general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] CPU: 0 PID: 22731 Comm: syz.6.5502 Not tainted 6.1.147-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 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+0xd2d/0x1590 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 38 c3 82 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 15 c3 82 f9 48 ba 00 00 00 00 00 fc RSP: 0018:ffffc90003cde9e0 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 1ffff9200079bdb4 RCX: 1ffff1100e615e5a RDX: dffffc0000000000 RSI: 0000000000002378 RDI: 0000000000002379 RBP: ffffc90003cdeb30 R08: dffffc0000000000 R09: fffffbfff215ba80 R10: fffffbfff215ba80 R11: 1ffffffff215ba7f R12: 0000000000000000 R13: ffff888030bb1800 R14: 0000000000000000 R15: 0000000000000000 FS: 00007f2de9d736c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f39271a70c2 CR3: 000000001ff42000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: qdisc_enqueue include/net/sch_generic.h:816 [inline] sfb_enqueue+0x9e0/0x17d0 net/sched/sch_sfb.c:405 dev_qdisc_enqueue+0x4c/0x2b0 net/core/dev.c:3863 __dev_xmit_skb net/core/dev.c:3952 [inline] __dev_queue_xmit+0xf8e/0x3760 net/core/dev.c:4300 dev_queue_xmit include/linux/netdevice.h:3051 [inline] tipc_l2_send_msg+0x30f/0x3d0 net/tipc/bearer.c:518 tipc_bearer_xmit_skb+0x2a9/0x3f0 net/tipc/bearer.c:577 tipc_enable_bearer net/tipc/bearer.c:368 [inline] __tipc_nl_bearer_enable+0x1025/0x13a0 net/tipc/bearer.c:1049 __tipc_nl_compat_doit net/tipc/netlink_compat.c:375 [inline] tipc_nl_compat_doit+0x3cb/0x5f0 net/tipc/netlink_compat.c:397 tipc_nl_compat_handle net/tipc/netlink_compat.c:-1 [inline] tipc_nl_compat_recv+0x4fb/0xaa0 net/tipc/netlink_compat.c:1325 genl_family_rcv_msg_doit+0x22e/0x320 net/netlink/genetlink.c:756 genl_family_rcv_msg net/netlink/genetlink.c:833 [inline] genl_rcv_msg+0x5f2/0x780 net/netlink/genetlink.c:850 netlink_rcv_skb+0x1de/0x420 net/netlink/af_netlink.c:2511 genl_rcv+0x24/0x40 net/netlink/genetlink.c:861 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x74d/0x8d0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x89e/0xbc0 net/netlink/af_netlink.c:1872 sock_sendmsg_nosec net/socket.c:718 [inline] __sock_sendmsg net/socket.c:730 [inline] ____sys_sendmsg+0x59b/0x970 net/socket.c:2519 ___sys_sendmsg+0x21c/0x290 net/socket.c:2573 __sys_sendmsg net/socket.c:2602 [inline] __do_sys_sendmsg net/socket.c:2611 [inline] __se_sys_sendmsg+0x19e/0x270 net/socket.c:2609 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f2de8f8eb69 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f2de9d73038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f2de91b5fa0 RCX: 00007f2de8f8eb69 RDX: 0000000000000000 RSI: 00002000000002c0 RDI: 0000000000000004 RBP: 00007f2de9011df1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f2de91b5fa0 R15: 00007fff05181638 Modules linked in: ---[ end trace 0000000000000000 ]--- 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+0xd2d/0x1590 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 38 c3 82 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 15 c3 82 f9 48 ba 00 00 00 00 00 fc RSP: 0018:ffffc90003cde9e0 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 1ffff9200079bdb4 RCX: 1ffff1100e615e5a RDX: dffffc0000000000 RSI: 0000000000002378 RDI: 0000000000002379 RBP: ffffc90003cdeb30 R08: dffffc0000000000 R09: fffffbfff215ba80 R10: fffffbfff215ba80 R11: 1ffffffff215ba7f R12: 0000000000000000 R13: ffff888030bb1800 R14: 0000000000000000 R15: 0000000000000000 FS: 00007f2de9d736c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f39271a70c2 CR3: 000000001ff42000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- 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 38 c3 82 f9 call 0xf982c34d 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 15 c3 82 f9 call 0xf982c34d 38: 48 rex.W 39: ba 00 00 00 00 mov $0x0,%edx 3e: 00 fc add %bh,%ah