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 E8B9947A87A; Sat, 12 Sep 2026 12:32:52 +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=1789216374; cv=none; b=I0fPoF8W4B90wB89Upa35CkzMVoYtCvS1DCZWpWYilxkmr/NUkRrnExsynpgk42oc0RiAxIp6YSiXEVk7ZhqB6c0ipZmHuRQZfYUQuqBHSd2ssEMI43Nsj7KyKXwTWG5VSlAvzb5c7fD3Cw9uGPQ6pS+f1Z+zEJBSSXxkYqXFFQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789216374; c=relaxed/simple; bh=KYcV1moxWqm/UxJy9BK9YZPgkNHYa6oU3imYZYxVA2o=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=YfKtGWOHDBsr+ZAIdpDYKqCZ+cQlUA9pYiI0i8fuVA53BCs8AH0zqwdZgk3CESFnMs7zw5ITpdbEgebAczF9sifmNke6YH6shcb/hXWZZ3wcAJ2amgy2iOKbXlzsKR0tEFsdh0GAzvEjKxf52fnITErHYSh43Ic2CxThkDi2NcY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=1ZbroQGA; 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="1ZbroQGA" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 451401F000FF; Sat, 12 Sep 2026 12:32:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789216372; bh=Sh53rNPZ8uVFNOThMMoTP5PQfihu0T/RB+LB6eVSmqI=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=1ZbroQGAwHGPblqA/dRkRY1RMTczr1TeWp1IwAUOc2nIO+q/iE6d2OKa9dCSrTIYu gagRxVBfhy68PefgfKqL+rlEr059u60NMtlozaDPx7+vDCh6Vzr4DzZ3zAAbjWDNWX S+BXi7zEYjsV088Ocz7mimubIvzLUi6NMjw+E9Vg= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Leon Romanovsky , Sasha Levin Subject: [PATCH 6.12 0723/1376] RDMA/mlx5: Fix stack out-of-bounds read in cc_params debugfs Date: Sat, 12 Sep 2026 08:52:29 +0200 Message-ID: <20260912065623.654295171@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260912065607.535295758@linuxfoundation.org> References: <20260912065607.535295758@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 6.12-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