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=1794049425; b=vY8WR6f8kF/XbWVwpzejnJZlYwstrRB2ohA6ohHN11cQSUEl6qam6qSlNAobX/ABcnTt eXUc8b8GjdoSCT0r1+GkLSg66hpQWD44qOK0wbUcc4z5SX0oO1sdDwvHpxfxoHGxbSQlR ipQ8kJyVWEZRtcxAX4xtYDl13+njjvmWX/HuEfZimQSvVCj8oqoi2YCP9UO11WTLLYA3g hepO7ZBrl6dJinTj29uTf4Pb2H01maY+6K/PSd2yaa/wmGYcOpbBjpIl3lcttYifbHjKY 9AJ518kECP9ViSvTVqH3jN4JuGIEtax+0fXudvjSalHEXLhBxoCloaxQZk4Y42YStBA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794049425; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: MIME-Version:Content-Type:Content-Transfer-Encoding; bh=/NaaTRn3N9dKDC6wT7BVWzA2umY7dpZTbY0eM6KKn/8=; b=XCF+cPLBQeeJF+ZNgLfBBk2+OFBXTWMXdsnJ8JYdNWoeGhS+DsDEzMiPMBIouwVSW28I mrD+iCx504ZIWvy7aC/YhMHzEE2YpcIfyXpyJpczoKZbGYSSGKydGgsxJPdt9EubTtwSD V+QMI1xhZp80Ebky47y2Ac68p+AlofDi2NCQfxBa7nwAFjTpZXl9T2ks/yVnB2kMJedDm r9xCHMa/rkBDIirYEdPqX4khgXQzTRPz+RLD5SDXuD+dJ6bzG2PTBzc7eyfSMSaYD9pGM ObA6aK5mhlbFUPc5PkyY7AOlz4PYM689j87F8wWyFPl2lRFEizuO0hwbqlZNHH9QrcA== 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=MFkW5nOI; 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 6B87E606A331 for ; Sat, 7 Nov 2026 11:03:45 +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=MFkW5nOI Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7319D1F0089F; Sat, 7 Nov 2026 11:03:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794049425; bh=/NaaTRn3N9dKDC6wT7BVWzA2umY7dpZTbY0eM6KKn/8=; h=From:To:Cc:Subject:Date; b=MFkW5nOIm9/WSET97LNSBUdbPn8dWF6/KfwvoN6/SaOaWoOKN4w5Xa7eEzyNu2WCi oV+t6Yyd+8X94qqeRwUdgM0yk9jnH2eGEAnaflkOb5mEUdD7s1lmU++T7/IQlaI1Jr IhKmYGY3lBqWXpzf/em1enfCVC41QsURHE++5m5wfhUxe6yW0JTpehMXpx0EM5YEnJ FK81qI+CYnEvfDIHk1zhgvZ5tmDW4T42enUGL3QTy72Ha9QNDfX81rITfMVqzRc7Mf vT68DDF+olgUdsf+VYrMAqcgBDuFPqblZR+y9YwTyT73sKUzTPIe2Uj6Mqs1ITun5F fTVuWD/WJOwsw== 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 5.15-stable tree Date: Sat, 7 Nov 2026 06:03:43 -0500 Message-ID: <20261107060343-failed-5.15-1c8f6308e557@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 5.15-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-5.15.y git checkout FETCH_HEAD git cherry-pick -x 1c8f6308e557f32412e9d4678b3f029f47f6d9aa # git commit -s git send-email --to '' --in-reply-to '20261107060343-failed-5.15-1c8f6308e557@kernel.org' --subject-prefix 'PATCH 5.15.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