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BUG: KASAN: use-after-free in ex_handler_refcount+0x164/0x1a0 arch/x86/mm/extable.c:49
Write of size 4 at addr ffff888095cabf80 by task kworker/u4:5/7409

CPU: 0 PID: 7409 Comm: kworker/u4:5 Not tainted 4.14.174-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: tipc_rcv tipc_recv_work
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x13e/0x194 lib/dump_stack.c:58
 print_address_description.cold+0x7c/0x1e2 mm/kasan/report.c:252
 kasan_report_error mm/kasan/report.c:351 [inline]
 kasan_report mm/kasan/report.c:409 [inline]
 kasan_report.cold+0xa9/0x2ae mm/kasan/report.c:393
 ex_handler_refcount+0x164/0x1a0 arch/x86/mm/extable.c:49
 fixup_exception+0x8a/0xc3 arch/x86/mm/extable.c:197
 do_trap_no_signal arch/x86/kernel/traps.c:208 [inline]
 do_trap+0x72/0x230 arch/x86/kernel/traps.c:257
 do_error_trap+0x132/0x2d0 arch/x86/kernel/traps.c:301
 invalid_op+0x1b/0x40 arch/x86/entry/entry_64.S:963
RIP: 0010:inat_get_avx_attribute+0x691f/0x7956
RSP: 0018:ffff888056927b88 EFLAGS: 00010282
RAX: dffffc0000000000 RBX: ffff8880a1129578 RCX: ffff888095cabf80
RDX: dffffc0000000000 RSI: 1ffff1100ad24f62 RDI: ffff888094ac0bfc
RBP: ffff888095cabfc0 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff888095cabf80
R13: ffff888095cabf88 R14: 0000000000000000 R15: ffff8880a1129500
 tipc_receive_from_sock+0x26a/0x460 net/tipc/server.c:273
 tipc_recv_work+0x79/0xf0 net/tipc/server.c:547
 process_one_work+0x813/0x1540 kernel/workqueue.c:2116
 worker_thread+0x5d1/0x1070 kernel/workqueue.c:2250
 kthread+0x30d/0x420 kernel/kthread.c:232
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404

Allocated by task 218:
 save_stack+0x32/0xa0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_kmalloc mm/kasan/kasan.c:551 [inline]
 kasan_kmalloc+0xbf/0xe0 mm/kasan/kasan.c:529
 kmem_cache_alloc_trace+0x14d/0x7b0 mm/slab.c:3618
 kmalloc include/linux/slab.h:488 [inline]
 kzalloc include/linux/slab.h:661 [inline]
 tipc_subscrb_create net/tipc/subscr.c:223 [inline]
 tipc_subscrb_connect_cb+0x40/0x150 net/tipc/subscr.c:344
 tipc_accept_from_sock+0x25b/0x410 net/tipc/server.c:313
 tipc_recv_work+0x79/0xf0 net/tipc/server.c:547
 process_one_work+0x813/0x1540 kernel/workqueue.c:2116
 worker_thread+0x5d1/0x1070 kernel/workqueue.c:2250
 kthread+0x30d/0x420 kernel/kthread.c:232
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404

Freed by task 5:
 save_stack+0x32/0xa0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_slab_free+0x75/0xc0 mm/kasan/kasan.c:524
 __cache_free mm/slab.c:3496 [inline]
 kfree+0xcb/0x260 mm/slab.c:3815
 tipc_subscrb_kref_release net/tipc/subscr.c:155 [inline]
 kref_put include/linux/kref.h:70 [inline]
 tipc_subscrb_put net/tipc/subscr.c:160 [inline]
 tipc_subscrb_delete net/tipc/subscr.c:239 [inline]
 tipc_subscrb_release_cb+0x2c/0x40 net/tipc/subscr.c:316
 tipc_close_conn+0x169/0x210 net/tipc/server.c:203
 tipc_send_to_sock net/tipc/server.c:538 [inline]
 tipc_send_work+0x434/0x540 net/tipc/server.c:564
 process_one_work+0x813/0x1540 kernel/workqueue.c:2116
 worker_thread+0x5d1/0x1070 kernel/workqueue.c:2250
 kthread+0x30d/0x420 kernel/kthread.c:232
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404

The buggy address belongs to the object at ffff888095cabf80
 which belongs to the cache kmalloc-96 of size 96
The buggy address is located 0 bytes inside of
 96-byte region [ffff888095cabf80, ffff888095cabfe0)
The buggy address belongs to the page:
page:ffffea0002572ac0 count:1 mapcount:0 mapping:ffff888095cab000 index:0x0
flags: 0xfffe0000000100(slab)
raw: 00fffe0000000100 ffff888095cab000 0000000000000000 0000000100000020
raw: ffffea00023df620 ffffea0002622c60 ffff88812fe564c0 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff888095cabe80: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc
 ffff888095cabf00: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc
>ffff888095cabf80: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
                   ^
 ffff888095cac000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff888095cac080: 00 00 00 00 fc fc fc fc fc fc fc fc 00 00 00 00
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