general protection fault, probably for non-canonical address 0xdffffc000000001d: 0000 [#1] PREEMPT SMP KASAN PTI KASAN: null-ptr-deref in range [0x00000000000000e8-0x00000000000000ef] CPU: 0 PID: 2644 Comm: kworker/u4:6 Not tainted 6.8.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024 Workqueue: netns cleanup_net RIP: 0010:qfq_reset_qdisc+0x101/0x240 net/sched/sch_qfq.c:1471 Code: 50 4d 89 fd 49 c1 ed 03 43 80 7c 35 00 00 74 08 4c 89 ff e8 f1 b7 85 f8 49 8b 2f b8 e8 00 00 00 48 01 c5 48 89 e8 48 c1 e8 03 <42> 0f b6 04 30 84 c0 75 7a 8b 6d 00 31 ff 89 ee e8 aa 9e 23 f8 85 RSP: 0000:ffffc900140d76f0 EFLAGS: 00010206 RAX: 000000000000001d RBX: ffff88803fc90500 RCX: ffff88801e483b80 RDX: ffff88801e483b80 RSI: 0000000000000004 RDI: ffff88806f9e82d0 RBP: 00000000000000e9 R08: ffffffff896fd1c6 R09: 1ffffffff1f0acb5 R10: dffffc0000000000 R11: ffffffff896fd170 R12: ffff88806f9e82c0 R13: 1ffff11007f920aa R14: dffffc0000000000 R15: ffff88803fc90550 FS: 0000000000000000(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000f74b1408 CR3: 000000002db38000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: qdisc_reset+0x103/0x580 net/sched/sch_generic.c:1024 __qdisc_destroy+0x120/0x3e0 net/sched/sch_generic.c:1063 qdisc_put net/sched/sch_generic.c:1094 [inline] dev_shutdown+0x357/0x440 net/sched/sch_generic.c:1482 unregister_netdevice_many_notify+0x9a2/0x1740 net/core/dev.c:11073 unregister_netdevice_many net/core/dev.c:11139 [inline] default_device_exit_batch+0x955/0x9d0 net/core/dev.c:11619 ops_exit_list net/core/net_namespace.c:175 [inline] cleanup_net+0x775/0xb90 net/core/net_namespace.c:618 process_one_work kernel/workqueue.c:2633 [inline] process_scheduled_works+0x913/0x1420 kernel/workqueue.c:2706 worker_thread+0xa5f/0x1000 kernel/workqueue.c:2787 kthread+0x2ef/0x390 kernel/kthread.c:388 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:242 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:qfq_reset_qdisc+0x101/0x240 net/sched/sch_qfq.c:1471 Code: 50 4d 89 fd 49 c1 ed 03 43 80 7c 35 00 00 74 08 4c 89 ff e8 f1 b7 85 f8 49 8b 2f b8 e8 00 00 00 48 01 c5 48 89 e8 48 c1 e8 03 <42> 0f b6 04 30 84 c0 75 7a 8b 6d 00 31 ff 89 ee e8 aa 9e 23 f8 85 RSP: 0000:ffffc900140d76f0 EFLAGS: 00010206 RAX: 000000000000001d RBX: ffff88803fc90500 RCX: ffff88801e483b80 RDX: ffff88801e483b80 RSI: 0000000000000004 RDI: ffff88806f9e82d0 RBP: 00000000000000e9 R08: ffffffff896fd1c6 R09: 1ffffffff1f0acb5 R10: dffffc0000000000 R11: ffffffff896fd170 R12: ffff88806f9e82c0 R13: 1ffff11007f920aa R14: dffffc0000000000 R15: ffff88803fc90550 FS: 0000000000000000(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000f74b1408 CR3: 000000002e1a6000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: 50 push %rax 1: 4d 89 fd mov %r15,%r13 4: 49 c1 ed 03 shr $0x3,%r13 8: 43 80 7c 35 00 00 cmpb $0x0,0x0(%r13,%r14,1) e: 74 08 je 0x18 10: 4c 89 ff mov %r15,%rdi 13: e8 f1 b7 85 f8 call 0xf885b809 18: 49 8b 2f mov (%r15),%rbp 1b: b8 e8 00 00 00 mov $0xe8,%eax 20: 48 01 c5 add %rax,%rbp 23: 48 89 e8 mov %rbp,%rax 26: 48 c1 e8 03 shr $0x3,%rax * 2a: 42 0f b6 04 30 movzbl (%rax,%r14,1),%eax <-- trapping instruction 2f: 84 c0 test %al,%al 31: 75 7a jne 0xad 33: 8b 6d 00 mov 0x0(%rbp),%ebp 36: 31 ff xor %edi,%edi 38: 89 ee mov %ebp,%esi 3a: e8 aa 9e 23 f8 call 0xf8239ee9 3f: 85 .byte 0x85