From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj1-f71.google.com (mail-pj1-f71.google.com [209.85.216.71]) (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 5F16C48422E for ; Tue, 1 Sep 2026 16:35:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.71 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788280534; cv=none; b=SOH8myuBB76dzaegA/ObPgbqsZgHw5UAV5J3qKoM3bO41sy8pueva9eLl8PqlaDlAWCzG4sxF/GcMxH1FSeOo04AiBsB/vTuN+MnZ2tdK7FPDGp4KIaKkz5vC2hrNiPE30c5SEn6qMysiQqxdrGA7daozk+wFCkbZh6UtVJU4eY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788280534; c=relaxed/simple; bh=xMfXa4JJaYVx9CY7Y6p7EK/bnTHLTV7vxrHNWHGqnw4=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=L7g49fggVDUaJJ+NGUecdKvajTKTwmLaRCkF6EV3iYTzmBBJ/EitQ3qCy7rkbWHWfiSROjmQ+qm2ImMpFH1tsNtQojcwVo1txQ0m1yQ8cV8AW6KjthnJw5NesHMmW3nnYSdnHKq7olcgaBZqbxEDtEPWl5mkAkBxj3xf2ty7Nhc= 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=D5afQhUS; arc=none smtp.client-ip=209.85.216.71 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="D5afQhUS" Received: by mail-pj1-f71.google.com with SMTP id 98e67ed59e1d1-398fe469aa0so4261a91.2 for ; Tue, 01 Sep 2026 09:35:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1788280532; x=1788885332; 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=KLMvfa5EimRkqQR6s886FTBUek6ludb5m9DiCXoQ59o=; b=D5afQhUSM5tSEqF5VeLaVVdHPhn14vTgeoQDIGVf9cY3mo1+mcw6SfROFMsNxsOYNi igXoHhQwYCb5+CngqmaFqmjtueUcHtZ7S0EcnvFUXBJelYkYu0vAhX29RRSEn4rV/iWS 3OSedlfAxJth/HgvP6dDshYQEhWaDAVPuFETkdIFv588O39+bn0aXXm1Ug2tME2K+Kkp TaUvb+Kaf37A3RDW9MntKAW2hQpCRSoirwiV4djgVS9Dk3wMktCTO/4tjsIXvIq14lni eeyEImBp3F2yteBP+FUgw127Za6tSQTnEHxVVHAV9QvoZZaItk5N9NNWZTg1UDNAmJWz A+RQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1788280532; x=1788885332; 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=KLMvfa5EimRkqQR6s886FTBUek6ludb5m9DiCXoQ59o=; b=jdeMp1pHNjxpvo24CDLMQHfYtD85vNswHpTgP8kOOTDcIxLGxEL3dZYAK93zvmQGP1 MpUgqB3AyQ/scnE13HMP36rTHRGRZ6FNqBY9IJ0CotHa8R324uUWEqJKGb2zM5P4CY0m +OXynDA1rLMxtK/MH/4YZ2RdEGu13nOmcvpR97B4/ALSQ9A5Oe6cjeql70bcgX3WrYOW Yd12AK36TniwRPnR5Qy5w8dln53ezii5TDEYCRn2PsNXVAoy18NanhdnKYFTwAuOoK+U yZJH3r0I88qllymKaRTCw3drmnutr5VaSWw6xOSexQZgIXWVn2og3E1esg3cLRWPvaIr MR7A== X-Forwarded-Encrypted: i=1; AKwUvBxj9IkPwIS+R54kIa5Yi5k71E0NPGBnInyZ6KUWbwQVHP0FFdIDI0ZAVeI2qsNogzveWKNNN+1Joy8Z5LbsxA==@vger.kernel.org X-Gm-Message-State: AFuF++mqf7bJcMKQueY+hgUaLUxextBIZIdh3RlMrUaiWWSVuUKNE5Sf 3lUKnkQNmbY/RhIE/HPGkUjAwpEOwMfwgNNGWFNyug0Yth7Sk6i5cuciB4+Ns1PBdwrHQoSguwu KARkPyJIdk4GNqQ== X-Received: from dycna14.prod.google.com ([2002:a05:7300:ea8e:b0:328:665b:a9ce]) (user=cmllamas job=prod-delivery.src-stubby-dispatcher) by 2002:a17:90a:d407:b0:398:e73e:5a13 with SMTP id 98e67ed59e1d1-39907bbe00cmr15099714a91.9.1788280531343; Tue, 01 Sep 2026 09:35:31 -0700 (PDT) Date: Tue, 1 Sep 2026 16:35:18 +0000 In-Reply-To: <20260901163521.1355535-1-cmllamas@google.com> Precedence: bulk X-Mailing-List: rust-for-linux@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: <20260901163521.1355535-6-cmllamas@google.com> Subject: [PATCH v3 5/5] rust_binder: reject mremap() From: Carlos Llamas To: Greg Kroah-Hartman , "=?UTF-8?q?Arve=20Hj=C3=B8nnev=C3=A5g?=" , Todd Kjos , Christian Brauner , Carlos Llamas , Alice Ryhl , Benno Lossin , Gary Guo Cc: kernel-team@android.com, linux-kernel@vger.kernel.org, Suren Baghdasaryan , stable@vger.kernel.org, Sashiko , "open list:RUST [PIN-INIT]:Keyword:bpin-initb|pin_initb|PinInit" Content-Type: text/plain; charset="UTF-8" Binder does not support mremap() as it caches the mapping address in Inner::vma_addr. Moving the mapping breaks the IPC communication for the process and can temporarily leak pages during a shrinker reclaim. Fix this by explicitly rejecting the .mremap() operation. Cc: stable@vger.kernel.org Fixes: eafedbc7c050 ("rust_binder: add Rust Binder driver") Reported-by: Sashiko Closes: https://sashiko.dev/#/patchset/20260813193433.3318288-1-surenb%40google.com?part=2 Signed-off-by: Carlos Llamas --- drivers/android/binder/page_range.rs | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) diff --git a/drivers/android/binder/page_range.rs b/drivers/android/binder/page_range.rs index 52ffbf3504e7..411efcc2116f 100644 --- a/drivers/android/binder/page_range.rs +++ b/drivers/android/binder/page_range.rs @@ -24,7 +24,7 @@ use kernel::{ bindings, error::Result, - ffi::{c_ulong, c_void}, + ffi::{c_int, c_ulong, c_void}, mm::{virt, Mm, MmWithUser}, new_mutex, new_spinlock, page::{Page, PAGE_SHIFT, PAGE_SIZE}, @@ -144,8 +144,17 @@ pub(crate) struct ShrinkablePageRange { _pin: PhantomPinned, } -// We do not define any ops. For now, used only to check identity of vmas. -static BINDER_VM_OPS: AssertSync = AssertSync(pin_init::zeroed()); +unsafe extern "C" fn binder_mremap(_: *mut bindings::vm_area_struct) -> c_int { + EINVAL.to_errno() +} + +static BINDER_VM_OPS: AssertSync = { + let ops = bindings::vm_operations_struct { + mremap: Some(binder_mremap), + ..pin_init::zeroed() + }; + AssertSync(ops) +}; // To ensure that we do not accidentally install pages into or zap pages from the wrong vma, we // check its vm_ops and private data before using it. -- 2.55.0.966.g6673acef38-goog