==================================================================
BUG: KASAN: use-after-free in cmpxchg_size /./include/asm-generic/atomic-instrumented.h:355 [inline]
BUG: KASAN: use-after-free in bpf_tcp_close+0x469/0xb90 /kernel/bpf/sockmap.c:344
Write of size 8 at addr ffff88008948ddc0 by task syz-executor.3/5717

CPU: 1 PID: 5717 Comm: syz-executor.3 Not tainted 4.18.0-rc1+ #1
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+0x109/0x15a /lib/dump_stack.c:113
 print_address_description.cold.8+0x9/0x1ff /mm/kasan/report.c:256
 kasan_report_error /mm/kasan/report.c:354 [inline]
 kasan_report.cold.9+0x242/0x2fe /mm/kasan/report.c:412
 check_memory_region_inline /mm/kasan/kasan.c:260 [inline]
 check_memory_region+0x13e/0x1b0 /mm/kasan/kasan.c:267
 kasan_check_write+0x14/0x20 /mm/kasan/kasan.c:278
 cmpxchg_size /./include/asm-generic/atomic-instrumented.h:355 [inline]
 bpf_tcp_close+0x469/0xb90 /kernel/bpf/sockmap.c:344
 inet_release+0xd9/0x1c0 /net/ipv4/af_inet.c:427
 inet6_release+0x46/0x60 /net/ipv6/af_inet6.c:459
 __sock_release+0xc2/0x230 /net/socket.c:603
 sock_close+0x10/0x20 /net/socket.c:1186
 __fput+0x238/0x780 /fs/file_table.c:209
 ____fput+0x9/0x10 /fs/file_table.c:243
 task_work_run+0x111/0x180 /kernel/task_work.c:113
 tracehook_notify_resume /./include/linux/tracehook.h:192 [inline]
 exit_to_usermode_loop+0x1a2/0x200 /arch/x86/entry/common.c:166
 prepare_exit_to_usermode /arch/x86/entry/common.c:197 [inline]
 syscall_return_slowpath /arch/x86/entry/common.c:268 [inline]
 do_syscall_64+0x407/0x4d0 /arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x413501
Code: 75 14 b8 03 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 04 1b 00 00 c3 48 83 ec 08 e8 0a fc ff ff 48 89 04 24 b8 03 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 53 fc ff ff 48 89 d0 48 83 c4 08 48 3d 01 
RSP: 002b:00007ffe77eaa5f0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000006 RCX: 0000000000413501
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000005
RBP: 0000000000000001 R08: ffffffffffffffff R09: ffffffffffffffff
R10: 00007ffe77eaa6d0 R11: 0000000000000293 R12: 000000000075bf20
R13: 000000000002c130 R14: 0000000000761178 R15: ffffffffffffffff

Allocated by task 5723:
 save_stack+0x43/0xd0 /mm/kasan/kasan.c:448
 set_track /mm/kasan/kasan.c:460 [inline]
 kasan_kmalloc+0xc7/0xe0 /mm/kasan/kasan.c:553
 __do_kmalloc_node /mm/slab.c:3682 [inline]
 __kmalloc_node+0x47/0x70 /mm/slab.c:3689
 kmalloc_node /./include/linux/slab.h:555 [inline]
 bpf_map_area_alloc+0x22/0x50 /kernel/bpf/syscall.c:147
 sock_map_alloc+0x2b4/0x350 /kernel/bpf/sockmap.c:1653
 find_and_alloc_map /kernel/bpf/syscall.c:129 [inline]
 map_create+0x230/0xc40 /kernel/bpf/syscall.c:453
 __do_sys_bpf /kernel/bpf/syscall.c:2290 [inline]
 __se_sys_bpf /kernel/bpf/syscall.c:2267 [inline]
 __x64_sys_bpf+0x1d1/0x380 /kernel/bpf/syscall.c:2267
 do_syscall_64+0xd0/0x4d0 /arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 8528:
 save_stack+0x43/0xd0 /mm/kasan/kasan.c:448
 set_track /mm/kasan/kasan.c:460 [inline]
 __kasan_slab_free+0x102/0x150 /mm/kasan/kasan.c:521
 kasan_slab_free+0xe/0x10 /mm/kasan/kasan.c:528
 __cache_free /mm/slab.c:3498 [inline]
 kfree+0xcf/0x270 /mm/slab.c:3813
 kvfree+0x2c/0x30 /mm/util.c:442
 bpf_map_area_free+0x9/0x10 /kernel/bpf/syscall.c:158
 sock_map_remove_complete /kernel/bpf/sockmap.c:1540 [inline]
 sock_map_free+0x22e/0x300 /kernel/bpf/sockmap.c:1729
 bpf_map_free_deferred+0xaf/0xe0 /kernel/bpf/syscall.c:262
 process_one_work+0x830/0x1650 /kernel/workqueue.c:2153
 worker_thread+0x85/0xb60 /kernel/workqueue.c:2296
 kthread+0x316/0x3d0 /kernel/kthread.c:240
 ret_from_fork+0x24/0x30 /arch/x86/entry/entry_64.S:412

The buggy address belongs to the object at ffff88008948ddc0
 which belongs to the cache kmalloc-8192 of size 8192
The buggy address is located 0 bytes inside of
 8192-byte region [ffff88008948ddc0, ffff88008948fdc0)
The buggy address belongs to the page:
page:ffffea0002252300 count:1 mapcount:0 mapping:ffff8800aa802080 index:0x0 compound_mapcount: 0
flags: 0x1fffc0000008100(slab|head)
raw: 01fffc0000008100 ffffea0002352d08 ffffea0002123d08 ffff8800aa802080
raw: 0000000000000000 ffff88008948ddc0 0000000100000001 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88008948dc80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88008948dd00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88008948dd80: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
                                           ^
 ffff88008948de00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88008948de80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================