Oops: general protection fault, probably for non-canonical address 0xdffffc000000000b: 0000 [#1] SMP KASAN PTI KASAN: null-ptr-deref in range [0x0000000000000058-0x000000000000005f] CPU: 0 UID: 0 PID: 7916 Comm: syz.3.625 Not tainted 6.16.0-rc4-syzkaller-00324-g1f988d0788f5 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:list_empty include/linux/list.h:373 [inline] RIP: 0010:qfq_qlen_notify+0x29/0x70 net/sched/sch_qfq.c:1422 Code: 90 f3 0f 1e fa 41 57 41 56 53 48 89 f3 49 89 fe e8 ac 49 3e f8 4c 8d 7b 58 4c 89 f8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 4c 89 ff e8 99 a1 9f f8 49 8b 07 4c 39 f8 74 1c RSP: 0018:ffffc900054ff160 EFLAGS: 00010202 RAX: 000000000000000b RBX: 0000000000000000 RCX: dffffc0000000000 RDX: ffffc9000d2ac000 RSI: 0000000000000360 RDI: 0000000000000361 RBP: dffffc0000000000 R08: ffff888035cd1e00 R09: 0000000000000002 R10: 00000000ffffffff R11: ffffffff898213c0 R12: 0000000000000000 R13: ffff888056250000 R14: ffff888056250000 R15: 0000000000000058 FS: 00007f750ae086c0(0000) GS:ffff888125c50000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c31a0de CR3: 0000000071962000 CR4: 00000000003526f0 Call Trace: qdisc_tree_reduce_backlog+0x29c/0x480 net/sched/sch_api.c:811 sfq_change net/sched/sch_sfq.c:740 [inline] sfq_init+0x1a0f/0x2530 net/sched/sch_sfq.c:804 qdisc_create+0x7ac/0xea0 net/sched/sch_api.c:1324 __tc_modify_qdisc net/sched/sch_api.c:1749 [inline] tc_modify_qdisc+0x1426/0x2010 net/sched/sch_api.c:1813 rtnetlink_rcv_msg+0x779/0xb70 net/core/rtnetlink.c:6953 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2534 netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline] netlink_unicast+0x75b/0x8d0 net/netlink/af_netlink.c:1339 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1883 sock_sendmsg_nosec net/socket.c:712 [inline] __sock_sendmsg+0x21c/0x270 net/socket.c:727 ____sys_sendmsg+0x505/0x830 net/socket.c:2566 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2620 __sys_sendmsg net/socket.c:2652 [inline] __do_sys_sendmsg net/socket.c:2657 [inline] __se_sys_sendmsg net/socket.c:2655 [inline] __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2655 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f7509f8e929 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:00007f750ae08038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f750a1b6080 RCX: 00007f7509f8e929 RDX: 0000000000004000 RSI: 0000200000000040 RDI: 000000000000000d RBP: 00007f750a010b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f750a1b6080 R15: 00007ffd0a0ac3c8 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:list_empty include/linux/list.h:373 [inline] RIP: 0010:qfq_qlen_notify+0x29/0x70 net/sched/sch_qfq.c:1422 Code: 90 f3 0f 1e fa 41 57 41 56 53 48 89 f3 49 89 fe e8 ac 49 3e f8 4c 8d 7b 58 4c 89 f8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 4c 89 ff e8 99 a1 9f f8 49 8b 07 4c 39 f8 74 1c RSP: 0018:ffffc900054ff160 EFLAGS: 00010202 RAX: 000000000000000b RBX: 0000000000000000 RCX: dffffc0000000000 RDX: ffffc9000d2ac000 RSI: 0000000000000360 RDI: 0000000000000361 RBP: dffffc0000000000 R08: ffff888035cd1e00 R09: 0000000000000002 R10: 00000000ffffffff R11: ffffffff898213c0 R12: 0000000000000000 R13: ffff888056250000 R14: ffff888056250000 R15: 0000000000000058 FS: 00007f750ae086c0(0000) GS:ffff888125c50000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c31a0de CR3: 0000000071962000 CR4: 00000000003526f0 ---------------- Code disassembly (best guess): 0: 90 nop 1: f3 0f 1e fa endbr64 5: 41 57 push %r15 7: 41 56 push %r14 9: 53 push %rbx a: 48 89 f3 mov %rsi,%rbx d: 49 89 fe mov %rdi,%r14 10: e8 ac 49 3e f8 call 0xf83e49c1 15: 4c 8d 7b 58 lea 0x58(%rbx),%r15 19: 4c 89 f8 mov %r15,%rax 1c: 48 c1 e8 03 shr $0x3,%rax 20: 48 b9 00 00 00 00 00 movabs $0xdffffc0000000000,%rcx 27: fc ff df * 2a: 80 3c 08 00 cmpb $0x0,(%rax,%rcx,1) <-- trapping instruction 2e: 74 08 je 0x38 30: 4c 89 ff mov %r15,%rdi 33: e8 99 a1 9f f8 call 0xf89fa1d1 38: 49 8b 07 mov (%r15),%rax 3b: 4c 39 f8 cmp %r15,%rax 3e: 74 1c je 0x5c