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 8CD28191F93; Sat, 12 Sep 2026 14:40:49 +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=1789224050; cv=none; b=lDXutCaamVW6gz95OFvgc4eoSgoF87YEsrluGzYdhXtuwQRtlbsGPcvUoVrsDJ5W0t9oU7YP+O29Coib6G2YqK6ii45S+hwgmXtmXevKt3u2uY+rIDYsVHm+LuSFn6OpHemm1ZNLErAbaJ2nwQsTsK3lR8WmD3rHtGkggj0ErXA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789224050; c=relaxed/simple; bh=ZnCjhXrT91FGP0NrDXnC3QZXWXL8CudjhqxErppSXYo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=fVRMjuYINPchTqP9g2qNZwxezKPzH7YmdW3tP1CmPGXYMcPRnRZ6t7wceuaw2nR8pCk7O5AKQoNmLi2bYVAx+cS1eCEwqd2X3Z8zMeKttvXuJH0s3dmcFawBh6zTSJujz+uB4kRQL3LGEBAbhBF/AQpOPvt8gj4eVMs6sbBVlec= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=GEDC22fL; 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="GEDC22fL" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C70EF1F000FF; Sat, 12 Sep 2026 14:40:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789224049; bh=Ra2SNG3XIePziOnW/vAIG49oIxJ6j537Mj+onlzmtrg=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=GEDC22fLZhlv7BYUb4jvPMrGt7nFukcJf5vBdz9zFggQbelSjvPpU/CpiaVnZcXQ0 QqUKktaPh0p9FnYeBipIDJexYpG8CTKwUpPAC36deowlImn+mpV/lcqebiX08200SJ n2C8qSKAk+h0fzlxWMxBDg6+zccRV7Z6ObTOrnOE= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Leon Romanovsky , Sasha Levin Subject: [PATCH 6.6 0915/1424] RDMA/mlx5: Fix stack out-of-bounds read in cc_params debugfs Date: Sat, 12 Sep 2026 08:55:47 +0200 Message-ID: <20260912065627.816790543@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260912065607.279695368@linuxfoundation.org> References: <20260912065607.279695368@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 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Leon Romanovsky [ Upstream commit 03826bc1fa6c90405bf05831f2b501a8368dcd27 ] get_param() reads a congestion parameter as a u32 but formats it with the signed "%d" into an 11-byte stack buffer. A value with bit 31 set, such as 0x80000000, renders as "-2147483648\n" whose full length is 12. snprintf() stores only 11 bytes yet returns 12, so simple_read_from_buffer() treats 12 bytes as valid and reads one byte past lbuf[]. Size the buffer for the widest unsigned decimal, format with "%u" to match the u32, and use scnprintf() so the length passed to simple_read_from_buffer() reflects the bytes actually stored. Fixes: 4a2da0b8c0782 ("IB/mlx5: Add debug control parameters for congestion control") Link: https://patch.msgid.link/20260726-get-param-leaks-kernel-stack-memory-v1-1-d61a4d39662d@nvidia.com Signed-off-by: Leon Romanovsky Signed-off-by: Sasha Levin --- drivers/infiniband/hw/mlx5/cong.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/drivers/infiniband/hw/mlx5/cong.c b/drivers/infiniband/hw/mlx5/cong.c index a78a067e3ce7f..88ac5fd1038ed 100644 --- a/drivers/infiniband/hw/mlx5/cong.c +++ b/drivers/infiniband/hw/mlx5/cong.c @@ -399,15 +399,13 @@ static ssize_t get_param(struct file *filp, char __user *buf, size_t count, int offset = param->offset; u32 var = 0; int ret; - char lbuf[11]; + char lbuf[12]; ret = mlx5_ib_get_cc_params(param->dev, param->port_num, offset, &var); if (ret) return ret; - ret = snprintf(lbuf, sizeof(lbuf), "%d\n", var); - if (ret < 0) - return ret; + ret = scnprintf(lbuf, sizeof(lbuf), "%u\n", var); return simple_read_from_buffer(buf, count, pos, lbuf, ret); } -- 2.53.0