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BUG: KASAN: use-after-free in tcindex_set_parms+0x1690/0x1b90 net/sched/cls_tcindex.c:455
Write of size 16 at addr ffff8880a77a1ab8 by task syz-executor.1/8528

CPU: 0 PID: 8528 Comm: syz-executor.1 Not tainted 5.5.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x128/0x182 lib/dump_stack.c:118
 print_address_description.constprop.8.cold.10+0x9/0x317 mm/kasan/report.c:374
 __kasan_report.cold.11+0x1c/0x34 mm/kasan/report.c:506
 kasan_report+0xe/0x20 mm/kasan/common.c:639
 tcindex_set_parms+0x1690/0x1b90 net/sched/cls_tcindex.c:455
 tcindex_change+0x1c2/0x280 net/sched/cls_tcindex.c:519
 tc_new_tfilter+0xffa/0x1da0 net/sched/cls_api.c:2103
 rtnetlink_rcv_msg+0x60c/0x8c0 net/core/rtnetlink.c:5429
 netlink_rcv_skb+0x119/0x340 net/netlink/af_netlink.c:2477
 netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline]
 netlink_unicast+0x434/0x630 net/netlink/af_netlink.c:1328
 netlink_sendmsg+0x714/0xc60 net/netlink/af_netlink.c:1917
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg+0xac/0xe0 net/socket.c:672
 ____sys_sendmsg+0x54e/0x750 net/socket.c:2343
 ___sys_sendmsg+0xe4/0x160 net/socket.c:2397
 __sys_sendmsg+0xce/0x170 net/socket.c:2430
 do_syscall_64+0xc6/0x5e0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45c4a9
Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f1f8a09fc78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f1f8a0a06d4 RCX: 000000000045c4a9
RDX: 0000000000000000 RSI: 00000000200001c0 RDI: 0000000000000003
RBP: 000000000076bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000000009fa R14: 00000000004cc777 R15: 000000000076bf2c

Allocated by task 8330:
 save_stack+0x19/0x80 mm/kasan/common.c:72
 set_track mm/kasan/common.c:80 [inline]
 __kasan_kmalloc.constprop.17+0xc1/0xd0 mm/kasan/common.c:513
 kmem_cache_alloc_trace+0x156/0x780 mm/slab.c:3551
 kmalloc include/linux/slab.h:556 [inline]
 kzalloc include/linux/slab.h:670 [inline]
 kset_create lib/kobject.c:955 [inline]
 kset_create_and_add+0x47/0x160 lib/kobject.c:998
 register_queue_kobjects net/core/net-sysfs.c:1528 [inline]
 netdev_register_kobject+0x18f/0x350 net/core/net-sysfs.c:1759
 register_netdevice+0x464/0xe30 net/core/dev.c:9380
 register_netdev+0x15/0x30 net/core/dev.c:9504
 ip6_tnl_init_net+0x420/0x6a0 net/ipv6/ip6_tunnel.c:2242
 ops_init+0x92/0x350 net/core/net_namespace.c:137
 setup_net+0x2c0/0x780 net/core/net_namespace.c:327
 copy_net_ns+0x24d/0x490 net/core/net_namespace.c:468
 create_new_namespaces+0x491/0x900 kernel/nsproxy.c:108
 unshare_nsproxy_namespaces+0x82/0x1a0 kernel/nsproxy.c:229
 ksys_unshare+0x321/0x6a0 kernel/fork.c:2955
 __do_sys_unshare kernel/fork.c:3023 [inline]
 __se_sys_unshare kernel/fork.c:3021 [inline]
 __x64_sys_unshare+0x28/0x40 kernel/fork.c:3021
 do_syscall_64+0xc6/0x5e0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 21:
 save_stack+0x19/0x80 mm/kasan/common.c:72
 set_track mm/kasan/common.c:80 [inline]
 kasan_set_free_info mm/kasan/common.c:335 [inline]
 __kasan_slab_free+0xf7/0x140 mm/kasan/common.c:474
 __cache_free mm/slab.c:3426 [inline]
 kfree+0x107/0x2b0 mm/slab.c:3757
 kobject_cleanup lib/kobject.c:693 [inline]
 kobject_release lib/kobject.c:722 [inline]
 kref_put include/linux/kref.h:65 [inline]
 kobject_put+0x14b/0x210 lib/kobject.c:739
 remove_queue_kobjects net/core/net-sysfs.c:1569 [inline]
 netdev_unregister_kobject+0x167/0x1d0 net/core/net-sysfs.c:1717
 rollback_registered_many+0x7e4/0xd10 net/core/dev.c:8847
 unregister_netdevice_many+0x39/0x1f0 net/core/dev.c:9976
 ip6_tnl_exit_batch_net+0x35b/0x510 net/ipv6/ip6_tunnel.c:2265
 cleanup_net+0x45f/0x910 net/core/net_namespace.c:589
 process_one_work+0x903/0x15c0 kernel/workqueue.c:2264
 worker_thread+0x82/0xb50 kernel/workqueue.c:2410
 kthread+0x31d/0x3e0 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352

The buggy address belongs to the object at ffff8880a77a1a00
 which belongs to the cache kmalloc-192 of size 192
The buggy address is located 184 bytes inside of
 192-byte region [ffff8880a77a1a00, ffff8880a77a1ac0)
The buggy address belongs to the page:
page:ffffea00029de840 refcount:1 mapcount:0 mapping:ffff8880aa400000 index:0x0
raw: 00fffe0000000200 ffffea00029d2f08 ffffea00029b0088 ffff8880aa400000
raw: 0000000000000000 ffff8880a77a1000 0000000100000010 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880a77a1980: 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880a77a1a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8880a77a1a80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
                                        ^
 ffff8880a77a1b00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8880a77a1b80: 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc
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