Oops: general protection fault, probably for non-canonical address 0xdffffc0000000004: 0000 [#1] SMP KASAN PTI KASAN: null-ptr-deref in range [0x0000000000000020-0x0000000000000027] CPU: 0 UID: 0 PID: 6151 Comm: syz.3.51 Not tainted 6.16.0-rc4-syzkaller-01070-gd23647fd547b #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:qdisc_tree_reduce_backlog+0x223/0x480 net/sched/sch_api.c:806 Code: 89 ef e8 b0 0b ab f8 4d 89 ef 85 db 74 0d e8 34 8b 47 f8 4c 89 f5 e9 88 00 00 00 48 8b 6d 00 48 8d 45 20 48 89 c3 48 c1 eb 03 <42> 80 3c 33 00 48 89 04 24 74 0d 48 8b 3c 24 e8 79 0b ab f8 48 8b RSP: 0018:ffffc9000b92efe8 EFLAGS: 00010202 RAX: 0000000000000020 RBX: 0000000000000004 RCX: 0000000000000002 RDX: ffff88802b549e00 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: ffff88802b549e00 R09: 0000000000000002 R10: 00000000ffffffff R11: 0000000000000002 R12: 00000000000affe0 R13: ffff88807b685800 R14: dffffc0000000000 R15: ffff88807b685800 FS: 00007f832efa76c0(0000) GS:ffff888125c14000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c345967 CR3: 000000002664e000 CR4: 00000000003526f0 Call Trace: fq_change+0x1519/0x1f50 net/sched/sch_fq.c:1147 fq_init+0x699/0x960 net/sched/sch_fq.c:1201 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:6955 netlink_rcv_skb+0x205/0x470 net/netlink/af_netlink.c:2534 netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline] netlink_unicast+0x758/0x8d0 net/netlink/af_netlink.c:1339 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1883 sock_sendmsg_nosec net/socket.c:714 [inline] __sock_sendmsg+0x219/0x270 net/socket.c:729 ____sys_sendmsg+0x505/0x830 net/socket.c:2614 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2668 __sys_sendmsg net/socket.c:2700 [inline] __do_sys_sendmsg net/socket.c:2705 [inline] __se_sys_sendmsg net/socket.c:2703 [inline] __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2703 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: 0033:0x7f832e18e929 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:00007f832efa7038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f832e3b5fa0 RCX: 00007f832e18e929 RDX: 0000000000004000 RSI: 0000200000000280 RDI: 0000000000000005 RBP: 00007f832e210b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f832e3b5fa0 R15: 00007ffe19d804d8 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:qdisc_tree_reduce_backlog+0x223/0x480 net/sched/sch_api.c:806 Code: 89 ef e8 b0 0b ab f8 4d 89 ef 85 db 74 0d e8 34 8b 47 f8 4c 89 f5 e9 88 00 00 00 48 8b 6d 00 48 8d 45 20 48 89 c3 48 c1 eb 03 <42> 80 3c 33 00 48 89 04 24 74 0d 48 8b 3c 24 e8 79 0b ab f8 48 8b RSP: 0018:ffffc9000b92efe8 EFLAGS: 00010202 RAX: 0000000000000020 RBX: 0000000000000004 RCX: 0000000000000002 RDX: ffff88802b549e00 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: ffff88802b549e00 R09: 0000000000000002 R10: 00000000ffffffff R11: 0000000000000002 R12: 00000000000affe0 R13: ffff88807b685800 R14: dffffc0000000000 R15: ffff88807b685800 FS: 00007f832efa76c0(0000) GS:ffff888125c14000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c345967 CR3: 000000002664e000 CR4: 00000000003526f0 ---------------- Code disassembly (best guess): 0: 89 ef mov %ebp,%edi 2: e8 b0 0b ab f8 call 0xf8ab0bb7 7: 4d 89 ef mov %r13,%r15 a: 85 db test %ebx,%ebx c: 74 0d je 0x1b e: e8 34 8b 47 f8 call 0xf8478b47 13: 4c 89 f5 mov %r14,%rbp 16: e9 88 00 00 00 jmp 0xa3 1b: 48 8b 6d 00 mov 0x0(%rbp),%rbp 1f: 48 8d 45 20 lea 0x20(%rbp),%rax 23: 48 89 c3 mov %rax,%rbx 26: 48 c1 eb 03 shr $0x3,%rbx * 2a: 42 80 3c 33 00 cmpb $0x0,(%rbx,%r14,1) <-- trapping instruction 2f: 48 89 04 24 mov %rax,(%rsp) 33: 74 0d je 0x42 35: 48 8b 3c 24 mov (%rsp),%rdi 39: e8 79 0b ab f8 call 0xf8ab0bb7 3e: 48 rex.W 3f: 8b .byte 0x8b