general protection fault, probably for non-canonical address 0xdffffc0000000004: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000020-0x0000000000000027] CPU: 0 PID: 14711 Comm: syz.0.6035 Tainted: G W 5.15.187-syzkaller-00603-geabc268e4fb2 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:qdisc_tree_reduce_backlog+0x181/0x340 net/sched/sch_api.c:795 Code: e8 f4 89 d7 fd 4d 89 ef 83 7d d0 00 74 0a e8 d6 12 99 fd e9 80 00 00 00 4d 8b 36 49 8d 46 20 48 89 c1 48 c1 e9 03 48 89 4d b8 <80> 3c 19 00 48 89 45 d0 74 0d 48 8b 7d d0 e8 bc 89 d7 fd 48 8b 45 RSP: 0018:ffffc90000d06f08 EFLAGS: 00010202 RAX: 0000000000000020 RBX: dffffc0000000000 RCX: 0000000000000004 RDX: 0000000000000002 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90000d06f50 R08: ffff888132402780 R09: 0000000000000002 R10: 00000000ffffffff R11: 0000000000000002 R12: 00000000000affe0 R13: ffff888131a88800 R14: 0000000000000000 R15: ffff888131a88800 FS: 00007f0b9af566c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000032 CR3: 000000010a86b000 CR4: 00000000003526b0 DR0: 0000000000000000 DR1: 000000000000580b DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: fq_change+0xc25/0x11f0 net/sched/sch_fq.c:915 fq_init+0x3e3/0x5d0 net/sched/sch_fq.c:963 qdisc_create+0x7ed/0x11a0 net/sched/sch_api.c:1261 tc_modify_qdisc+0x896/0x1480 net/sched/sch_api.c:-1 rtnetlink_rcv_msg+0x9e4/0xb90 net/core/rtnetlink.c:5650 netlink_rcv_skb+0x1e0/0x430 net/netlink/af_netlink.c:2493 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:5668 netlink_unicast_kernel net/netlink/af_netlink.c:1315 [inline] netlink_unicast+0x87c/0xa40 net/netlink/af_netlink.c:1341 netlink_sendmsg+0x86a/0xb70 net/netlink/af_netlink.c:1909 sock_sendmsg_nosec net/socket.c:704 [inline] __sock_sendmsg net/socket.c:716 [inline] ____sys_sendmsg+0x5a2/0x8c0 net/socket.c:2436 ___sys_sendmsg+0x1f0/0x260 net/socket.c:2490 __sys_sendmsg net/socket.c:2519 [inline] __do_sys_sendmsg net/socket.c:2528 [inline] __se_sys_sendmsg net/socket.c:2526 [inline] __x64_sys_sendmsg+0x1e2/0x2a0 net/socket.c:2526 x64_sys_call+0x4b/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:47 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: 0033:0x7f0b9c8ed929 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:00007f0b9af56038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f0b9cb14fa0 RCX: 00007f0b9c8ed929 RDX: 0000000000004000 RSI: 0000200000000280 RDI: 0000000000000003 RBP: 00007f0b9c96fb39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f0b9cb14fa0 R15: 00007fff4d14f318 Modules linked in: ---[ end trace 54aed8c19d1ecb36 ]--- RIP: 0010:qdisc_tree_reduce_backlog+0x181/0x340 net/sched/sch_api.c:795 Code: e8 f4 89 d7 fd 4d 89 ef 83 7d d0 00 74 0a e8 d6 12 99 fd e9 80 00 00 00 4d 8b 36 49 8d 46 20 48 89 c1 48 c1 e9 03 48 89 4d b8 <80> 3c 19 00 48 89 45 d0 74 0d 48 8b 7d d0 e8 bc 89 d7 fd 48 8b 45 RSP: 0018:ffffc90000d06f08 EFLAGS: 00010202 RAX: 0000000000000020 RBX: dffffc0000000000 RCX: 0000000000000004 RDX: 0000000000000002 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90000d06f50 R08: ffff888132402780 R09: 0000000000000002 R10: 00000000ffffffff R11: 0000000000000002 R12: 00000000000affe0 R13: ffff888131a88800 R14: 0000000000000000 R15: ffff888131a88800 FS: 00007f0b9af566c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000032 CR3: 000000010a86b000 CR4: 00000000003506b0 DR0: 0000000000000000 DR1: 000000000000580b DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: e8 f4 89 d7 fd call 0xfdd789f9 5: 4d 89 ef mov %r13,%r15 8: 83 7d d0 00 cmpl $0x0,-0x30(%rbp) c: 74 0a je 0x18 e: e8 d6 12 99 fd call 0xfd9912e9 13: e9 80 00 00 00 jmp 0x98 18: 4d 8b 36 mov (%r14),%r14 1b: 49 8d 46 20 lea 0x20(%r14),%rax 1f: 48 89 c1 mov %rax,%rcx 22: 48 c1 e9 03 shr $0x3,%rcx 26: 48 89 4d b8 mov %rcx,-0x48(%rbp) * 2a: 80 3c 19 00 cmpb $0x0,(%rcx,%rbx,1) <-- trapping instruction 2e: 48 89 45 d0 mov %rax,-0x30(%rbp) 32: 74 0d je 0x41 34: 48 8b 7d d0 mov -0x30(%rbp),%rdi 38: e8 bc 89 d7 fd call 0xfdd789f9 3d: 48 rex.W 3e: 8b .byte 0x8b 3f: 45 rex.RB