general protection fault in hfsc_unbind_tcf

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit:    770fbb32 Add linux-next specific files for 20200228
git tree:       linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=1433a7c3e00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=576314276bce4ad5
dashboard link: https://syzkaller.appspot.com/bug?extid=05e596c4433eae36069b
compiler:       gcc (GCC) 9.0.0 20181231 (experimental)

Unfortunately, I don't have any reproducer for this crash yet.

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+05e596c4433eae36069b@xxxxxxxxxxxxxxxxxxxxxxxxx

general protection fault, probably for non-canonical address 0xfbd5a5d5a000000b: 0000 [#1] PREEMPT SMP KASAN
KASAN: maybe wild-memory-access in range [0xdead4ead00000058-0xdead4ead0000005f]
CPU: 1 PID: 1558 Comm: kworker/u4:0 Not tainted 5.6.0-rc3-next-20200228-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: netns cleanup_net
RIP: 0010:hfsc_unbind_tcf+0x1e/0x40 net/sched/sch_hfsc.c:1238
Code: fb eb af e8 d4 d4 79 fb eb de 66 90 53 48 89 f3 e8 27 b4 3c fb 48 8d 7b 58 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84 c0 74 04 3c 03 7e 06 83 6b 58 01 5b c3 e8 8b d4 79
RSP: 0018:ffffc90002427630 EFLAGS: 00010a02
RAX: dffffc0000000000 RBX: dead4ead00000000 RCX: ffffffff86419d1e
RDX: 1bd5a9d5a000000b RSI: ffffffff8635e159 RDI: dead4ead00000058
RBP: ffff8880907d9300 R08: ffff888093d3c3c0 R09: ffffed10120fb263
R10: ffffed10120fb262 R11: ffff8880907d9317 R12: dead4ead00000000
R13: ffff88809e0a9000 R14: dffffc0000000000 R15: ffffffff8a86bbe0
FS:  0000000000000000(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000002000c2c0 CR3: 000000006894c000 CR4: 00000000001426e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 __tcf_unbind_filter include/net/pkt_cls.h:176 [inline]
 tcf_unbind_filter include/net/pkt_cls.h:186 [inline]
 route4_destroy+0x36b/0x820 net/sched/cls_route.c:297
 tcf_proto_destroy+0x6e/0x310 net/sched/cls_api.c:296
 tcf_proto_put+0x8c/0xc0 net/sched/cls_api.c:308
 tcf_chain_flush+0x266/0x390 net/sched/cls_api.c:600
 tcf_block_flush_all_chains net/sched/cls_api.c:1052 [inline]
 __tcf_block_put+0x1a4/0x540 net/sched/cls_api.c:1214
 tcf_block_put_ext net/sched/cls_api.c:1414 [inline]
 tcf_block_put+0xb3/0x100 net/sched/cls_api.c:1429
 hfsc_destroy_qdisc+0xe0/0x280 net/sched/sch_hfsc.c:1501
 qdisc_destroy+0x118/0x690 net/sched/sch_generic.c:958
 qdisc_put+0xcd/0xe0 net/sched/sch_generic.c:985
 dev_shutdown+0x2b5/0x492 net/sched/sch_generic.c:1311
 rollback_registered_many+0x603/0xe70 net/core/dev.c:8802
 unregister_netdevice_many.part.0+0x16/0x1e0 net/core/dev.c:9965
 unregister_netdevice_many net/core/dev.c:9964 [inline]
 default_device_exit_batch+0x311/0x3d0 net/core/dev.c:10448
 ops_exit_list.isra.0+0x103/0x150 net/core/net_namespace.c:175
 cleanup_net+0x511/0xa50 net/core/net_namespace.c:589
 process_one_work+0x94b/0x1690 kernel/workqueue.c:2266
 worker_thread+0x96/0xe20 kernel/workqueue.c:2412
 kthread+0x357/0x430 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
Modules linked in:
---[ end trace 4e5544fa17900677 ]---
RIP: 0010:hfsc_unbind_tcf+0x1e/0x40 net/sched/sch_hfsc.c:1238
Code: fb eb af e8 d4 d4 79 fb eb de 66 90 53 48 89 f3 e8 27 b4 3c fb 48 8d 7b 58 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84 c0 74 04 3c 03 7e 06 83 6b 58 01 5b c3 e8 8b d4 79
RSP: 0018:ffffc90002427630 EFLAGS: 00010a02
RAX: dffffc0000000000 RBX: dead4ead00000000 RCX: ffffffff86419d1e
RDX: 1bd5a9d5a000000b RSI: ffffffff8635e159 RDI: dead4ead00000058
RBP: ffff8880907d9300 R08: ffff888093d3c3c0 R09: ffffed10120fb263
R10: ffffed10120fb262 R11: ffff8880907d9317 R12: dead4ead00000000
R13: ffff88809e0a9000 R14: dffffc0000000000 R15: ffffffff8a86bbe0
FS:  0000000000000000(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000002736978 CR3: 0000000091659000 CR4: 00000000001426e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


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