[moderation] [mm?] KCSAN: data-race in __anon_vma_prepare / handle_mm_fault (5)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 8ffd015db85f Linux 6.15-rc2
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=17ec7c04580000
kernel config: https://syzkaller.appspot.com/x/.config?x=f723126dfc2a8a53
dashboard link: https://syzkaller.appspot.com/bug?extid=0feecc6cd22af2f3b54d
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
CC: [ak...@linux-foundation.org linux-...@vger.kernel.org linu...@kvack.org]

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/913870d2b804/disk-8ffd015d.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/ccfc14b57099/vmlinux-8ffd015d.xz
kernel image: https://storage.googleapis.com/syzbot-assets/61a5e4adfd43/bzImage-8ffd015d.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+0feecc...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in __anon_vma_prepare / handle_mm_fault

write to 0xffff88810a43e280 of 8 bytes by task 10576 on cpu 1:
__anon_vma_prepare+0x180/0x310 mm/rmap.c:213
__vmf_anon_prepare mm/memory.c:3432 [inline]
vmf_anon_prepare mm/internal.h:415 [inline]
do_anonymous_page mm/memory.c:4996 [inline]
do_pte_missing mm/memory.c:4158 [inline]
handle_pte_fault mm/memory.c:5997 [inline]
__handle_mm_fault mm/memory.c:6140 [inline]
handle_mm_fault+0x1e95/0x2e80 mm/memory.c:6309
do_user_addr_fault arch/x86/mm/fault.c:1337 [inline]
handle_page_fault arch/x86/mm/fault.c:1480 [inline]
exc_page_fault+0x3b9/0x6a0 arch/x86/mm/fault.c:1538
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623

read to 0xffff88810a43e280 of 8 bytes by task 10577 on cpu 0:
__vmf_anon_prepare mm/memory.c:3426 [inline]
vmf_anon_prepare mm/internal.h:415 [inline]
do_anonymous_page mm/memory.c:4996 [inline]
do_pte_missing mm/memory.c:4158 [inline]
handle_pte_fault mm/memory.c:5997 [inline]
__handle_mm_fault mm/memory.c:6140 [inline]
handle_mm_fault+0xda6/0x2e80 mm/memory.c:6309
do_user_addr_fault arch/x86/mm/fault.c:1388 [inline]
handle_page_fault arch/x86/mm/fault.c:1480 [inline]
exc_page_fault+0x296/0x6a0 arch/x86/mm/fault.c:1538
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
__put_user_4+0xd/0x20 arch/x86/lib/putuser.S:92
__sys_socketpair+0xc5/0x440 net/socket.c:1733
__do_sys_socketpair net/socket.c:1799 [inline]
__se_sys_socketpair net/socket.c:1796 [inline]
__x64_sys_socketpair+0x52/0x60 net/socket.c:1796
x64_sys_call+0x2230/0x2e10 arch/x86/include/generated/asm/syscalls_64.h:54
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xc9/0x1c0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x0000000000000000 -> 0xffff888119915d00

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 10577 Comm: syz.3.2302 Not tainted 6.15.0-rc2-syzkaller #0 PREEMPT(voluntary)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
==================================================================


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