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 2B922CA6F; Sat, 12 Sep 2026 10:21:13 +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=1789208474; cv=none; b=N37yvResyxOCL4QYQH/aE9DdisJTWNbWS4DUznJ+QtP6oyeIco3dv+AhD5VC3kvwYXmksF0wU+9U9sA5jjimLVKr+95Fllc+o6PlJa23yJPIg1OLBNO/eqOnzYp5NX8dAEuX8tJmajXkve2Y/xX9Dpoes3H879ZBtH7mc8xFiR8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789208474; c=relaxed/simple; bh=Fe1/rxohyaeXszamlSSyRGVyqL6o/av2YesZZbgWoz0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=FSgKMt+bUjk9pFWS9DPVp1FEVo02dC6BaIERhPQD7JBa15ZPds1oKRW6z2ZrSQdx1/y1mjqmW0tDiUhxU5p64TlBVXykYnMHUZonztNT404MDAW/3bSx51n9iFByk4ZQaYKsjx63wzyVEG0WUTOBov8cc61UfN8tw7/l7kL9QF0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=eGekuXib; 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="eGekuXib" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 30CC51F000FF; Sat, 12 Sep 2026 10:21:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789208473; bh=DrVayD/OI5pFHSMSzBZ4ESsIx9ThnUQ4S16KO2t6uac=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=eGekuXibPOvmL4il+QPCt6PxhDqwJUOkQJ2ECp+swgtMiJLBkU4mBSXcrCCvsKU5z nG9vl1WgnxMSLZ0+aK82oiVkDdWBT/2iZeXx5MriTF/g+SeSclzUM+gOB5AAxxKfnK RYeWcNMzWtQYwYy7K8gWXzYsJm7Cu74w8iasY8iQ= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Leon Romanovsky , Sasha Levin Subject: [PATCH 6.18 0624/1518] RDMA/mlx5: Fix stack out-of-bounds read in cc_params debugfs Date: Sat, 12 Sep 2026 08:46:33 +0200 Message-ID: <20260912065637.549828404@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260912065623.398859879@linuxfoundation.org> References: <20260912065623.398859879@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: 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