From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj1-f69.google.com (mail-pj1-f69.google.com [209.85.216.69]) (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 D68B7483806 for ; Tue, 1 Sep 2026 16:35:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.69 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788280532; cv=none; b=VLXphPDn176gATs54h1uVABBrh54Kkeme5SNDPE3JDmCF3UFlYWgc/EOfBo0ubqACzTLLMUaThtr+c50lJPOSJ94/GPwxfCgY0PDFYbuq5cjORpUmXr/YF9CpaNMyzC50aeyh4tAB0DYzfVOwYbq8fhOfAUEp/F3EmkBFBtaQ2E= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788280532; c=relaxed/simple; bh=GF/bVHokF5FXjZ+g0nsyqkLr5qbnoJSW65kdmui+Z90=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=Qykww/XezP+ef157ZJGyBNzs75Nvfa4QxjWuW5ewTnzVPx1P0VLGQq8cH3mW/W8v4qrpxFfSCcG7Yg86JxSviBxQ5DqfHTUm6ov5pAjZ4dS2gavY4MP96xRgwfKHH4+sSNygAB5XBBbNVctYwZ7PDEI171XreuU/3C/hvVBFREQ= 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=vnogmpqx; arc=none smtp.client-ip=209.85.216.69 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="vnogmpqx" Received: by mail-pj1-f69.google.com with SMTP id 98e67ed59e1d1-3965ba1ba3eso12432a91.2 for ; Tue, 01 Sep 2026 09:35:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1788280530; x=1788885330; 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=P1Px1YjhukNKpiGIzc6xWlYh1IDxs7EUGnftJx4GC/M=; b=vnogmpqxe/vBz7mSfzQ9Mq+0Uw9pn6X88u21weea1t8cmt6jd1l+KGl4/Ijp3rH+fm XrEP9nNPSk6wafORYRWwLoVLVzY8kdAqz7fsQP0eTgFfSfLtn8fdeoCo+f+jMOSlKxro xNtz4zjiK28aH8pKvf0tJ7dczE7W5CpcXS/vdSVzY/wBi63kO/Hjzy8P2hp9omN/HFyD ITrrRE5yWXqj+ny1BzbctPU/CCat043XCZ/ipoXaOb1xuyasAstocJV8FUBo7zYi8AkU 4FqI1ZZTwiEVDqbEp2k/3/ZwYWTQmZc4aDuDkp8cfyKKUljuJb7hQSIAeMHpQ38DHjNO BG4g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1788280530; x=1788885330; 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=P1Px1YjhukNKpiGIzc6xWlYh1IDxs7EUGnftJx4GC/M=; b=BP2kUwIdFzW5E/fBXti4jpJBTTbV9PtwYIidTVoaulhYbWxejrIv59xLG3+//hO3Ai dTR5pbc3CzrTYcz18mxf8YZfJAPu22UIPHjR6uZ/ULIctbuUaaL4pfZfdL0/2F3Pxu3i 2vVIxlGhABlbu3wa+vk1rMAoKxDtgCTa0M3aK8vlQ7ZPrv00ulsZZbwSYFdIOEC+HOPv s6eQ0RERp9nLk7hhLm8NCU7LB2hbb5vu3uZ48Su5X2u26QYMwfAvAHM/WXrk2f8YOEBd rQgmc1StOsddZ3ASV1YokbDn4Kp5E88xlzp1g4wvNQXzY2R4roYWQ0aV8OGT8HGaKcmb gN3A== X-Forwarded-Encrypted: i=1; AKwUvBzVL5BAE/B96IUEe6IpP7TOCbrIPkEpp8iib1P6HNTt9MAxN3lgdyi6q1xQh3kPbsu2KyUNnSfXd1cSwIE=@vger.kernel.org X-Gm-Message-State: AFuF++l9Fh8Tqg+ZaGirDhFYlmkSLwti0fh/RP8brngogC/t3gX86XcL Zv08TkAcARiRbcvWbMc9T6Sz0kr8KZVpBTTaLeU5QaNWIvZX1cD7n2K2/B16N3fLucFpmwNCB4W KXaptbQ3+gd+zQQ== X-Received: from dybrx10.prod.google.com ([2002:a05:7301:4e8a:b0:314:f5d2:b3f3]) (user=cmllamas job=prod-delivery.src-stubby-dispatcher) by 2002:a17:90b:5827:b0:381:11eb:d78e with SMTP id 98e67ed59e1d1-39907d6909fmr15493354a91.14.1788280529991; Tue, 01 Sep 2026 09:35:29 -0700 (PDT) Date: Tue, 1 Sep 2026 16:35:17 +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: <20260901163521.1355535-5-cmllamas@google.com> Subject: [PATCH v3 4/5] 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 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 mremap() as it caches the mapping address in alloc->vm_start. 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: 457b9a6f09f0 ("Staging: android: add 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.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/android/binder.c b/drivers/android/binder.c index 59ff436f1138..0e6d6f6923d2 100644 --- a/drivers/android/binder.c +++ b/drivers/android/binder.c @@ -6036,10 +6036,16 @@ VISIBLE_IF_KUNIT vm_fault_t binder_vm_fault(struct vm_fault *vmf) } EXPORT_SYMBOL_IF_KUNIT(binder_vm_fault); +static int binder_mremap(struct vm_area_struct *vma) +{ + return -EINVAL; +} + static const struct vm_operations_struct binder_vm_ops = { .open = binder_vma_open, .close = binder_vma_close, .fault = binder_vm_fault, + .mremap = binder_mremap, }; static int binder_mmap(struct file *filp, struct vm_area_struct *vma) -- 2.55.0.966.g6673acef38-goog