general protection fault, probably for non-canonical address 0xdffffc000000001d: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x00000000000000e8-0x00000000000000ef] CPU: 0 PID: 3940 Comm: kworker/u4:5 Not tainted 6.6.0-rc5-syzkaller-00192-g2d1c882d4434 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023 Workqueue: netns cleanup_net RIP: 0010:qfq_reset_qdisc+0x117/0x420 net/sched/sch_qfq.c:1471 Code: 62 27 f9 4c 8d 6b 50 4c 89 e8 48 c1 e8 03 80 3c 28 00 0f 85 1a 02 00 00 4c 8b 73 50 49 8d be e8 00 00 00 48 89 f8 48 c1 e8 03 <0f> b6 04 28 84 c0 74 08 3c 03 0f 8e 0f 02 00 00 45 8b be e8 00 00 RSP: 0018:ffffc900163a78b8 EFLAGS: 00010206 RAX: 000000000000001d RBX: ffff8880465dc900 RCX: 0000000000000000 RDX: ffff88802e628000 RSI: ffffffff886063e0 RDI: 00000000000000e8 RBP: dffffc0000000000 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000004 R11: 0000000000000000 R12: ffff88808346c2d0 R13: ffff8880465dc950 R14: 0000000000000000 R15: ffffed101068d85a FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f3335d46ee0 CR3: 0000000074498000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: qdisc_reset+0xd8/0x620 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+0x5bd/0x1a20 net/core/dev.c:10932 unregister_netdevice_many net/core/dev.c:10998 [inline] default_device_exit_batch+0x584/0x740 net/core/dev.c:11457 ops_exit_list+0x125/0x170 net/core/net_namespace.c:175 cleanup_net+0x505/0xb20 net/core/net_namespace.c:614 process_one_work+0x884/0x15c0 kernel/workqueue.c:2630 process_scheduled_works kernel/workqueue.c:2703 [inline] worker_thread+0x8b9/0x1290 kernel/workqueue.c:2784 kthread+0x33c/0x440 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:qfq_reset_qdisc+0x117/0x420 net/sched/sch_qfq.c:1471 Code: 62 27 f9 4c 8d 6b 50 4c 89 e8 48 c1 e8 03 80 3c 28 00 0f 85 1a 02 00 00 4c 8b 73 50 49 8d be e8 00 00 00 48 89 f8 48 c1 e8 03 <0f> b6 04 28 84 c0 74 08 3c 03 0f 8e 0f 02 00 00 45 8b be e8 00 00 RSP: 0018:ffffc900163a78b8 EFLAGS: 00010206 RAX: 000000000000001d RBX: ffff8880465dc900 RCX: 0000000000000000 RDX: ffff88802e628000 RSI: ffffffff886063e0 RDI: 00000000000000e8 RBP: dffffc0000000000 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000004 R11: 0000000000000000 R12: ffff88808346c2d0 R13: ffff8880465dc950 R14: 0000000000000000 R15: ffffed101068d85a FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f3335d46ee0 CR3: 000000002541b000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess), 2 bytes skipped: 0: f9 stc 1: 4c 8d 6b 50 lea 0x50(%rbx),%r13 5: 4c 89 e8 mov %r13,%rax 8: 48 c1 e8 03 shr $0x3,%rax c: 80 3c 28 00 cmpb $0x0,(%rax,%rbp,1) 10: 0f 85 1a 02 00 00 jne 0x230 16: 4c 8b 73 50 mov 0x50(%rbx),%r14 1a: 49 8d be e8 00 00 00 lea 0xe8(%r14),%rdi 21: 48 89 f8 mov %rdi,%rax 24: 48 c1 e8 03 shr $0x3,%rax * 28: 0f b6 04 28 movzbl (%rax,%rbp,1),%eax <-- trapping instruction 2c: 84 c0 test %al,%al 2e: 74 08 je 0x38 30: 3c 03 cmp $0x3,%al 32: 0f 8e 0f 02 00 00 jle 0x247 38: 45 rex.RB 39: 8b .byte 0x8b 3a: be .byte 0xbe 3b: e8 .byte 0xe8