general protection fault, probably for non-canonical address 0xdffffc000000001d: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x00000000000000e8-0x00000000000000ef] CPU: 1 PID: 4727 Comm: kworker/u4:2 Not tainted 6.4.0-rc7-syzkaller-00215-g6709d4b7bc2e #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023 Workqueue: netns cleanup_net RIP: 0010:qfq_reset_qdisc+0x151/0x440 net/sched/sch_qfq.c:1447 Code: 48 f9 4c 8d 73 50 4c 89 f0 48 c1 e8 03 80 3c 28 00 0f 85 ef 01 00 00 4c 8b 63 50 49 8d bc 24 e8 00 00 00 48 89 f8 48 c1 e8 03 <0f> b6 04 28 84 c0 74 08 3c 03 0f 8e e3 01 00 00 45 8b ac 24 e8 00 RSP: 0018:ffffc9000d847908 EFLAGS: 00010206 RAX: 000000000000001d RBX: ffff88807ab43a00 RCX: 0000000000000000 RDX: ffff88804478bb80 RSI: ffffffff883be979 RDI: 00000000000000e8 RBP: dffffc0000000000 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000004 R11: 0000000000000001 R12: 0000000000000000 R13: ffffed1010101c88 R14: ffff88807ab43a50 R15: ffff88803ec5c000 FS: 0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f089a9b2866 CR3: 000000002ae27000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: qdisc_reset+0xda/0x620 net/sched/sch_generic.c:1022 __qdisc_destroy+0x91/0x450 net/sched/sch_generic.c:1060 qdisc_put+0xd1/0xf0 net/sched/sch_generic.c:1090 dev_shutdown+0x1ce/0x430 net/sched/sch_generic.c:1478 unregister_netdevice_many_notify+0x5fc/0x18c0 net/core/dev.c:10874 unregister_netdevice_many net/core/dev.c:10940 [inline] default_device_exit_batch+0x451/0x5b0 net/core/dev.c:11393 ops_exit_list+0x125/0x170 net/core/net_namespace.c:175 cleanup_net+0x4ee/0xb10 net/core/net_namespace.c:614 process_one_work+0x99a/0x15e0 kernel/workqueue.c:2405 worker_thread+0x67d/0x10c0 kernel/workqueue.c:2552 kthread+0x344/0x440 kernel/kthread.c:379 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:qfq_reset_qdisc+0x151/0x440 net/sched/sch_qfq.c:1447 Code: 48 f9 4c 8d 73 50 4c 89 f0 48 c1 e8 03 80 3c 28 00 0f 85 ef 01 00 00 4c 8b 63 50 49 8d bc 24 e8 00 00 00 48 89 f8 48 c1 e8 03 <0f> b6 04 28 84 c0 74 08 3c 03 0f 8e e3 01 00 00 45 8b ac 24 e8 00 RSP: 0018:ffffc9000d847908 EFLAGS: 00010206 RAX: 000000000000001d RBX: ffff88807ab43a00 RCX: 0000000000000000 RDX: ffff88804478bb80 RSI: ffffffff883be979 RDI: 00000000000000e8 RBP: dffffc0000000000 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000004 R11: 0000000000000001 R12: 0000000000000000 R13: ffffed1010101c88 R14: ffff88807ab43a50 R15: ffff88803ec5c000 FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f089a9b2866 CR3: 000000002a109000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: 48 f9 rex.W stc 2: 4c 8d 73 50 lea 0x50(%rbx),%r14 6: 4c 89 f0 mov %r14,%rax 9: 48 c1 e8 03 shr $0x3,%rax d: 80 3c 28 00 cmpb $0x0,(%rax,%rbp,1) 11: 0f 85 ef 01 00 00 jne 0x206 17: 4c 8b 63 50 mov 0x50(%rbx),%r12 1b: 49 8d bc 24 e8 00 00 lea 0xe8(%r12),%rdi 22: 00 23: 48 89 f8 mov %rdi,%rax 26: 48 c1 e8 03 shr $0x3,%rax * 2a: 0f b6 04 28 movzbl (%rax,%rbp,1),%eax <-- trapping instruction 2e: 84 c0 test %al,%al 30: 74 08 je 0x3a 32: 3c 03 cmp $0x3,%al 34: 0f 8e e3 01 00 00 jle 0x21d 3a: 45 rex.RB 3b: 8b .byte 0x8b 3c: ac lods %ds:(%rsi),%al 3d: 24 e8 and $0xe8,%al