From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj1-f72.google.com (mail-pj1-f72.google.com [209.85.216.72]) (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 64FD4415B62 for ; Tue, 1 Sep 2026 03:04:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.72 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788231867; cv=none; b=QmFaco7xTbNARohjetX3OvBDtXTs5vnLIHqNvPpDNZHF9asHtL/Uxyux0vXNSZlM4794JhMWnYf8kbw0ha1Cl35utUXu5o9N2nwC2yTRl84hWVTaCbjF39aZX5EXNe98LfhllZKjZ2LuS45k+Vaxp800SPpy6vAw3sg7DVSgiKU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788231867; c=relaxed/simple; bh=ZVDmy6VjoBuiJ9n9p6Ad1YWPKaC9lxc9NZ2K2c+ucEM=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=BPEg/5FKLAtR4SKo53dwuW/pRx3px6t7r5bi1ICDiBDa4zDUi+amr9UBghpK74GLMZ+b9w9PnxfNDzHkMda/DDyrF0UM/AybgnCqkQpqJ7KFagNNs/3ziqeWzSw3wICHl/Bd+YV+FhVpr6t/wu8SZ54Er+Y4t+lxRcXEuwGMVz8= 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=bhzRUiAt; arc=none smtp.client-ip=209.85.216.72 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="bhzRUiAt" Received: by mail-pj1-f72.google.com with SMTP id 98e67ed59e1d1-38e475f83a2so289235a91.1 for ; Mon, 31 Aug 2026 20:04:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1788231865; x=1788836665; 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=8F8BdKyQbDU8LQ8WvhzelWDzD39wCf1FJtyBP4q/yWc=; b=bhzRUiAt8cG08SVMAC6Q9OqM3zOxPbhVYTK5Lbru9MADIq8Agqore1soqohOOrpo3y 1HlR05GOHy0V3QpzdsoXGQ5GpSxzwPxbJOtvNgoh4hFZ8LdR1Gf4MgkOOTQFA89qz4Hj ehO6XqlZP8MkLZvzNr+P3TXgekS3o7Y5Qt4DRj6oaCDUL/bTO3WPeVeRCq1VGZyrYsEq XT0STyKMqMc4zjrynImJUVOYhSDd7MOgFLxGO2qOSiyaSe10MuQnuuysROTx5AJZiJGy pk7upWX+f7ZZDqV/uwDqw/22PvXdMQ1+c8eR1ticskfzWof+xUFmtDEk6Z5oFbWAGZxX op8g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1788231865; x=1788836665; 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=8F8BdKyQbDU8LQ8WvhzelWDzD39wCf1FJtyBP4q/yWc=; b=P1poJVvd1DcDWhy8yrbb1WhWoffnpJBh6SVGUBVRwYNuQzIhcFaVFKSsTOncuzo0aa /4TUeURIczi8DGPhEsn22rzWuvlQunxtBzZ66GXVoLwl0EL14wbfjq7+MwNMfsjD0Ct8 1LLtNzB6H6s1oKfXAMHKZsqhDydSq+xxyCioe9VwlGPTGeTHAvtlOslWr8WvPXTISBH5 /5qa2JBQPPnTrtRxVEruGuIvzhe7hhbi8aBXn7NeggE70IXR6Vkt4CfQnbp9wVKr3YsI EKWujqlZvB9110oG7hkj0Dt8S6mtlX59PXpY9AqRusltVyIy0UzZk6uLy900qtTPBlNt xMXQ== X-Forwarded-Encrypted: i=1; AKwUvBy5APjM1Q4Js9k9Ns+2IO5hBZ9miJJj6P6koPgcijXDJTv4UlUJXk8jcc+jn3BY4dK8H+1zdSwnNd1NJvc=@vger.kernel.org X-Gm-Message-State: AFuF++n0WIzg9gk/O33Kt6S67YXN30BWucp/7JyVUX1zXCIStCH2GW7H L+NlXCrwREg6UgDjui2uJc7r9fjzNX26ZF4chcu1XMjEZz2UQqz5lfa0Vxwuedpjd7wmyq8u+U/ GBrMzzUMRvlt0Qg== X-Received: from dlbrs15.prod.google.com ([2002:a05:7022:f68f:b0:13d:1da6:85cf]) (user=cmllamas job=prod-delivery.src-stubby-dispatcher) by 2002:a17:90a:1c08:b0:399:1b08:28de with SMTP id 98e67ed59e1d1-3991b082a7emr1620892a91.7.1788231864463; Mon, 31 Aug 2026 20:04:24 -0700 (PDT) Date: Tue, 1 Sep 2026 03:04:13 +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: <20260901030419.470246-3-cmllamas@google.com> Subject: [PATCH v2 2/5] rust_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 uses the original size to create its RangeAllocator 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: eafedbc7c050 ("rust_binder: add Rust 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/process.rs | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/android/binder/process.rs b/drivers/android/binder/process.rs index 5372bfbd93b3..9038f3d13cfd 100644 --- a/drivers/android/binder/process.rs +++ b/drivers/android/binder/process.rs @@ -1786,6 +1786,7 @@ pub(crate) fn mmap( vma.try_clear_maywrite().map_err(|_| EPERM)?; vma.set_dontcopy(); vma.set_mixedmap(); + vma.set_dontexpand(); // TODO: Set ops. We need to learn when the user unmaps so that we can stop using it. this.create_mapping(vma) -- 2.55.0.897.gb25b4bd76c-goog