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BUG: KASAN: slab-out-of-bounds in fl6_update_dst+0x2bb/0x2c0 net/ipv6/exthdrs.c:1356
Read of size 16 at addr ffff8880900c0388 by task syz-executor.0/468

CPU: 0 PID: 468 Comm: syz-executor.0 Not tainted 5.7.0-rc7-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+0x188/0x20d lib/dump_stack.c:118
 print_address_description.constprop.0.cold+0xd3/0x413 mm/kasan/report.c:382
 __kasan_report.cold+0x20/0x38 mm/kasan/report.c:511
 kasan_report+0x33/0x50 mm/kasan/common.c:625
 fl6_update_dst+0x2bb/0x2c0 net/ipv6/exthdrs.c:1356
 sctp_v6_get_dst+0x5e7/0x1c30 net/sctp/ipv6.c:276
 sctp_transport_route+0x125/0x350 net/sctp/transport.c:297
 sctp_assoc_add_peer+0x5a0/0x1030 net/sctp/associola.c:659
 sctp_connect_new_asoc+0x19b/0x580 net/sctp/socket.c:1099
 __sctp_connect+0x430/0xc70 net/sctp/socket.c:1197
 __sctp_setsockopt_connectx+0x12d/0x180 net/sctp/socket.c:1343
 sctp_setsockopt_connectx net/sctp/socket.c:1375 [inline]
 sctp_setsockopt net/sctp/socket.c:4720 [inline]
 sctp_setsockopt+0x15a1/0x7090 net/sctp/socket.c:4677
 __sys_setsockopt+0x248/0x480 net/socket.c:2127
 __do_sys_setsockopt net/socket.c:2143 [inline]
 __se_sys_setsockopt net/socket.c:2140 [inline]
 __x64_sys_setsockopt+0xba/0x150 net/socket.c:2140
 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x49/0xb3
RIP: 0033:0x45ca69
Code: 0d b7 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 db b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f1613c53c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000504900 RCX: 000000000045ca69
RDX: 000000000000006e RSI: 0000000000000084 RDI: 0000000000000003
RBP: 000000000078bf00 R08: 000000000000001c R09: 0000000000000000
R10: 0000000020000080 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000aea R14: 00000000004d75e0 R15: 00007f1613c546d4

Allocated by task 468:
 save_stack+0x1b/0x40 mm/kasan/common.c:49
 set_track mm/kasan/common.c:57 [inline]
 __kasan_kmalloc mm/kasan/common.c:495 [inline]
 __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:468
 __do_kmalloc mm/slab.c:3656 [inline]
 __kmalloc+0x161/0x7a0 mm/slab.c:3665
 kmalloc include/linux/slab.h:560 [inline]
 sock_kmalloc net/core/sock.c:2255 [inline]
 sock_kmalloc+0xb5/0x100 net/core/sock.c:2246
 ipv6_renew_options+0x274/0x940 net/ipv6/exthdrs.c:1275
 do_ipv6_setsockopt.isra.0+0x2db4/0x4330 net/ipv6/ipv6_sockglue.c:471
 ipv6_setsockopt+0xfb/0x180 net/ipv6/ipv6_sockglue.c:900
 sctp_setsockopt+0x13e/0x7090 net/sctp/socket.c:4692
 __sys_setsockopt+0x248/0x480 net/socket.c:2127
 __do_sys_setsockopt net/socket.c:2143 [inline]
 __se_sys_setsockopt net/socket.c:2140 [inline]
 __x64_sys_setsockopt+0xba/0x150 net/socket.c:2140
 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x49/0xb3

Freed by task 411:
 save_stack+0x1b/0x40 mm/kasan/common.c:49
 set_track mm/kasan/common.c:57 [inline]
 kasan_set_free_info mm/kasan/common.c:317 [inline]
 __kasan_slab_free+0xf7/0x140 mm/kasan/common.c:456
 __cache_free mm/slab.c:3426 [inline]
 kfree+0x109/0x2b0 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+0x1e7/0x2e0 lib/kobject.c:739
 kset_unregister lib/kobject.c:881 [inline]
 kset_unregister+0x27/0x30 lib/kobject.c:876
 remove_queue_kobjects net/core/net-sysfs.c:1702 [inline]
 netdev_unregister_kobject+0x17f/0x1e0 net/core/net-sysfs.c:1850
 rollback_registered_many+0x9a9/0xe70 net/core/dev.c:8982
 unregister_netdevice_many.part.0+0x16/0x1e0 net/core/dev.c:10106
 unregister_netdevice_many+0x36/0x50 net/core/dev.c:10105
 sit_exit_batch_net+0x537/0x710 net/ipv6/sit.c:1943
 ops_exit_list.isra.0+0x103/0x150 net/core/net_namespace.c:189
 cleanup_net+0x511/0xa50 net/core/net_namespace.c:603
 process_one_work+0x965/0x16a0 kernel/workqueue.c:2268
 worker_thread+0x96/0xe20 kernel/workqueue.c:2414
 kthread+0x388/0x470 kernel/kthread.c:268
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:351

The buggy address belongs to the object at ffff8880900c0300
 which belongs to the cache kmalloc-192 of size 192
The buggy address is located 136 bytes inside of
 192-byte region [ffff8880900c0300, ffff8880900c03c0)
The buggy address belongs to the page:
page:ffffea0002403000 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0
flags: 0xfffe0000000200(slab)
raw: 00fffe0000000200 ffffea0002921e48 ffffea00025d5508 ffff8880aa000000
raw: 0000000000000000 ffff8880900c0000 0000000100000010 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880900c0280: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 ffff8880900c0300: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8880900c0380: 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                      ^
 ffff8880900c0400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880900c0480: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
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