syzbot

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BUG: KCSAN: data-race in mas_state_walk / mast_fill_bnode

write to 0xffff8881047a6908 of 8 bytes by task 8383 on cpu 0:
 mat_add lib/maple_tree.c:995 [inline]
 mast_fill_bnode+0x132/0xeb0 lib/maple_tree.c:3373
 mas_split lib/maple_tree.c:3579 [inline]
 mas_commit_b_node lib/maple_tree.c:3638 [inline]
 mas_wr_bnode lib/maple_tree.c:4323 [inline]
 mas_wr_modify+0x14af/0x35e0 lib/maple_tree.c:4361
 mas_wr_store_entry+0x668/0x810 lib/maple_tree.c:4398
 mas_store_prealloc+0xe9/0x250 lib/maple_tree.c:5537
 vma_iter_store+0xcb/0xe0 mm/internal.h:1090
 mmap_region+0xe6c/0x14d0 mm/mmap.c:2818
 do_mmap+0x69c/0xaa0 mm/mmap.c:1363
 vm_mmap_pgoff+0x12f/0x240 mm/util.c:543
 ksys_mmap_pgoff+0xc5/0x330 mm/mmap.c:1409
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

read to 0xffff8881047a6908 of 8 bytes by task 8390 on cpu 1:
 mtree_range_walk lib/maple_tree.c:2957 [inline]
 mas_state_walk+0x28b/0x5d0 lib/maple_tree.c:3869
 mas_walk+0x7e/0x160 lib/maple_tree.c:4988
 lock_vma_under_rcu+0x8d/0x2d0 mm/memory.c:5385
 do_user_addr_fault arch/x86/mm/fault.c:1335 [inline]
 handle_page_fault arch/x86/mm/fault.c:1486 [inline]
 exc_page_fault+0x160/0x650 arch/x86/mm/fault.c:1542
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:570

value changed: 0x000000001fffefff -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 8390 Comm: syz-executor.2 Tainted: G        W          6.5.0-syzkaller-01810-gf97e18a3f2fb #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023
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