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BUG: KASAN: use-after-free in sock_net include/net/sock.h:2454 [inline]
BUG: KASAN: use-after-free in sctp_hash_cmp+0x1d4/0x220 net/sctp/input.c:879
Read of size 8 at addr ffff8880a7dcedb0 by task syz-executor.3/3340

CPU: 0 PID: 3340 Comm: syz-executor.3 Not tainted 5.3.0-rc3+ #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+0x113/0x167 lib/dump_stack.c:113
 print_address_description.cold.8+0x9/0x318 mm/kasan/report.c:351
 __kasan_report.cold.9+0x1b/0x3f mm/kasan/report.c:482
 kasan_report+0x12/0x17 mm/kasan/common.c:612
 __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:132
 sock_net include/net/sock.h:2454 [inline]
 sctp_hash_cmp+0x1d4/0x220 net/sctp/input.c:879
 __rhashtable_lookup include/linux/rhashtable.h:608 [inline]
 rhltable_lookup include/linux/rhashtable.h:695 [inline]
 sctp_hash_transport+0x407/0x1790 net/sctp/input.c:939
 sctp_assoc_add_peer+0x886/0xe40 net/sctp/associola.c:710
 sctp_connect_new_asoc+0x145/0x4b0 net/sctp/socket.c:1079
 __sctp_connect+0x36a/0xaf0 net/sctp/socket.c:1177
 sctp_connect net/sctp/socket.c:4742 [inline]
 sctp_inet_connect+0x109/0x170 net/sctp/socket.c:4757
 __sys_connect+0x20d/0x2d0 net/socket.c:1828
 __do_sys_connect net/socket.c:1839 [inline]
 __se_sys_connect net/socket.c:1836 [inline]
 __ia32_sys_connect+0x6d/0xb0 net/socket.c:1836
 do_syscall_32_irqs_on arch/x86/entry/common.c:332 [inline]
 do_fast_syscall_32+0x235/0xb3b arch/x86/entry/common.c:403
 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139
RIP: 0023:0xf7f42a09
Code: 96 98 00 eb ce 8b 04 24 c3 8b 1c 24 c3 8b 34 24 c3 8b 3c 24 c3 90 90 90 90 90 90 90 90 90 90 90 90 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 002b:00000000f7f3e0cc EFLAGS: 00000296 ORIG_RAX: 000000000000016a
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000020001200
RDX: 0000000000000010 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000

Allocated by task 3339:
 save_stack+0x21/0x90 mm/kasan/common.c:69
 set_track mm/kasan/common.c:77 [inline]
 __kasan_kmalloc.constprop.9+0xc7/0xd0 mm/kasan/common.c:487
 kasan_slab_alloc+0x12/0x20 mm/kasan/common.c:495
 slab_post_alloc_hook mm/slab.h:520 [inline]
 slab_alloc mm/slab.c:3319 [inline]
 kmem_cache_alloc+0x121/0x750 mm/slab.c:3483
 sk_prot_alloc+0x5d/0x250 net/core/sock.c:1597
 sk_alloc+0x30/0xc70 net/core/sock.c:1657
 inet6_create+0x268/0xde0 net/ipv6/af_inet6.c:180
 __sock_create+0x262/0x540 net/socket.c:1418
 sock_create net/socket.c:1469 [inline]
 __sys_socket+0xd7/0x1c0 net/socket.c:1511
 __do_sys_socket net/socket.c:1520 [inline]
 __se_sys_socket net/socket.c:1518 [inline]
 __ia32_sys_socket+0x6e/0xb0 net/socket.c:1518
 do_syscall_32_irqs_on arch/x86/entry/common.c:332 [inline]
 do_fast_syscall_32+0x235/0xb3b arch/x86/entry/common.c:403
 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139

Freed by task 3335:
 save_stack+0x21/0x90 mm/kasan/common.c:69
 set_track mm/kasan/common.c:77 [inline]
 __kasan_slab_free+0x102/0x150 mm/kasan/common.c:449
 kasan_slab_free+0xe/0x10 mm/kasan/common.c:457
 __cache_free mm/slab.c:3425 [inline]
 kmem_cache_free+0x83/0x320 mm/slab.c:3693
 sk_prot_free net/core/sock.c:1638 [inline]
 __sk_destruct+0x3c9/0x580 net/core/sock.c:1726
 sk_destruct+0x5a/0x70 net/core/sock.c:1734
 __sk_free+0xc7/0x2a0 net/core/sock.c:1745
 sk_free+0x23/0x30 net/core/sock.c:1756
 sock_put include/net/sock.h:1725 [inline]
 sctp_close+0x457/0x760 net/sctp/socket.c:1543
 inet_release+0xc1/0x1c0 net/ipv4/af_inet.c:427
 inet6_release+0x46/0x60 net/ipv6/af_inet6.c:470
 __sock_release+0xc2/0x270 net/socket.c:590
 sock_close+0x13/0x20 net/socket.c:1268
 __fput+0x25a/0x770 fs/file_table.c:280
 ____fput+0x9/0x10 fs/file_table.c:313
 task_work_run+0x108/0x180 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_usermode_loop+0x24e/0x2e0 arch/x86/entry/common.c:163
 prepare_exit_to_usermode arch/x86/entry/common.c:194 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:274 [inline]
 do_syscall_32_irqs_on arch/x86/entry/common.c:347 [inline]
 do_fast_syscall_32+0x90e/0xb3b arch/x86/entry/common.c:403
 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139

The buggy address belongs to the object at ffff8880a7dced80
 which belongs to the cache SCTPv6(49:syz1) of size 1952
The buggy address is located 48 bytes inside of
 1952-byte region [ffff8880a7dced80, ffff8880a7dcf520)
The buggy address belongs to the page:
page:ffffea00029f7380 refcount:1 mapcount:0 mapping:ffff888091c5ce00 index:0x0 compound_mapcount: 0
flags: 0x1fffc0000010200(slab|head)
raw: 01fffc0000010200 ffffea000242a108 ffffea0002a09a88 ffff888091c5ce00
raw: 0000000000000000 ffff8880a7dce540 0000000100000003 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880a7dcec80: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
 ffff8880a7dced00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8880a7dced80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                     ^
 ffff8880a7dcee00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880a7dcee80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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