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BUG: KASAN: use-after-free in tipc_sub_unsubscribe+0x22d/0x305 net/tipc/subscr.c:167
Read of size 4 at addr ffff88019cb4a718 by task syz-executor1/26168

CPU: 0 PID: 26168 Comm: syz-executor1 Not tainted 4.16.0+ #4
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+0x1b9/0x294 lib/dump_stack.c:113
 print_address_description+0x6c/0x20b mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report.cold.7+0x242/0x2fe mm/kasan/report.c:412
 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report.c:432
 tipc_sub_unsubscribe+0x22d/0x305 net/tipc/subscr.c:167
 tipc_conn_delete_sub+0x333/0x530 net/tipc/topsrv.c:245
 tipc_topsrv_kern_unsubscr+0x280/0x3f0 net/tipc/topsrv.c:598
 tipc_group_delete+0x2dd/0x3f0 net/tipc/group.c:231
 tipc_sk_leave+0x10e/0x210 net/tipc/socket.c:2800
 tipc_release+0x146/0x1290 net/tipc/socket.c:576
 sock_release+0x96/0x1b0 net/socket.c:594
 sock_close+0x16/0x20 net/socket.c:1149
 __fput+0x34d/0x890 fs/file_table.c:209
 ____fput+0x15/0x20 fs/file_table.c:243
 task_work_run+0x1e4/0x290 kernel/task_work.c:113
 exit_task_work include/linux/task_work.h:22 [inline]
 do_exit+0x1aee/0x2730 kernel/exit.c:865
 do_group_exit+0x16f/0x430 kernel/exit.c:968
 get_signal+0x886/0x1960 kernel/signal.c:2469
 do_signal+0x98/0x2040 arch/x86/kernel/signal.c:810
 exit_to_usermode_loop+0x28a/0x310 arch/x86/entry/common.c:162
 prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:265 [inline]
 do_syscall_64+0x792/0x9d0 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x455329
RSP: 002b:00007fdf987ccc68 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: 0000000000000000 RBX: 00007fdf987cd6d4 RCX: 0000000000455329
RDX: 0000000000000087 RSI: 000000000000010f RDI: 0000000000000015
RBP: 000000000072bea0 R08: 0000000000000127 R09: 0000000000000000
R10: 0000000020000180 R11: 0000000000000246 R12: 0000000000000014
R13: 00000000000005f4 R14: 00000000006fbf80 R15: 0000000000000003

Allocated by task 26168:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 kasan_kmalloc+0xc4/0xe0 mm/kasan/kasan.c:553
 kmem_cache_alloc_trace+0x152/0x780 mm/slab.c:3620
 kmalloc include/linux/slab.h:512 [inline]
 tipc_sub_subscribe+0x25a/0x6b0 net/tipc/subscr.c:143
 tipc_conn_rcv_sub.isra.5+0x42c/0x7e0 net/tipc/topsrv.c:381
 tipc_topsrv_kern_subscr+0x72e/0xad0 net/tipc/topsrv.c:582
 tipc_group_create+0x72e/0xa50 net/tipc/group.c:194
 tipc_sk_join net/tipc/socket.c:2766 [inline]
 tipc_setsockopt+0x2c9/0xd70 net/tipc/socket.c:2881
 __sys_setsockopt+0x1bd/0x390 net/socket.c:1903
 SYSC_setsockopt net/socket.c:1914 [inline]
 SyS_setsockopt+0x34/0x50 net/socket.c:1911
 do_syscall_64+0x29e/0x9d0 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x42/0xb7

Freed by task 26168:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 __kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:521
 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528
 __cache_free mm/slab.c:3498 [inline]
 kfree+0xd9/0x260 mm/slab.c:3813
 tipc_sub_kref_release net/tipc/subscr.c:117 [inline]
 kref_put include/linux/kref.h:70 [inline]
 tipc_sub_put+0x33/0x40 net/tipc/subscr.c:122
 tipc_nametbl_unsubscribe+0x52c/0xaf0 net/tipc/name_table.c:709
 tipc_sub_unsubscribe+0x6d/0x305 net/tipc/subscr.c:166
 tipc_conn_delete_sub+0x333/0x530 net/tipc/topsrv.c:245
 tipc_topsrv_kern_unsubscr+0x280/0x3f0 net/tipc/topsrv.c:598
 tipc_group_delete+0x2dd/0x3f0 net/tipc/group.c:231
 tipc_sk_leave+0x10e/0x210 net/tipc/socket.c:2800
 tipc_release+0x146/0x1290 net/tipc/socket.c:576
 sock_release+0x96/0x1b0 net/socket.c:594
 sock_close+0x16/0x20 net/socket.c:1149
 __fput+0x34d/0x890 fs/file_table.c:209
 ____fput+0x15/0x20 fs/file_table.c:243
 task_work_run+0x1e4/0x290 kernel/task_work.c:113
 exit_task_work include/linux/task_work.h:22 [inline]
 do_exit+0x1aee/0x2730 kernel/exit.c:865
 do_group_exit+0x16f/0x430 kernel/exit.c:968
 get_signal+0x886/0x1960 kernel/signal.c:2469
 do_signal+0x98/0x2040 arch/x86/kernel/signal.c:810
 exit_to_usermode_loop+0x28a/0x310 arch/x86/entry/common.c:162
 prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:265 [inline]
 do_syscall_64+0x792/0x9d0 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7

The buggy address belongs to the object at ffff88019cb4a680
 which belongs to the cache kmalloc-256 of size 256
The buggy address is located 152 bytes inside of
 256-byte region [ffff88019cb4a680, ffff88019cb4a780)
The buggy address belongs to the page:
page:ffffea000672d280 count:1 mapcount:0 mapping:ffff88019cb4a040 index:0x0
flags: 0x2fffc0000000100(slab)
raw: 02fffc0000000100 ffff88019cb4a040 0000000000000000 000000010000000c
raw: ffffea00074491a0 ffffea00067289a0 ffff8801dac007c0 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88019cb4a600: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 ffff88019cb4a680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88019cb4a700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                            ^
 ffff88019cb4a780: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00
 ffff88019cb4a800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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