syzbot

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BUG: KCSAN: data-race in mas_state_walk / mas_wmb_replace

write to 0xffff888104480900 of 8 bytes by task 8284 on cpu 0:
 mte_set_node_dead lib/maple_tree.c:334 [inline]
 mas_put_in_tree lib/maple_tree.c:1565 [inline]
 mas_topiary_replace lib/maple_tree.c:2341 [inline]
 mas_wmb_replace+0x208/0xfa0 lib/maple_tree.c:2433
 mas_split lib/maple_tree.c:3052 [inline]
 mas_commit_b_node lib/maple_tree.c:3072 [inline]
 mas_wr_bnode lib/maple_tree.c:3739 [inline]
 mas_wr_store_entry+0x13e3/0x2750 lib/maple_tree.c:3771
 mas_store_prealloc+0x760/0xa90 lib/maple_tree.c:5169
 vma_iter_store_overwrite mm/vma.h:541 [inline]
 vma_iter_store_new+0x1c5/0x200 mm/vma.h:548
 vma_complete+0x125/0x580 mm/vma.c:348
 __split_vma+0x5e3/0x660 mm/vma.c:561
 split_vma mm/vma.c:591 [inline]
 vma_modify+0xbee/0xd50 mm/vma.c:1634
 vma_modify_flags+0x10c/0x190 mm/vma.c:1654
 mprotect_fixup+0x30f/0x5e0 mm/mprotect.c:756
 do_mprotect_pkey+0x6d6/0x980 mm/mprotect.c:930
 __do_sys_mprotect mm/mprotect.c:951 [inline]
 __se_sys_mprotect mm/mprotect.c:948 [inline]
 __x64_sys_mprotect+0x48/0x60 mm/mprotect.c:948
 x64_sys_call+0x2c3b/0x3000 arch/x86/include/generated/asm/syscalls_64.h:11
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd8/0x2a0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888104480900 of 8 bytes by task 8285 on cpu 1:
 ma_dead_node lib/maple_tree.c:572 [inline]
 mtree_range_walk lib/maple_tree.c:2580 [inline]
 mas_state_walk+0x485/0x650 lib/maple_tree.c:3298
 mas_walk+0x60/0x150 lib/maple_tree.c:4599
 lock_vma_under_rcu+0x95/0x1b0 mm/mmap_lock.c:253
 do_user_addr_fault+0x233/0x1080 arch/x86/mm/fault.c:1327
 handle_page_fault arch/x86/mm/fault.c:1476 [inline]
 exc_page_fault+0x62/0xa0 arch/x86/mm/fault.c:1532
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618

value changed: 0xffff88810005bd01 -> 0xffff888104480900

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 8285 Comm: syz.1.1716 Tainted: G        W           syzkaller #0 PREEMPT(voluntary) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
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