From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 306A2326D44; Tue, 21 Jul 2026 17:42:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784655735; cv=none; b=BOrb7nrrfPHkMkTGR5YX6smaseQ8ixJhiYoc7Iq8VeLmaB9dQ+ehBfIbXfHyBtv5RlK41lqjKQGdLm9p/tJc7Sh2WFVPgndi2sPcEyI6GZcM33L8vDIuwPrs34dphnEHYHgp96BH29h8eKBfBdJdbcdeFViXUg4D6G+lULkFFwY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784655735; c=relaxed/simple; bh=I5zMCXptW2cj3Z7VTngf1/NDU9zZKEhDI+stdbb3MN4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=aspQj5IbwAKBXI+LTgqKXVT0lvhrJOz85EPxHJrhh5hzIETiIadEG72A9PDl9taTZ+pS8CEYhjG88gP7DgmQQjuxo3F7nA3xFu/B/KMGQusZv1j+f2JHpyQQYmh5BcUOjhG8iCATyBYDu8V2HCOZzzlh3C2x/+1vnF6cNfyau2Y= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=eE2DpNrl; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="eE2DpNrl" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 50BC81F000E9; Tue, 21 Jul 2026 17:42:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784655733; bh=1CYLJLf5R/DAIJ3XMIY5OTHN/nHrdfFsjzmd10s1eJc=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=eE2DpNrlNIj+r2x9jbzNSM89X5dqd8NwXMZnCxyRqm0Zeu/k9AhYtE1czkWIz/Opk TYuAGVq9bwrtrhf0te8Y668poCuGHLnVfaC9++c+arHJqRqqlrn84GcRKmRHWUj9b/ lwW4o81o8Cy2gPhp7WUQgjxZ01OJkgGeLulImPBQ= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, "Tycho Andersen (AMD)" , Herbert Xu , Sasha Levin Subject: [PATCH 6.18 0121/1611] crypto: ccp - Fix snp_filter_reserved_mem_regions() off-by-one Date: Tue, 21 Jul 2026 17:03:57 +0200 Message-ID: <20260721152517.580512119@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260721152514.750365251@linuxfoundation.org> References: <20260721152514.750365251@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Tycho Andersen (AMD) [ Upstream commit 1b864b6cb213bbd7b406e9b2e98c962077f300df ] Sashiko notes: > regarding the bounds check in snp_filter_reserved_mem_regions() > called via walk_iomem_res_desc(): does the check > if ((range_list->num_elements * 16 + 8) > PAGE_SIZE) > allow an off-by-one heap buffer overflow? > > If range_list->num_elements is 255, 255 * 16 + 8 = 4088, which is <= 4096. > Writing range->base (8 bytes) fills 4088-4095, but writing range->page_count > (4 bytes) would write to 4096-4099, overflowing the kzalloc-allocated > PAGE_SIZE buffer. Fix this by accounting for the entry about to be written to, in addition to the entries that are already allocated. Fixes: 1ca5614b84ee ("crypto: ccp: Add support to initialize the AMD-SP for SEV-SNP") Reported-by: Sashiko Assisted-by: Gemini:gemini-3.1-pro-preview Link: https://sashiko.dev/#/patchset/20260324161301.1353976-1-tycho%40kernel.org Signed-off-by: Tycho Andersen (AMD) Signed-off-by: Herbert Xu Signed-off-by: Sasha Levin --- drivers/crypto/ccp/sev-dev.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c index d99726d1d57f01..563418b9e88917 100644 --- a/drivers/crypto/ccp/sev-dev.c +++ b/drivers/crypto/ccp/sev-dev.c @@ -1331,10 +1331,11 @@ static int snp_filter_reserved_mem_regions(struct resource *rs, void *arg) size_t size; /* - * Ensure the list of HV_FIXED pages that will be passed to firmware - * do not exceed the page-sized argument buffer. + * Ensure the list of HV_FIXED pages passed to the firmware including + * the one about to be written to do not exceed the page-sized argument + * buffer. */ - if ((range_list->num_elements * sizeof(struct sev_data_range) + + if (((range_list->num_elements + 1) * sizeof(struct sev_data_range) + sizeof(struct sev_data_range_list)) > PAGE_SIZE) return -E2BIG; -- 2.53.0