From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 2EA723DE44F; Mon, 4 May 2026 14:07:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777903660; cv=none; b=L8gIHAq2qsftDgTByvB+ieRM38CEMxfKKD/cmcdWwQAp8/DNSJunSCHdt+uWz1DMsXF5Ddpq0pIvTfU2yN7stbZKOf057sWNJg5+0j1ZyFm76bwXR/wY0Nwx9dyO2BofIECfvlcAJjfELJLMXw5pxu7SQfRPpOWHpanC12oLQys= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777903660; c=relaxed/simple; bh=1d1olDnkcPYe+lEJ86I/W53UtRpx+d3C7JE0EXFdxM8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=dd5ZObnUlaOif1x7Km0L3MUdtYzW/mTncb/2S9h4LETe5KFHBiE6Hgx5S4CQvMEcQnLUQg9F9hL4oFJ8mtPU4Zcq97ob2E04MJljTdsMfR4tMQEbz3iNVLV5E3Htl9CCABciSteYxc1OBM3LzRDNsXeXUEi+LOx27CDj61gNHS0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=0DX1JQ8r; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="0DX1JQ8r" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B8B18C2BCB8; Mon, 4 May 2026 14:07:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1777903660; bh=1d1olDnkcPYe+lEJ86I/W53UtRpx+d3C7JE0EXFdxM8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=0DX1JQ8rmcpophpgyZ0pEM3X3QZx0l06RIP0aIaUza37GULht3seg2+CAi97JHnu2 HJJbEeFYrVCOz/aVW7OJkTDQbcXC0f7bqIjZIRcQrSVZ4bEv76lqjPEkJp8Lw9QOTA 3fVaq1nJqFcX6+/Hc8uN6az8+GnM2JCurbr2g7eY= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Yuhao Jiang , ychen@northwestern.edu, Tyllis Xu Subject: [PATCH 6.18 013/275] misc: ibmasm: fix OOB MMIO read in ibmasm_handle_mouse_interrupt() Date: Mon, 4 May 2026 15:49:13 +0200 Message-ID: <20260504135143.432225986@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260504135142.929052779@linuxfoundation.org> References: <20260504135142.929052779@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: Tyllis Xu commit 4b6e6ead556734bdc14024c5f837132b1e7a4b84 upstream. ibmasm_handle_mouse_interrupt() performs an out-of-bounds MMIO read when the queue reader or writer index from hardware exceeds REMOTE_QUEUE_SIZE (60). A compromised service processor can trigger this by writing an out-of-range value to the reader or writer MMIO register before asserting an interrupt. Since writer is re-read from hardware on every loop iteration, it can also be set to an out-of-range value after the loop has already started. The root cause is that get_queue_reader() and get_queue_writer() return raw readl() values that are passed directly into get_queue_entry(), which computes: queue_begin + reader * sizeof(struct remote_input) with no bounds check. This unchecked MMIO address is then passed to memcpy_fromio(), reading 8 bytes from unintended device registers. For sufficiently large values the address falls outside the PCI BAR mapping entirely, triggering a machine check exception. Fix by checking both indices against REMOTE_QUEUE_SIZE at the top of the loop body, before any call to get_queue_entry(). On an out-of-range value, reset the reader register to 0 via set_queue_reader() before breaking, so that normal queue operation can resume if the corrupted hardware state is transient. Reported-by: Yuhao Jiang Fixes: 278d72ae8803 ("[PATCH] ibmasm driver: redesign handling of remote control events") Cc: stable@vger.kernel.org Cc: ychen@northwestern.edu Signed-off-by: Tyllis Xu Link: https://patch.msgid.link/20260308062108.258940-1-LivelyCarpet87@gmail.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Greg Kroah-Hartman --- drivers/misc/ibmasm/remote.c | 5 +++++ 1 file changed, 5 insertions(+) --- a/drivers/misc/ibmasm/remote.c +++ b/drivers/misc/ibmasm/remote.c @@ -177,6 +177,11 @@ void ibmasm_handle_mouse_interrupt(struc writer = get_queue_writer(sp); while (reader != writer) { + if (reader >= REMOTE_QUEUE_SIZE || writer >= REMOTE_QUEUE_SIZE) { + set_queue_reader(sp, 0); + break; + } + memcpy_fromio(&input, get_queue_entry(sp, reader), sizeof(struct remote_input));