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 7713E3C0A13 for ; Mon, 31 Aug 2026 22:41:55 +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=1788216116; cv=none; b=TZ888UHnItpgzfWYfoDGRQmK++HKtvNQXolc0AL6ac7QrI5zP+Nq4bTmq+cMdA3KU2Cv/1jiFcHTS3MYR6xheBHX3slF/Q1mkuMpshWwYhtcWC6rkwansg6UghIMyUdp6RIok3S2z0YhAeGSPhRhT6OAw/d2C5maW5rsLhA1qg4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788216116; c=relaxed/simple; bh=8KcSgffxAkB1OeS3/kdkp5OoiPWVBES6SdR64YQAb54=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=IsWQdVnpPgRB3Rqgghp1K02Q9Zide52MBxbaAcYMWWQs1YLk/9OoxekEQhIiez6WRRLamEz+X3Jwp53oeQRQAiMbIl+JT0eJ9+Vxt4OoLWDJArA0MGqRG6NzpY4720aCtbUVAP3/nU1YV0MXVm5EFQZjVRq3bEnWY288UlHV5/Q= 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=jiyY/yvL; 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="jiyY/yvL" Received: by mail-pj1-f72.google.com with SMTP id 98e67ed59e1d1-398d0010cfaso3679813a91.3 for ; Mon, 31 Aug 2026 15:41:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1788216114; x=1788820914; 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=wgNVfGlbCEyq8MC5JaRKbxi7I9+N7W9TiHIhv9t8nRg=; b=jiyY/yvLq8zk3oUJC3zOdbHSqm+FdrxR+ukT4OdfNd4xjG2FVzB9p+g8DlkulPIlHS 1wWWSJrIVCtWjVx7aCU5SXaR7Kf/7fTFuUpd2oL5/uf4ZDlAN2zoa51mxfcLoK89YcKF s5dRicloBc8VOfGf18dofHObNKoN/1F4vAijTWQXvIsw2UpD1kBGEfCEH8QB/qW62mt/ ywhWb46RhSkUQDFHl6mpHYJ0rBmFhMULbpo46T4i7rzc8Bm66bLha2ZWUn+pvccsl6Mv pHFf5zWtEqKiyeHtYMSm/hd2RPxkkFmBAyiT6/C1n1f+ho0VBTL40k+7MRQ9B/VVpNG7 1+sw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1788216114; x=1788820914; 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=wgNVfGlbCEyq8MC5JaRKbxi7I9+N7W9TiHIhv9t8nRg=; b=PS2yfhjh6yN4AcMAjoibuKsObO3jFQOsxVbkKgugsHvvHKdJDA+xPlVlgddgTVBj5F UuQN9VP9EzBTFnExL51+Pk7cjZBkoA1G/QFcquqbMO0PrFXiXXi29FNyN4XFZARVPRk4 gd11r+EdzV3fUi5bXgHfMCfxwBsbSNX4/mw5nC3K5h7gyGp9wNpBX7msMJd84VZaEnI8 WFe4uytaEB3fpKv7xsh2FJ8Mg6zhXR6HjfC9iFE/H7/KSUJnGHg/a2/L0UExzPZDIoBr wRGNTyamR8jPyvT6/QSoroYaMJie+6A+5MGIFXc2s4cTcB7Cv4QZLdiipOjIhwANA3zI K+6w== X-Forwarded-Encrypted: i=1; AKwUvBwNoIt2lICoRUBSPT7PYJAJ3jtUw2SOQNHNuQQnwX/r8iDdhvMIRXRPgF7VHwWJl+um/t50UQ1Yggx9MXQ=@vger.kernel.org X-Gm-Message-State: AFuF++mbFy233dC2wsCtOkW8JbDoOs/OSyplq4XqOLBiPGyqsyYjq89z 7nIvL3fGJ3i0/6Cge/243Wqi3pwk0iE53yFVPEaVImNf5euiX+OfiPn5YHtzIP3s0/SRvNtwq+L i/jfg9j6ShrpdSg== X-Received: from dybgt40.prod.google.com ([2002:a05:7301:2228:b0:327:adfa:8682]) (user=cmllamas job=prod-delivery.src-stubby-dispatcher) by 2002:a17:90b:4cd2:b0:38d:fda6:4873 with SMTP id 98e67ed59e1d1-39907d0970fmr5248962a91.10.1788216113543; Mon, 31 Aug 2026 15:41:53 -0700 (PDT) Date: Mon, 31 Aug 2026 22:41:43 +0000 In-Reply-To: <20260831224145.169403-1-cmllamas@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260831224145.169403-1-cmllamas@google.com> X-Mailer: git-send-email 2.55.0.897.gb25b4bd76c-goog Message-ID: <20260831224145.169403-2-cmllamas@google.com> Subject: [PATCH 2/2] 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. -- 2.55.0.897.gb25b4bd76c-goog