From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pl1-f197.google.com (mail-pl1-f197.google.com [209.85.214.197]) (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 EC57344A3EE for ; Tue, 1 Sep 2026 20:52:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.197 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788295978; cv=none; b=g2I71OzdAhqYEWMCBN5rwBmN1Xmer6AcKh8X54U398kY0IJM/6hfbbkF5FftriC5M1KnjtIJyPEALZ3M1PymHMnW04zRHjOumUbergdHRnGCUaOBqCp0YcS5+lRFp9CegVcSP9XpMdxp34JX1Xe9l64mangHNq3Mgy6udo3z14U= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788295978; c=relaxed/simple; bh=mC01VX1n7muqMaBoWw5J7zX+JcinZQb0IpbAjZAJoWg=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=krn+DNV815pPArPySEdFh7Bw3K1Xzyuc+tAjlEXmKFccBiO7CsEtLt+VJfVFV5IbQkbYjjfAaJEXrnbYh+pbHtWYnp/0nn/XiZQeAHaNxAIzQbMgga2jIpwU8aPGrYJfIlnnVdQG6wZLC2Io9TA2xV3/KzL2s3vcoKH7DJHUKeI= 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=MQzoiVT1; arc=none smtp.client-ip=209.85.214.197 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="MQzoiVT1" Received: by mail-pl1-f197.google.com with SMTP id d9443c01a7336-2ce7dff6253so15698935ad.1 for ; Tue, 01 Sep 2026 13:52:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1788295976; x=1788900776; 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=zocSb9A1qfC5TL5NRNiwUw0+UxJIZxHTRhrF7BbbrB0=; b=MQzoiVT1Y2bEl7t4/tMFXOGz6gcgV9h6I/ENOIWVQy289NffZqaVD3bcSnc7m/PvLH v7EaHE6WGvYhDxZx8pii+XxhOiOeeCSKxjkXvE7DYk40JoQjdrY8S4vauo8V52B3DKkU iMs4QJ8njowrYRwpRNzbPQKHmwFLvPO0XgFQOyWMXsPMF7trE4GzbgD3IxUvECraUHuO 3XCS1jXGjPlX9NBTBYoN6SLlVY/olUA0mS8sxvkYyXU0zTrsjpH1F2/gLRbTELOzHUvS QtzhPaLy5Fv8T8c7kN1LznZAXG6XJA7jgDaoVjwhkQghIF0uVTx/VLs7ymPhSFMyuHGb 5HYA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1788295976; x=1788900776; 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=zocSb9A1qfC5TL5NRNiwUw0+UxJIZxHTRhrF7BbbrB0=; b=du+oo4R6VdePEMrlgyYCmrAX6GqtIAyrqpUiHSpnNSK6f40RL0CK0TDs9+RKcUSDkp MZEOiD0fO8AEHCgUn0dBhc0l6RycZ4J54WAhruUk74RonWHwad4cNbjMtoN/vTguvU96 N1/oQZXBI40DAwtenihQ2gBWCUsFeBzqr4dOCo7X6b22yEEVAHWMraZ4G37nR6UMPhkd BlI+eHHSBrXQKCbHY5T8SD67tp8ImxTkdaQ0sfact/5nKub0C2xOPT7h9CV+AY19P+H2 DdcGfyH3GA9ge6hK5bjHFqN0/YcLYyavtesUe646QYOLostWIuKFMiz9b3+GAWYlNmp7 uNUg== X-Forwarded-Encrypted: i=1; AKwUvBz+0YWy7SGS6oB2qaliV1x0UPJjsHLNxN2yB43b5v/E6/cx8pycnsjAPpkSuL1b+p0Cd8kUAGw=@vger.kernel.org X-Gm-Message-State: AFuF++n23zT1MRbh5aNtZRPD/Bj3ZKm6huVW1Bh3iVknbftPzy9iFR5M h5rIvQSjLnACgMW5rIZqedxC9zG+30j2aQg7w7b2zClry/KaXlKifuNDMZvv7vpJXnMs2uN5sdf d8ZkYbgNLSF1frA== X-Received: from dybla10.prod.google.com ([2002:a05:7301:1a8a:b0:32e:7e7e:22ff]) (user=cmllamas job=prod-delivery.src-stubby-dispatcher) by 2002:a17:903:2410:b0:2d9:2b1b:878a with SMTP id d9443c01a7336-2d9526c2cdfmr76986075ad.10.1788295976098; Tue, 01 Sep 2026 13:52:56 -0700 (PDT) Date: Tue, 1 Sep 2026 20:52:41 +0000 In-Reply-To: <20260901205250.1638304-1-cmllamas@google.com> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260901205250.1638304-1-cmllamas@google.com> X-Mailer: git-send-email 2.55.0.966.g6673acef38-goog Message-ID: <20260901205250.1638304-2-cmllamas@google.com> Subject: [PATCH v4 1/7] 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@google.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; -- 2.55.0.966.g6673acef38-goog