[moderation] [mm?] KCSAN: data-race in mas_replace_node / mas_state_walk (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: ca91b9500108 Merge tag 'v6.15-rc4-ksmbd-server-fixes' of g..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=17c53374580000
kernel config: https://syzkaller.appspot.com/x/.config?x=6bd11c5d4ce102b4
dashboard link: https://syzkaller.appspot.com/bug?extid=b737e61fbcac97053f96
compiler: Debian clang version 20.1.2 (++20250402124445+58df0ef89dd6-1~exp1~20250402004600.97), Debian LLD 20.1.2
CC: [Liam.H...@oracle.com ak...@linux-foundation.org ja...@google.com linux-...@vger.kernel.org linu...@kvack.org lorenzo...@oracle.com pfal...@suse.de vba...@suse.cz]

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/0878b9ddf677/disk-ca91b950.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/0bcf0e9b4f36/vmlinux-ca91b950.xz
kernel image: https://storage.googleapis.com/syzbot-assets/fcc675eb017a/bzImage-ca91b950.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+b737e6...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in mas_replace_node / mas_state_walk

write to 0xffff88810337ea00 of 8 bytes by task 16052 on cpu 1:
mte_set_node_dead lib/maple_tree.c:337 [inline]
mas_put_in_tree lib/maple_tree.c:1735 [inline]
mas_replace_node+0x1c9/0x440 lib/maple_tree.c:1749
mas_wr_node_store lib/maple_tree.c:3863 [inline]
mas_wr_store_entry+0x2425/0x2b60 lib/maple_tree.c:4083
mas_store_prealloc+0x74d/0x9e0 lib/maple_tree.c:5475
vma_iter_store_overwrite mm/vma.h:448 [inline]
vma_iter_store_new+0x1c5/0x200 mm/vma.h:455
vma_complete+0x125/0x570 mm/vma.c:323
__split_vma+0x54c/0x610 mm/vma.c:523
split_vma mm/vma.c:553 [inline]
vma_modify+0x107/0x210 mm/vma.c:1579
vma_modify_flags+0x101/0x130 mm/vma.c:1605
mprotect_fixup+0x2cc/0x570 mm/mprotect.c:658
do_mprotect_pkey+0x6d6/0x980 mm/mprotect.c:832
__do_sys_mprotect mm/mprotect.c:853 [inline]
__se_sys_mprotect mm/mprotect.c:850 [inline]
__x64_sys_mprotect+0x48/0x60 mm/mprotect.c:850
x64_sys_call+0x2794/0x2fb0 arch/x86/include/generated/asm/syscalls_64.h:11
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xd0/0x1a0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff88810337ea00 of 8 bytes by task 16054 on cpu 0:
ma_dead_node lib/maple_tree.c:575 [inline]
mtree_range_walk lib/maple_tree.c:2788 [inline]
mas_state_walk+0x485/0x650 lib/maple_tree.c:3605
mas_walk+0x30/0x120 lib/maple_tree.c:4905
lock_vma_under_rcu+0xa2/0x2f0 mm/memory.c:6553
do_user_addr_fault+0x233/0x1090 arch/x86/mm/fault.c:1328
handle_page_fault arch/x86/mm/fault.c:1480 [inline]
exc_page_fault+0x54/0xc0 arch/x86/mm/fault.c:1538
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623

value changed: 0xffff8881036fa60e -> 0xffff88810337ea00

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 16054 Comm: syz.5.4805 Not tainted 6.15.0-rc4-syzkaller-00021-gca91b9500108 #0 PREEMPT(voluntary)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025
==================================================================


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.