syzbot

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BUG: KCSAN: data-race in call_rcu / mas_state_walk

write to 0xffff888103e94908 of 8 bytes by task 5036 on cpu 0:
 __call_rcu_common kernel/rcu/tree.c:3122 [inline]
 call_rcu+0x51/0x3f0 kernel/rcu/tree.c:3243
 ma_free_rcu lib/maple_tree.c:211 [inline]
 mas_topiary_node lib/maple_tree.c:2527 [inline]
 mas_topiary_replace lib/maple_tree.c:2628 [inline]
 mas_wmb_replace+0xc6a/0x14a0 lib/maple_tree.c:2651
 mas_split lib/maple_tree.c:3390 [inline]
 mas_commit_b_node lib/maple_tree.c:3410 [inline]
 mas_wr_bnode lib/maple_tree.c:4079 [inline]
 mas_wr_store_entry+0x1773/0x2b50 lib/maple_tree.c:4111
 mas_store_prealloc+0x74d/0x9e0 lib/maple_tree.c:5510
 vma_iter_store_overwrite mm/vma.h:501 [inline]
 vma_iter_store_new+0x1c5/0x200 mm/vma.h:508
 vma_complete+0x125/0x580 mm/vma.c:354
 __split_vma+0x591/0x650 mm/vma.c:568
 split_vma mm/vma.c:598 [inline]
 vma_modify+0x21e/0xc80 mm/vma.c:1623
 vma_modify_flags+0x101/0x130 mm/vma.c:1649
 mprotect_fixup+0x2cc/0x570 mm/mprotect.c:819
 do_mprotect_pkey+0x6d6/0x980 mm/mprotect.c:993
 __do_sys_mprotect mm/mprotect.c:1014 [inline]
 __se_sys_mprotect mm/mprotect.c:1011 [inline]
 __x64_sys_mprotect+0x48/0x60 mm/mprotect.c:1011
 x64_sys_call+0x274e/0x2ff0 arch/x86/include/generated/asm/syscalls_64.h:11
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888103e94908 of 8 bytes by task 5038 on cpu 1:
 mtree_range_walk lib/maple_tree.c:2779 [inline]
 mas_state_walk+0x28f/0x650 lib/maple_tree.c:3636
 mas_walk+0x60/0x150 lib/maple_tree.c:4939
 lock_vma_under_rcu+0xa2/0x2f0 mm/mmap_lock.c:143
 do_user_addr_fault+0x233/0x1090 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:623

value changed: 0x0000555562951fff -> 0xffff888103e94808

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 5038 Comm: syz.1.369 Not tainted 6.16.0-syzkaller-10355-gf2d282e1dfb3 #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
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