From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj1-f70.google.com (mail-pj1-f70.google.com [209.85.216.70]) (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 F3A7832B114 for ; Tue, 1 Sep 2026 03:04:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.70 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788231865; cv=none; b=H3BE9zlvRMdhgstzs2M4rJ2pIafa2J5A6eqxtGECu2qvZ0tWaV08w9MFQ+Ecv+CtR8hDNdeY02jH7dtosw0wkxRfd/rtu3xjmPApiQzr4v1P/KKPOn4sRWuO9XSWm4dwGYoEDNsJYq4cqKUVur1W01w0NZ8Thh8posWguBEQxrc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788231865; c=relaxed/simple; bh=alwkBD/+SQUXc6OQqN4BOwQT8uua2JgeRzRa5U2y8kY=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=O0WZ7HVmgFNW/MqMOQHVBfPLUMVMGSMvyWk8Zbx+fx/2c0xj9s1lGli1t3c7ookHv19RI7kJOJgygZp1hGW+3eiqJqJGGkGKuN80AYVIUpgryXRg3mwIyykXdUTI45MIEwWcvfEP6zWwFRQOFe27sOvp/WU/CHjv+cANxprozhg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--cmllamas.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=q4h0KaET; arc=none smtp.client-ip=209.85.216.70 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--cmllamas.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="q4h0KaET" Received: by mail-pj1-f70.google.com with SMTP id 98e67ed59e1d1-3965ba1ba3eso5620163a91.2 for ; Mon, 31 Aug 2026 20:04:23 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1788231863; x=1788836663; darn=vger.kernel.org; h=content-type:cc:to:from:subject:message-id:references:mime-version :in-reply-to:date:from:to:cc:subject:date:message-id:reply-to :content-type; bh=N3TdueNSyiGTL64eGdavHuKzRARmETdxICv7py0WGZo=; b=q4h0KaETtAlhpO/xAM8S7pXm4VcQ7A15cxx2FQOcVenHS0FuKYLfvCtA1tQ6P3QHwa 54rP5j4npT5LYQpgmCNGdL4DWIQcOCW+hboOHmcGg4aXEVPJgK6KnA18Yfqf2II2+JEz 6NdPZqj9bU/fndX53t8JHGM9cmBxhzXdcHQB2y79UTmD7i0Nzouxp5xyA9HnWqgDV1bn eSqMI/HHxrM+iKqe9+hSaqglYnsRSjhxx/rg70AA25abWVJi2wB2WuBm43koYuZRpTHz HjGJV36pBePE20kAjNEmsUS9ZDgAkQYBklWH0ZjOPYyx8RzUDh9OHV9g573LkVRHOKbH CU/w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1788231863; x=1788836663; h=content-type:cc:to:from:subject:message-id:references:mime-version :in-reply-to:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to:content-type; bh=N3TdueNSyiGTL64eGdavHuKzRARmETdxICv7py0WGZo=; b=r3L4ng6vVQLbXyVKH0Qn6be3z/8mszzEi8InUMfl/VfPeBHRcdxjvpYrt6bbW5WcxN VAsR1xz7/YX5e8XqoDLkDHC04dTnYTsZCsM4700jBLe4OaWKI8feCoM1pIaJ3OEiSFoQ bQGAaw2f8Y8HmvEIPzCPLc2tjIxT0tAY5E4usb78kBQ+iABTivbDQVIdV11lyYXpHf2m Chrn2okUL4VztcM4Rzy/YOdPSgGBmn51dYCDKEFH7aEQ0CsDkqngIoAjarwQIbzpF9vA xXftKdrBKyQu7xisbgV3aJQzNeSD/uO9fwSBXfYunBs3PfRgsLL+eJXcc2Nkk2kFqHXU s22A== X-Forwarded-Encrypted: i=1; AKwUvByFMxp6xkKULjHonPt7F6Cee4h1mI3R4qUeMPWj6kAfaKO8WEMZV1N4Oa4RX0DvYemNGVy5hgWDhCV2BZQ=@vger.kernel.org X-Gm-Message-State: AFuF++kiKooywjNzf4oLTvW7zcGqPGujFiDvgSsAuYl2OfU9/Yjrda8i Q46vG5Up4O49teBQSXfxLX0YPPswhBWWSYWEdD0UYL7gnY4u0eEnN0OVwhnb69hgkDDD4Wxf4qK fbaEdkRNdvCfy+w== X-Received: from dyx8.prod.google.com ([2002:a05:693c:8208:b0:32d:dd4b:f2b8]) (user=cmllamas job=prod-delivery.src-stubby-dispatcher) by 2002:a17:90b:54d0:b0:398:d93a:b343 with SMTP id 98e67ed59e1d1-39907ab0ec5mr7583812a91.3.1788231863112; Mon, 31 Aug 2026 20:04:23 -0700 (PDT) Date: Tue, 1 Sep 2026 03:04:12 +0000 In-Reply-To: <20260901030419.470246-1-cmllamas@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260901030419.470246-1-cmllamas@google.com> X-Mailer: git-send-email 2.55.0.897.gb25b4bd76c-goog Message-ID: <20260901030419.470246-2-cmllamas@google.com> Subject: [PATCH v2 1/5] binder: set VM_DONTEXPAND From: Carlos Llamas To: Greg Kroah-Hartman , "=?UTF-8?q?Arve=20Hj=C3=B8nnev=C3=A5g?=" , Todd Kjos , Christian Brauner , Carlos Llamas , Alice Ryhl Cc: kernel-team@android.com, linux-kernel@vger.kernel.org, Suren Baghdasaryan , stable@vger.kernel.org, Sashiko Content-Type: text/plain; charset="UTF-8" Binder does not support expanding VMAs. It caches the original size under alloc->buffer_size during mmap() and expanding the VMA would only result in a wasted virtual range. Set the VM_DONTEXPAND flag to prevent the vma from being expanded via mremap(). Cc: stable@vger.kernel.org Fixes: 457b9a6f09f0 ("Staging: android: add binder driver") Reported-by: Sashiko Closes: https://sashiko.dev/#/patchset/20260831224145.169403-1-cmllamas%40google.com?part=1 Signed-off-by: Carlos Llamas --- drivers/android/binder.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/android/binder.c b/drivers/android/binder.c index 8f2ef1bd539f..1b492ed48ea6 100644 --- a/drivers/android/binder.c +++ b/drivers/android/binder.c @@ -6056,7 +6056,8 @@ static int binder_mmap(struct file *filp, struct vm_area_struct *vma) proc->pid, vma->vm_start, vma->vm_end, "bad vm_flags", -EPERM); return -EPERM; } - vm_flags_mod(vma, VM_DONTCOPY | VM_MIXEDMAP, VM_MAYWRITE); + vm_flags_mod(vma, VM_DONTCOPY | VM_MIXEDMAP | VM_DONTEXPAND, + VM_MAYWRITE); vma->vm_ops = &binder_vm_ops; vma->vm_private_data = proc; -- 2.55.0.897.gb25b4bd76c-goog