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 51125480DF0 for ; Tue, 1 Sep 2026 16:35:27 +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=1788280528; cv=none; b=NOHlyskh1wpzLEID5Coi/V/6JmZgfzLc93Rdm0HsBZspevxvBWv42Vog8IoaJkGLeSVB54wONabbeScTgLu8FhC657yCl5QZaSrRLZzXF6clyZDzUDUQkgRJQuAp6gCfAi/uZP8Z2NEBJRPycIXb/hkgPr4ccpRHQGOM3FB2rrU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788280528; c=relaxed/simple; bh=Ef4BVBI7qGDPlNFCmdIJj76ArTzSGUBqsa9qjOr7AUQ=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=ug+keLvbAkCBS0WZWlUlmH1UsDpal/Xnu2yZL+f+IKC7reVDM9D2ak2SQHqL6Un0VeX4tIkn1Ks6ySEr2ZdUr6W09msq9Rq2Knms1cqf8PeAEfVeOsX8YhomB0/88aHNqTPRVEWDnvyv6tJ6ObymIJtZXrrHPOcd2IeMl7qppnA= 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=BnQiAAaA; 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="BnQiAAaA" Received: by mail-pj1-f70.google.com with SMTP id 98e67ed59e1d1-38f5ac7416eso1441a91.3 for ; Tue, 01 Sep 2026 09:35:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1788280526; x=1788885326; 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=fOQzO1BwLqdJ6VWVJ7Bsn3PX5GscE0Esr+/b/xerP4U=; b=BnQiAAaAfm9xU//FEf50iWunOo7QUkAgkuNhscgqwapFJNDvFUSomFLngiA5RW2egT Pfgw4hQwPQPPmIwnQNMTf18839G0rRadDnVEnhyua11vfmuEwnUAlTX9KVe3dY1QIevR /q6OvSlGyIPJeTHm9zy6e+JFGEooJ5BFzpLG3Cz3J4fsJpwpt972QceSmtkAvznCvNfF dC7I3Xc1j4WAkT85gEK19fUzpbjHuF2gnDFZyezQhSSGlPyd3Q2ntOxQd4EwY03Vlnby SnYAmASRiFv278F9MM3s/oc3xlOvc3rdkonpubh1E4RhjXgq6Ku5vTo03uLHfndyKapZ BsFg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1788280526; x=1788885326; 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=fOQzO1BwLqdJ6VWVJ7Bsn3PX5GscE0Esr+/b/xerP4U=; b=aqq/AFLEURzI2VXcVMp25oDmHv2ddG38ubuGVXRPb7u31Ia5FI8yKNdq6EzvAUwJTp dQmw25RkyYd9KfSCv+kj8mRaM06IxRWoEBXPfN23x7aOCrTgu/qVkveYPY6eXh5m4MJL EhKvH4DiR2/P39K8yO0mfDZKqFT5Y0YHC086u0ACs2DJm1y9zoYjTidYSL8NGQhZsgpC 0854a1lTuCNzKWu5+a1yvIOPSFv0Q7WPBS4yFjOZHAaWJrT3cFGRbpLesOVGlj7PnFup IEhuRCnnHo9d7tDorVqUqRtyS5npw/3s7pTREJZBFuR0r5FW0wuYdTvQHx7DW217fSXv WdFg== X-Forwarded-Encrypted: i=1; AKwUvBzyFmoctU5OR7+BpVCDnPHr6bRnzkD7RmNeWPJ0z3jUHSFDdlAEA7fKBAnE96/W30g6DLIH69qISQVX4Bo=@vger.kernel.org X-Gm-Message-State: AFuF++mxmkG4RuaniXqSNKmBOLFfBO3QNUQWv+1PZaBEs2sJm7G+a6XO B5f/zGPtTwCk4F1S7XMYPyIBnSvYUyZYdwFfY7mh3Iz9SorFWCQc3Vmvdha3AbmfwtWn99p1u2D ddeEV2jSEYrw5OA== X-Received: from dybsr39.prod.google.com ([2002:a05:7301:71a7:b0:328:ea0:399e]) (user=cmllamas job=prod-delivery.src-stubby-dispatcher) by 2002:a17:90b:3ec1:b0:38e:7168:281 with SMTP id 98e67ed59e1d1-396d0f2dcd8mr41443991a91.10.1788280526175; Tue, 01 Sep 2026 09:35:26 -0700 (PDT) Date: Tue, 1 Sep 2026 16:35:14 +0000 In-Reply-To: <20260901163521.1355535-1-cmllamas@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260901163521.1355535-1-cmllamas@google.com> X-Mailer: git-send-email 2.55.0.966.g6673acef38-goog Message-ID: <20260901163521.1355535-2-cmllamas@google.com> Subject: [PATCH v3 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; -- 2.55.0.966.g6673acef38-goog