec net/socket.c:706 [inline]
__sock_sendmsg net/socket.c:718 [inline]
____sys_sendmsg+0x5b7/0x8f0 net/socket.c:2445
___sys_sendmsg+0x236/0x2e0 net/socket.c:2499
__sys_sendmmsg+0x2ba/0x500 net/socket.c:2585
__do_sys_sendmmsg net/socket.c:2614 [inline]
__se_sys_sendmmsg net/socket.c:2611 [inline]
__x64_sys_sendmmsg+0x9c/0xb0 net/socket.c:2611
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f482ce88e59
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:00007f482b0e2028 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00007f482d101fa0 RCX: 00007f482ce88e59
RDX: 0400000000000041 RSI: 0000200000000000 RDI: 0000000000000005
RBP: 00007f482cf1ed6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f482d102038 R14: 00007f482d101fa0 R15: 00007ffc054f1c78
Modules linked in:
---[ end trace 8847edbb9a635b03 ]---
RIP: 0010:dequeue_head net/sched/sch_fq_codel.c:120 [inline]
RIP: 0010:fq_codel_drop net/sched/sch_fq_codel.c:168 [inline]
RIP: 0010:fq_codel_enqueue+0xd71/0x1600 net/sched/sch_fq_codel.c:230
Code: 24 08 48 8b 44 24 20 80 3c 10 00 74 12 4c 89 ef e8 24 73 ab f9 48 ba 00 00 00 00 00 fc ff df 4d 8b 65 00 4c 89 e0 48 c1 e8 03 <80> 3c 10 00 74 12 4c 89 e7 e8 01 73 ab f9 48 ba 00 00 00 00 00 fc
RSP: 0018:ffffc90000dd0540 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 1ffff920001ba108 RCX: 1ffff1100ee9975a
RDX: dffffc0000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90000dd06a0 R08: ffffffff901d818f R09: 1ffffffff203b031
R10: dffffc0000000000 R11: fffffbfff203b032 R12: 0000000000000000
R13: ffff888034f80000 R14: 0000000000000000 R15: 0000000000000000
FS: 00007f482b0e26c0(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f5a9132dc38 CR3: 0000000088090000 CR4: 00000000003506e0
----------------
Code disassembly (best guess):
0: 24 08 and $0x8,%al
2: 48 8b 44 24 20 mov 0x20(%rsp),%rax
7: 80 3c 10 00 cmpb $0x0,(%rax,%rdx,1)
b: 74 12 je 0x1f
d: 4c 89 ef mov %r13,%rdi
10: e8 24 73 ab f9 call 0xf9ab7339
15: 48 ba 00 00 00 00 00 movabs $0xdffffc0000000000,%rdx
1c: fc ff df
1f: 4d 8b 65 00 mov 0x0(%r13),%r12
23: 4c 89 e0 mov %r12,%rax
26: 48 c1 e8 03 shr $0x3,%rax
* 2a: 80 3c 10 00 cmpb $0x0,(%rax,%rdx,1) <-- trapping instruction
2e: 74 12 je 0x42
30: 4c 89 e7 mov %r12,%rdi
33: e8 01 73 ab f9 call 0xf9ab7339
38: 48 rex.W
39: ba 00 00 00 00 mov $0x0,%edx
3e: 00 fc add %bh,%ah