From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oi1-f207.google.com (mail-oi1-f207.google.com [209.85.167.207]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A5DB8395265 for ; Wed, 14 Jan 2026 16:32:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.167.207 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768408346; cv=none; b=upsKP+FQ+lbV9seh8ErT9J+H+a6Hd8WpZtlrrjzOFP+BoVJ1qGy24cC84TTgNIqTIgAUW9gICDAw9AJnfCpQZItrJJDGQPEcsHgkLVfdwqaNpnkthFmBlkxWWEFXOwlRMbJWEFZZmnYzNZoD4VvkQdkqmbxMpUT9bpLo28Tw2mg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768408346; c=relaxed/simple; bh=5eTR2qXdGy9UOrC7AsB+IU9KQ+KgVDj2JskkGHCN9hE=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=PuWpxKHQeyLSvgBbl13MP2zGSxE14JIcYgvCIC2QjaGb3rteRGAxQWOkXKCKfmj33y/8PCe/sEoJZW649BWJqkzQhIbaA5Ex66uFbNHgTTknvCKIL2mYlK2bAf0B9u7DwHlGN5muKQ+cXSD6eQupKaaxZNnEygVHg6Go3ArsJwI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com; arc=none smtp.client-ip=209.85.167.207 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com Received: by mail-oi1-f207.google.com with SMTP id 5614622812f47-450d5d26c0fso18730963b6e.3 for ; Wed, 14 Jan 2026 08:32:24 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1768408343; x=1769013143; h=to:from:subject:message-id:date:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=3NDxiqbP2esx68zAkMDEgHgnGAOZ5U1LmYaSTqlT+gs=; b=GopqSBTNTdKEGYfVj28hyUnKqNsRY5yK/kT3MNqF2aJvnodi91xwhS9/bbyLsq5rTP qQ77+m74rYibIxH+GaIt+MXYs2elt3CVN6U4KkCZoT150bWIcJSWJwoQ5PAwz+ilnLBI 5wTXss6aF3vKqRf6/P1YDElMWfGPoY76kKPwSznVfzIF3YP3zax6V3WxDz0Mlsa0R0k1 tE8Tz1kTjdAThfrqjMs1QjWwYfDfr+T5xEaqEW+942us+49XU9rer4nQy+B7y9/86N+K 4ajr3EGKodTA0NgNjJObZXUfDkSO5rMU9UhcXxaTFRQjbsQcius72b3JQjRNeFiqw0hB tHTw== X-Forwarded-Encrypted: i=1; AJvYcCX8t1UdErbDg7mf9FRQOP+x/SMbtNS43AitvG5jK7fLEUAudXQ3JnkhW5vA/RWvlurxGm8fMsicrbjgvko=@vger.kernel.org X-Gm-Message-State: AOJu0Yy7/qEqAIqMDE4yEqKO12MILhngjdi9dyrFH1hDrn5KEkvoDVP8 WqqmQKJb06wUi3w4tgiNAD6u44/3lvma4y54aJRzf7hP0+PHPFvo0FgA9XoL4ZUC5Gv66yDm9UP HXeCIOIUJDUP3avUSBPGI/WKNFyT+Ahvx0bbI/3O7YawbQzIIr88tnWo9Bx4= Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6820:8312:b0:65b:3376:a8a7 with SMTP id 006d021491bc7-66100739b62mr1429416eaf.80.1768408343549; Wed, 14 Jan 2026 08:32:23 -0800 (PST) Date: Wed, 14 Jan 2026 08:32:23 -0800 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6967c517.050a0220.150504.0007.GAE@google.com> Subject: [syzbot] [mm?] KCSAN: data-race in __anon_vma_prepare / __vmf_anon_prepare From: syzbot To: Liam.Howlett@oracle.com, akpm@linux-foundation.org, david@kernel.org, harry.yoo@oracle.com, jannh@google.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, lorenzo.stoakes@oracle.com, riel@surriel.com, syzkaller-bugs@googlegroups.com, vbabka@suse.cz Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: cfd4039213e7 Merge tag 'io_uring-6.19-20251208' of git://g.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=1554d992580000 kernel config: https://syzkaller.appspot.com/x/.config?x=c3201432211be40f dashboard link: https://syzkaller.appspot.com/bug?extid=f5d897f5194d92aa1769 compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/9f556ae6e3c4/disk-cfd40392.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/efcf53c1d459/vmlinux-cfd40392.xz kernel image: https://storage.googleapis.com/syzbot-assets/858f42961336/bzImage-cfd40392.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+f5d897f5194d92aa1769@syzkaller.appspotmail.com ================================================================== BUG: KCSAN: data-race in __anon_vma_prepare / __vmf_anon_prepare write to 0xffff88811c751e80 of 8 bytes by task 13471 on cpu 1: __anon_vma_prepare+0x172/0x2f0 mm/rmap.c:212 __vmf_anon_prepare+0x91/0x100 mm/memory.c:3673 hugetlb_no_page+0x1c4/0x10d0 mm/hugetlb.c:5782 hugetlb_fault+0x4cf/0xce0 mm/hugetlb.c:-1 handle_mm_fault+0x1894/0x2c60 mm/memory.c:6578 do_user_addr_fault+0x3fe/0x1080 arch/x86/mm/fault.c:1387 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 fault_in_readable+0xad/0x170 mm/gup.c:-1 fault_in_iov_iter_readable+0x129/0x210 lib/iov_iter.c:106 generic_perform_write+0x3cf/0x490 mm/filemap.c:4363 shmem_file_write_iter+0xc5/0xf0 mm/shmem.c:3490 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x52a/0x960 fs/read_write.c:686 ksys_pwrite64 fs/read_write.c:793 [inline] __do_sys_pwrite64 fs/read_write.c:801 [inline] __se_sys_pwrite64 fs/read_write.c:798 [inline] __x64_sys_pwrite64+0xfd/0x150 fs/read_write.c:798 x64_sys_call+0x9f7/0x3000 arch/x86/include/generated/asm/syscalls_64.h:19 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 0xffff88811c751e80 of 8 bytes by task 13473 on cpu 0: __vmf_anon_prepare+0x26/0x100 mm/memory.c:3667 hugetlb_no_page+0x1c4/0x10d0 mm/hugetlb.c:5782 hugetlb_fault+0x4cf/0xce0 mm/hugetlb.c:-1 handle_mm_fault+0x1894/0x2c60 mm/memory.c:6578 faultin_page mm/gup.c:1126 [inline] __get_user_pages+0x1024/0x1ed0 mm/gup.c:1428 populate_vma_page_range mm/gup.c:1860 [inline] __mm_populate+0x243/0x3a0 mm/gup.c:1963 mm_populate include/linux/mm.h:3701 [inline] vm_mmap_pgoff+0x232/0x2e0 mm/util.c:586 ksys_mmap_pgoff+0x268/0x310 mm/mmap.c:604 x64_sys_call+0x16bb/0x3000 arch/x86/include/generated/asm/syscalls_64.h:10 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 value changed: 0x0000000000000000 -> 0xffff888104ecca28 Reported by Kernel Concurrency Sanitizer on: CPU: 0 UID: 0 PID: 13473 Comm: syz.2.3219 Tainted: G W syzkaller #0 PREEMPT(voluntary) Tainted: [W]=WARN Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 ================================================================== --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@googlegroups.com. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. If the report is already addressed, let syzbot know by replying with: #syz fix: exact-commit-title If you want to overwrite report's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the report is a duplicate of another one, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup