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

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 02ddfb981de8 Merge tag 'scsi-fixes' of git://git.kernel.or..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=12f23574580000
kernel config: https://syzkaller.appspot.com/x/.config?x=881e3ae9e3cc6f4e
dashboard link: https://syzkaller.appspot.com/bug?extid=c340ed86ab0dac6ba5a7
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/2bee38e5cde1/disk-02ddfb98.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/4f48b9d54eac/vmlinux-02ddfb98.xz
kernel image: https://storage.googleapis.com/syzbot-assets/195c60d459be/bzImage-02ddfb98.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+c340ed...@syzkaller.appspotmail.com

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

write to 0xffff888104554808 of 8 bytes by task 8820 on cpu 0:
__call_rcu_common kernel/rcu/tree.c:3081 [inline]
call_rcu+0x48/0x3e0 kernel/rcu/tree.c:3202
ma_free_rcu lib/maple_tree.c:211 [inline]
mas_topiary_node lib/maple_tree.c:2519 [inline]
mas_topiary_replace lib/maple_tree.c:2625 [inline]
mas_wmb_replace+0xf7b/0x14a0 lib/maple_tree.c:2641
mas_split lib/maple_tree.c:3368 [inline]
mas_commit_b_node lib/maple_tree.c:3388 [inline]
mas_wr_bnode lib/maple_tree.c:4049 [inline]
mas_wr_store_entry+0x17ae/0x2b60 lib/maple_tree.c:4090
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 0xffff888104554808 of 8 bytes by task 8822 on cpu 1:
mtree_range_walk lib/maple_tree.c:2769 [inline]
mas_state_walk+0x28f/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: 0x0000555575a12fff -> 0xffff8881045d3108

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 8822 Comm: syz.1.1861 Not tainted 6.15.0-rc3-syzkaller-00094-g02ddfb981de8 #0 PREEMPT(voluntary)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
==================================================================


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[syzbot]

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