==================================================================
BUG: KCSAN: data-race in __zone_watermark_ok / get_page_from_freelist

read to 0xffff88812fffce88 of 8 bytes by task 7244 on cpu 0:
 __zone_watermark_ok+0x106/0x240 mm/page_alloc.c:3444
 zone_watermark_fast mm/page_alloc.c:3494 [inline]
 get_page_from_freelist+0x629/0x2300 mm/page_alloc.c:3635
 __alloc_pages_nodemask+0x255/0x4d0 mm/page_alloc.c:4714
 __alloc_pages include/linux/gfp.h:473 [inline]
 __alloc_pages_node include/linux/gfp.h:486 [inline]
 kmem_getpages mm/slab.c:1366 [inline]
 cache_grow_begin+0x76/0x670 mm/slab.c:2599
 cache_alloc_refill mm/slab.c:2971 [inline]
 ____cache_alloc mm/slab.c:3054 [inline]
 ____cache_alloc mm/slab.c:3037 [inline]
 __do_cache_alloc mm/slab.c:3276 [inline]
 slab_alloc mm/slab.c:3311 [inline]
 kmem_cache_alloc_trace+0x4f7/0x5d0 mm/slab.c:3548
 kmalloc include/linux/slab.h:552 [inline]
 kzalloc include/linux/slab.h:748 [inline]
 ipv4_sysctl_init_net+0x108/0x220 net/ipv4/sysctl_net_ipv4.c:1341
 ops_init+0x8c/0x240 net/core/net_namespace.c:137
 setup_net+0x194/0x4b0 net/core/net_namespace.c:334
 copy_net_ns+0x1dc/0x336 net/core/net_namespace.c:475
 create_new_namespaces+0x2e2/0x4b0 kernel/nsproxy.c:103
 unshare_nsproxy_namespaces+0xb9/0x170 kernel/nsproxy.c:202
 ksys_unshare+0x2dc/0x710 kernel/fork.c:2841
 __do_sys_unshare kernel/fork.c:2909 [inline]
 __se_sys_unshare kernel/fork.c:2907 [inline]
 __x64_sys_unshare+0x28/0x40 kernel/fork.c:2907
 do_syscall_64+0xcf/0x2f0 arch/x86/entry/common.c:296

write to 0xffff88812fffce88 of 8 bytes by task 7220 on cpu 1:
 add_to_free_area include/linux/mmzone.h:108 [inline]
 expand mm/page_alloc.c:2033 [inline]
 __rmqueue_smallest mm/page_alloc.c:2192 [inline]
 __rmqueue mm/page_alloc.c:2711 [inline]
 rmqueue_bulk mm/page_alloc.c:2738 [inline]
 __rmqueue_pcplist mm/page_alloc.c:3209 [inline]
 rmqueue_pcplist mm/page_alloc.c:3237 [inline]
 rmqueue mm/page_alloc.c:3259 [inline]
 get_page_from_freelist+0x131e/0x2300 mm/page_alloc.c:3677
 __alloc_pages_nodemask+0x255/0x4d0 mm/page_alloc.c:4714
 alloc_pages_current+0xd1/0x170 mm/mempolicy.c:2153
 alloc_pages include/linux/gfp.h:509 [inline]
 __page_cache_alloc mm/filemap.c:972 [inline]
 __page_cache_alloc+0x183/0x1a0 mm/filemap.c:957
 __do_page_cache_readahead+0x13e/0x390 mm/readahead.c:196
 ra_submit mm/internal.h:62 [inline]
 ondemand_readahead+0x35d/0x710 mm/readahead.c:492
 page_cache_async_readahead+0x22c/0x250 mm/readahead.c:574
 generic_file_buffered_read mm/filemap.c:2079 [inline]
 generic_file_read_iter+0xffc/0x1440 mm/filemap.c:2344
 ext4_file_read_iter fs/ext4/file.c:77 [inline]
 ext4_file_read_iter+0xfa/0x240 fs/ext4/file.c:65
 call_read_iter include/linux/fs.h:1864 [inline]
 new_sync_read+0x389/0x4f0 fs/read_write.c:414
 __vfs_read+0xb1/0xc0 fs/read_write.c:427
 integrity_kernel_read+0xa1/0xe0 security/integrity/iint.c:200
 ima_calc_file_hash_tfm+0x1b5/0x260 security/integrity/ima/ima_crypto.c:352

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 7220 Comm: syz-fuzzer Not tainted 5.3.0+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================