general protection fault, probably for non-canonical address 0xdffffc0000000005: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000028-0x000000000000002f]
CPU: 1 PID: 8036 Comm: syz.2.2147 Tainted: G        W          syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:qdisc_pkt_len include/net/sch_generic.h:831 [inline]
RIP: 0010:fq_codel_change+0x977/0x1090 net/sched/sch_fq_codel.c:436
Code: 24 48 8b 44 24 68 42 0f b6 04 28 84 c0 0f 85 7f 01 00 00 48 8b 44 24 30 ff 08 48 8b 5c 24 10 4d 8d 67 28 4c 89 e0 48 c1 e8 03 <42> 0f b6 04 28 84 c0 0f 85 93 00 00 00 45 8b 34 24 48 8b 44 24 60
RSP: 0018:ffffc90001196fe0 EFLAGS: 00010206
RAX: 0000000000000005 RBX: ffff88811aa8e800 RCX: 0000000000080000
RDX: 0000000000000000 RSI: 0000000000001ca8 RDI: 0000000000001ca9
RBP: ffffc90001197190 R08: ffff8881f5a00000 R09: 00000000000f4ff7
R10: 0000000048470ec9 R11: 0000000000000001 R12: 0000000000000028
R13: dffffc0000000000 R14: 0000000000000003 R15: 0000000000000000
FS:  00007fb351bf06c0(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555561363a08 CR3: 000000015a0b9000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Call Trace:
 <TASK>
 qdisc_change net/sched/sch_api.c:1382 [inline]
 tc_modify_qdisc+0x1654/0x19d0 net/sched/sch_api.c:1720
 rtnetlink_rcv_msg+0xb3b/0xe00 net/core/rtnetlink.c:6153
 netlink_rcv_skb+0x20f/0x460 net/netlink/af_netlink.c:2521
 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:6171
 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
 netlink_unicast+0x8ab/0xa30 net/netlink/af_netlink.c:1345
 netlink_sendmsg+0x8b9/0xbd0 net/netlink/af_netlink.c:1873
 sock_sendmsg_nosec net/socket.c:716 [inline]
 __sock_sendmsg net/socket.c:728 [inline]
 ____sys_sendmsg+0x5cc/0x990 net/socket.c:2508
 ___sys_sendmsg+0x2a2/0x360 net/socket.c:2562
 __sys_sendmsg net/socket.c:2591 [inline]
 __do_sys_sendmsg net/socket.c:2600 [inline]
 __se_sys_sendmsg net/socket.c:2598 [inline]
 __x64_sys_sendmsg+0x205/0x2d0 net/socket.c:2598
 x64_sys_call+0x171/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:47
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fb350d9ce59
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:00007fb351bf0028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fb351016090 RCX: 00007fb350d9ce59
RDX: 000000000000c010 RSI: 0000200000000280 RDI: 000000000000000a
RBP: 00007fb350e32d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb351016128 R14: 00007fb351016090 R15: 00007ffd410a32f8
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:qdisc_pkt_len include/net/sch_generic.h:831 [inline]
RIP: 0010:fq_codel_change+0x977/0x1090 net/sched/sch_fq_codel.c:436
Code: 24 48 8b 44 24 68 42 0f b6 04 28 84 c0 0f 85 7f 01 00 00 48 8b 44 24 30 ff 08 48 8b 5c 24 10 4d 8d 67 28 4c 89 e0 48 c1 e8 03 <42> 0f b6 04 28 84 c0 0f 85 93 00 00 00 45 8b 34 24 48 8b 44 24 60
RSP: 0018:ffffc90001196fe0 EFLAGS: 00010206
RAX: 0000000000000005 RBX: ffff88811aa8e800 RCX: 0000000000080000
RDX: 0000000000000000 RSI: 0000000000001ca8 RDI: 0000000000001ca9
RBP: ffffc90001197190 R08: ffff8881f5a00000 R09: 00000000000f4ff7
R10: 0000000048470ec9 R11: 0000000000000001 R12: 0000000000000028
R13: dffffc0000000000 R14: 0000000000000003 R15: 0000000000000000
FS:  00007fb351bf06c0(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555561363a08 CR3: 000000015a0b9000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
----------------
Code disassembly (best guess):
   0:	24 48                	and    $0x48,%al
   2:	8b 44 24 68          	mov    0x68(%rsp),%eax
   6:	42 0f b6 04 28       	movzbl (%rax,%r13,1),%eax
   b:	84 c0                	test   %al,%al
   d:	0f 85 7f 01 00 00    	jne    0x192
  13:	48 8b 44 24 30       	mov    0x30(%rsp),%rax
  18:	ff 08                	decl   (%rax)
  1a:	48 8b 5c 24 10       	mov    0x10(%rsp),%rbx
  1f:	4d 8d 67 28          	lea    0x28(%r15),%r12
  23:	4c 89 e0             	mov    %r12,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	42 0f b6 04 28       	movzbl (%rax,%r13,1),%eax <-- trapping instruction
  2f:	84 c0                	test   %al,%al
  31:	0f 85 93 00 00 00    	jne    0xca
  37:	45 8b 34 24          	mov    (%r12),%r14d
  3b:	48 8b 44 24 60       	mov    0x60(%rsp),%rax