==================================================================
BUG: KASAN: slab-out-of-bounds in fl6_update_dst+0x2bb/0x2c0 net/ipv6/exthdrs.c:1356
Read of size 16 at addr ffff888093f36658 by task syz-executor.4/21612

CPU: 1 PID: 21612 Comm: syz-executor.4 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_sendmsg_new_asoc net/sctp/socket.c:1701 [inline]
 sctp_sendmsg+0x1396/0x1f30 net/sctp/socket.c:2011
 inet_sendmsg+0x99/0xe0 net/ipv4/af_inet.c:814
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:672
 __sys_sendto+0x219/0x330 net/socket.c:1995
 __do_sys_sendto net/socket.c:2007 [inline]
 __se_sys_sendto net/socket.c:2003 [inline]
 __x64_sys_sendto+0xdd/0x1b0 net/socket.c:2003
 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x49/0xb3
RIP: 0033:0x45cb19
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:00007ffafa727c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00000000005028c0 RCX: 000000000045cb19
RDX: 0000000000000016 RSI: 0000000020000000 RDI: 0000000000000003
RBP: 000000000078bf00 R08: 00000000200000c0 R09: 000000000000001c
R10: 0000000020004886 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000a4b R14: 00000000004cd312 R15: 00007ffafa7286d4

Allocated by task 21612:
 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 20997:
 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]
 kfree+0x109/0x2b0 mm/slab.c:3757
 tomoyo_path_perm+0x236/0x400 security/tomoyo/file.c:842
 tomoyo_path_symlink+0x94/0xe0 security/tomoyo/tomoyo.c:206
 security_path_symlink+0xfb/0x160 security/security.c:1104
 do_symlinkat+0x124/0x280 fs/namei.c:3964
 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x49/0xb3

The buggy address belongs to the object at ffff888093f36600
 which belongs to the cache kmalloc-96 of size 96
The buggy address is located 88 bytes inside of
 96-byte region [ffff888093f36600, ffff888093f36660)
The buggy address belongs to the page:
page:ffffea00024fcd80 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888093f36480
flags: 0xfffe0000000200(slab)
raw: 00fffe0000000200 ffffea00013be448 ffffea00029a0948 ffff8880aa000540
raw: ffff888093f36480 ffff888093f36000 000000010000001d 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff888093f36500: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
 ffff888093f36580: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
>ffff888093f36600: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc
                                                       ^
 ffff888093f36680: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
 ffff888093f36700: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
==================================================================