From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794048377; b=RgfdRdR2DPTBxNRG4z9dPUoFNd2XrgfWtzHdL3NxHegg4JmZTFqWoZV0rIbV2wR/3vFs 9/Vk/sBzTi5COj9xYk8shDOT0JcEHX/sfJVwlV5X+9Y6DApjS3ur4wwwOoG8kf5DAJ29q 3ntdo3JNJDb/yu1xbA0PqQiOXIjcX4vuQzqeTdSjz2i+E+1zVulQK8ISjHi50XN5/DW5m 7WnZ4phXrJm7ik6wlVCjNxHw5xs1vE0hlMKk5Hg6/nAr74MoqvU/hsiSb5BdISPbVLsQQ DCfhFgJS5hUe0wIeLm65IVLPMoLnHv0L9NPLNvPE7go/6HFo+i5VahxeJmg9ovnQlGg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794048377; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: MIME-Version:Content-Type:Content-Transfer-Encoding; bh=SzZHqVbybIB5CEXs+00sU+pkM3Dtbr4nnDDqjgyu8Sc=; b=TMUe20GgKRn47VNiyUCfmEIwD28uDBaebYObgM/6VaIJ5oex1agGW9XaDerxQWOeX8MH IWbmH3lQoRYMN2/YSBlaCBiNUUaI3pFLP5osOsINcVZBDGu8uNjhtvvB8IsQsWPtoq3Sb nkc7HySjR+t6EFl4Tzjxg1MxmlSnHeYQ2vNXnBQvl1HhuNy3fuLbqyRa74wdVZ1//AhDT D4d6Y5IZbpcGcCh1whhHPv5duaL42iIMrlY2tcbVDI3jQJtQl6D0aJpqqzTWVVvQk2Xfr 2WQ+xvtnl4jJ+3oaDIGWKi70EDsVp0bNAXlyRgociqskRK89lEvcFRHtKHyw0XtAXrA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=fzIywKnn; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C6C1D606A326 for ; Sat, 7 Nov 2026 10:46:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=fzIywKnn Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1AEBE1F0089F; Sat, 7 Nov 2026 10:46:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794048376; bh=SzZHqVbybIB5CEXs+00sU+pkM3Dtbr4nnDDqjgyu8Sc=; h=From:To:Cc:Subject:Date; b=fzIywKnnIrhOz3PsWnUT7PnU1eMX3rOxxQ6xjwAD1Y4bpx0es+NHnc+HxfR6tm9Uw ZfYEwxTeGPFXoXRpN+lSK6zwjMtiT244nLH14ORh2oGe0DSRAr5O/j8HElhjT3bIs6 qGwPdQbhlh6Q4auvcARzC6pEX/G5Sq66hGudDQNf55H7kUu+WdNCdMOErLkpK3OBGC LuGnAwYtNRlIa0DGziBaaXndRNEzL5RJvlqZw2t1650BIkDO5vJdl8W1yzk7iFZjn2 0mONKlzUaktggsSDQo8+bQ0Q6YCKk0IE4tuB+koBfmQqaaT1Fnv+dX+nOu/rjYJ87K F6gMKj8telbpw== From: Sasha Levin To: krzysztof.karas@intel.com, robin.murphy@arm.com, sebastian.brzezinka@intel.com, joerg.roedel@amd.com Cc: stable@vger.kernel.org Subject: FAILED: patch "[PATCH] iommu/dma: Catch scatterlist length overflows" failed to apply to 6.1-stable tree Date: Sat, 7 Nov 2026 05:46:14 -0500 Message-ID: <20261107054614-failed-6.1-1c8f6308e557@kernel.org> X-Mailer: git-send-email 2.53.0 X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The patch below does not apply to the 6.1-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y git checkout FETCH_HEAD git cherry-pick -x 1c8f6308e557f32412e9d4678b3f029f47f6d9aa # git commit -s git send-email --to '' --in-reply-to '20261107054614-failed-6.1-1c8f6308e557@kernel.org' --subject-prefix 'PATCH 6.1.y' 'HEAD^..' Thanks, Sasha ------------------ original commit in Linus's tree ------------------ >From 1c8f6308e557f32412e9d4678b3f029f47f6d9aa Mon Sep 17 00:00:00 2001 From: Krzysztof Karas Date: Fri, 2 Oct 2026 05:33:20 +0000 Subject: [PATCH] iommu/dma: Catch scatterlist length overflows It is possible, when a very large mapping uses only one scatterlist, that padding overflows scatterlist's length field. This results in: 1) silently wrapping the value 2) smaller than desired mappings produced by iommu_map_sg 3) leaving mapped bytes in memory (no iommu_unmap) Address this issue by adding overflow detection for scatterlist length field. Fixes: 809eac54cdd6 ("iommu/dma: Implement scatterlist segment merging") Cc: stable@vger.kernel.org Assisted-by: LLM Signed-off-by: Krzysztof Karas Reviewed-by: Robin Murphy Reviewed-by: Sebastian Brzezinka Signed-off-by: Joerg Roedel --- drivers/iommu/dma-iommu.c | 20 +++++++++++++++++++- 1 file changed, 19 insertions(+), 1 deletion(-) diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c index 1b80121232322..c19f668a7be9b 100644 --- a/drivers/iommu/dma-iommu.c +++ b/drivers/iommu/dma-iommu.c @@ -1478,6 +1478,11 @@ int iommu_dma_map_sg(struct device *dev, struct scatterlist *sg, int nents, sg_dma_len(s) = s_length; s->offset -= s_iova_off; s_length = iova_align(iovad, s_length + s_iova_off); + if (overflows_type(s_length, s->length)) { + ret = -EOVERFLOW; + + goto out_restore_sg; + } s->length = s_length; /* @@ -1494,7 +1499,20 @@ int iommu_dma_map_sg(struct device *dev, struct scatterlist *sg, int nents, * time through here (i.e. before it has a meaningful value). */ if (pad_len && pad_len < s_length - 1) { - prev->length += pad_len; + unsigned int new_prev_len; + + /* + * For large mappings spanning multiple GBs we + * may not be able to fit all needed padding into + * sg->length. + */ + if (check_add_overflow(prev->length, pad_len, &new_prev_len)) { + ret = -EOVERFLOW; + + goto out_restore_sg; + } + + prev->length = new_prev_len; iova_len += pad_len; } -- 2.53.0