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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 ffff8880549d50d8 by task syz-executor.1/23372

CPU: 1 PID: 23372 Comm: syz-executor.1 Not tainted 5.7.0-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+0x188/0x20d lib/dump_stack.c:118
 print_address_description.constprop.0.cold+0xd3/0x413 mm/kasan/report.c:383
 __kasan_report mm/kasan/report.c:513 [inline]
 kasan_report.cold+0x1f/0x37 mm/kasan/report.c:530
 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_connect net/sctp/socket.c:4915 [inline]
 sctp_inet_connect+0x14b/0x1b0 net/sctp/socket.c:4930
 __sys_connect_file+0x155/0x1a0 net/socket.c:1854
 __sys_connect+0x160/0x190 net/socket.c:1871
 __do_sys_connect net/socket.c:1882 [inline]
 __se_sys_connect net/socket.c:1879 [inline]
 __x64_sys_connect+0x6f/0xb0 net/socket.c:1879
 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x49/0xb3
RIP: 0033:0x45ca59
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:00007f03ab926c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002a
RAX: ffffffffffffffda RBX: 00000000004db420 RCX: 000000000045ca59
RDX: 000000000000001c RSI: 0000000020000080 RDI: 0000000000000003
RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000089 R14: 00000000004c3458 R15: 00007f03ab9276d4

Allocated by task 23372:
 save_stack+0x1b/0x40 mm/kasan/common.c:48
 set_track mm/kasan/common.c:56 [inline]
 __kasan_kmalloc mm/kasan/common.c:494 [inline]
 __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:467
 __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 12864:
 save_stack+0x1b/0x40 mm/kasan/common.c:48
 set_track mm/kasan/common.c:56 [inline]
 kasan_set_free_info mm/kasan/common.c:316 [inline]
 __kasan_slab_free+0xf7/0x140 mm/kasan/common.c:455
 __cache_free mm/slab.c:3426 [inline]
 kmem_cache_free_bulk+0x7d/0x280 mm/slab.c:3721
 kfree_bulk include/linux/slab.h:412 [inline]
 kfree_rcu_work+0x1a1/0x480 kernel/rcu/tree.c:3051
 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 ffff8880549d5000
 which belongs to the cache kmalloc-256 of size 256
The buggy address is located 216 bytes inside of
 256-byte region [ffff8880549d5000, ffff8880549d5100)
The buggy address belongs to the page:
page:ffffea0001527540 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff8880549d5c00
flags: 0xfffe0000000200(slab)
raw: 00fffe0000000200 ffffea00029adf88 ffffea00022ef848 ffff8880aa0008c0
raw: ffff8880549d5c00 ffff8880549d5000 0000000100000006 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880549d4f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880549d5000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8880549d5080: 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc
                                                    ^
 ffff8880549d5100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880549d5180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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