==================================================================
BUG: KCSAN: data-race in ion_page_pool_free / ion_page_pool_shrink

read to 0xffff888218063184 of 4 bytes by task 1768 on cpu 1:
 ion_page_pool_total drivers/staging/android/ion/ion_page_pool.c:92 [inline]
 ion_page_pool_shrink+0x238/0x250 drivers/staging/android/ion/ion_page_pool.c:112
 ion_system_heap_shrink+0x69/0xe0 drivers/staging/android/ion/ion_system_heap.c:189
 ion_heap_shrink_count+0x83/0xa0 drivers/staging/android/ion/ion_heap.c:273
 do_shrink_slab+0xb7/0x5a0 mm/vmscan.c:444
 shrink_slab mm/vmscan.c:687 [inline]
 shrink_slab+0x147/0x540 mm/vmscan.c:660
 shrink_node_memcgs mm/vmscan.c:2687 [inline]
 shrink_node+0x34a/0xfe0 mm/vmscan.c:2791
 kswapd_shrink_node mm/vmscan.c:3539 [inline]
 balance_pgdat+0x68d/0xda0 mm/vmscan.c:3697
 kswapd+0x35b/0x800 mm/vmscan.c:3948
 kthread+0x1d4/0x200 drivers/block/aoe/aoecmd.c:1253
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352

write to 0xffff888218063184 of 4 bytes by task 3540 on cpu 0:
 ion_page_pool_add drivers/staging/android/ion/ion_page_pool.c:36 [inline]
 ion_page_pool_free+0x117/0x200 drivers/staging/android/ion/ion_page_pool.c:87
 free_buffer_page.isra.0+0x112/0x160 drivers/staging/android/ion/ion_system_heap.c:70
 ion_system_heap_free+0xc9/0x130 drivers/staging/android/ion/ion_system_heap.c:166
 ion_buffer_destroy+0xcb/0x1a0 drivers/staging/android/ion/ion.c:93
 ion_heap_deferred_free+0x1cf/0x330 drivers/staging/android/ion/ion_heap.c:239
 kthread+0x1d4/0x200 drivers/block/aoe/aoecmd.c:1253
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 3540 Comm: ion_system_heap Not tainted 5.5.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================