From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 45B2BCD5BD0 for ; Wed, 27 May 2026 20:50:53 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id A74B110E9FF; Wed, 27 May 2026 20:50:52 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=google.com header.i=@google.com header.b="bHLbiJCO"; dkim-atps=neutral Received: from mail-qv1-f73.google.com (mail-qv1-f73.google.com [209.85.219.73]) by gabe.freedesktop.org (Postfix) with ESMTPS id D9D0710E9FF for ; Wed, 27 May 2026 20:50:51 +0000 (UTC) Received: by mail-qv1-f73.google.com with SMTP id 6a1803df08f44-8ca1295e3a9so222487646d6.1 for ; Wed, 27 May 2026 13:50:51 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1779915051; x=1780519851; darn=lists.freedesktop.org; h=cc:to:from:subject:message-id:mime-version:date:from:to:cc:subject :date:message-id:reply-to; bh=OnsOZAwcaFX6qrXTkZ3llO87kDjoRN0331vlXYrms0w=; b=bHLbiJCOvdaVlLzCeQN7qKkefJFCMAeKHrAzcGoBSE6U34Bh3ToqVTejJJNjVPT034 7ZXm53kNTU1zbyCjmyomRH7/TN0WT4XEJt09HM8C38ZnyME+c2kDKucoOhFn0S9FbSds ug7WgUM7OHZBPO65XNyXGY+57KFi50KmDbuV2UUwW7u5iv1fIOUJicxL+uZhS2AXefH7 xQ1yYGRHZdNV+pfvTCsJkDnq2rF5txoeyf2/lMd3ivSuCX4mEOYk+YplAEx6qid0nVsK RjJDw4n+kvj7LksoOu7cdwb5Iz9DxMb58FnJZEckdfmBUf9aT5AvgkzdOfvL0zoNB0zk CYLw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1779915051; x=1780519851; h=cc:to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=OnsOZAwcaFX6qrXTkZ3llO87kDjoRN0331vlXYrms0w=; b=Tmuv4hkDGSCyCqMvYrCkrikLBxfNGLrhqWbmBVXa7E9phI0dzdrj90BhlCXxDzZIko 85K+ylV71DX5GyUaUicsBAzCsjG1jNDo+B2w5kfHF6Bm5Lkjxj+H6krKkdeQvUw3FA0m iixQ5xYHQ58cx1LC7h6oR3jsnn+wWDJSm5S6ND36j9vC+KNufBO6nRbP/hHKGRwPG/rC 6PYe4wEpGNzDN67Q8gCkNHPv4UhCEfERcBDl+oTxsf2uBWz/TzM+s4iwFeOXuutxuR/B aVPvhGAnNNzrAblg6lVJEMC09n6FyvlBFf9QfK9LX2JrhEjko+/DuXel765rP+faIAys m+vA== X-Forwarded-Encrypted: i=1; AFNElJ/x9YL08+z+sBRIZmN4EPDeJprYWsZgX0wOeHoHmOEumvAba5rrXtri9MKK15WAozCY+pJ9NY0HSIc=@lists.freedesktop.org X-Gm-Message-State: AOJu0YzlEDhqgT3auYWP8yUm8TO64oMp+JnnxRIww1hfG+L0WY8890nF Pnzv/MHZLDdFtDIz3h9MvLA93hE2IfGj/j0cI6+cNy3KmfgqPeBa7bsZ0PGwTl4ChMk5UVG1i+T NCXt8qahcL5gX X-Received: from qviu6.prod.google.com ([2002:a0c:c486:0:b0:8cc:2486:6603]) (user=xuehaohu job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6214:54ca:b0:8ac:b237:9fb5 with SMTP id 6a1803df08f44-8cc7b5fe0d8mr387104406d6.49.1779915050519; Wed, 27 May 2026 13:50:50 -0700 (PDT) Date: Wed, 27 May 2026 20:50:47 +0000 Mime-Version: 1.0 X-Mailer: git-send-email 2.54.0.794.g4f17f83d09-goog Message-ID: <20260527205048.2168808-1-xuehaohu@google.com> Subject: [PATCH v2] dma-buf: Fix silent overflow for phys vec to sgt From: David Hu To: Sumit Semwal , "=?UTF-8?q?Christian=20K=C3=B6nig?=" Cc: Kevin Tian , Ankit Agrawal , Jason Gunthorpe , Alex Williamson , linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org, linux-kernel@vger.kernel.org, jmoroni@google.com, praan@google.com, leonro@nvidia.com, David Hu , stable@vger.kernel.org, iommu@lists.linux.dev Content-Type: text/plain; charset="UTF-8" X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" In case MMIO size is bigger than 4G and peer2peer DMA goes through host bridge, we trigger a code path that assigns the total linked IOVA (which is greater than 4G) to mapped_len. Previously, `mapped_len` was declared as 32-bit `unsigned int`. When accumulating `size_t` lengths, this leads to a silent wrap-around. This truncation causes truncated lengths to be passed to functions like `fill_sg_entry()`. Fix this by changing `mapped_len` to `size_t` (64-bit). While at it, fix similar potential overflow issues in `calc_sg_nents` by using `size_t` for `nents` and checking against `UINT_MAX` and using `unsigned int` for the loop iterator in `fill_sg_entry` to match. to mapped_len, and leading to a silent overflow Fixes: 3aa31a8bb11e ("dma-buf: provide phys_vec to scatter-gather mapping routine") Cc: stable@vger.kernel.org Cc: iommu@lists.linux.dev Reviewed-by: Pranjal Shrivastava Signed-off-by: David Hu --- Changes in v2: Fixed 'IVOA' -> 'IOVA' typo and expanded commit message (Claude Bot). Added Reverse Xmas tree formatting (Pranjal). Folded in extra bounds checking for calc_sg_nents() (Pranjal). Folded in type consistency fix for fill_sg_entry() (Pranjal). Droped unnecessary `nents = 0` initialization (Claude Bot). drivers/dma-buf/dma-buf-mapping.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/drivers/dma-buf/dma-buf-mapping.c b/drivers/dma-buf/dma-buf-mapping.c index 794acff2546a..5bc769fc42ea 100644 --- a/drivers/dma-buf/dma-buf-mapping.c +++ b/drivers/dma-buf/dma-buf-mapping.c @@ -10,7 +10,7 @@ static struct scatterlist *fill_sg_entry(struct scatterlist *sgl, size_t length, dma_addr_t addr) { unsigned int len, nents; - int i; + unsigned int i; nents = DIV_ROUND_UP(length, UINT_MAX); for (i = 0; i < nents; i++) { @@ -36,7 +36,7 @@ static unsigned int calc_sg_nents(struct dma_iova_state *state, struct phys_vec *phys_vec, size_t nr_ranges, size_t size) { - unsigned int nents = 0; + size_t nents = 0; size_t i; if (!state || !dma_use_iova(state)) { @@ -51,6 +51,9 @@ static unsigned int calc_sg_nents(struct dma_iova_state *state, nents = DIV_ROUND_UP(size, UINT_MAX); } + if (nents > UINT_MAX) + return 0; + return nents; } @@ -95,9 +98,10 @@ struct sg_table *dma_buf_phys_vec_to_sgt(struct dma_buf_attachment *attach, size_t nr_ranges, size_t size, enum dma_data_direction dir) { - unsigned int nents, mapped_len = 0; struct dma_buf_dma *dma; struct scatterlist *sgl; + size_t mapped_len = 0; + unsigned int nents; dma_addr_t addr; size_t i; int ret; -- 2.54.0.794.g4f17f83d09-goog