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 4EA4B176238; Fri, 15 May 2026 15:56:46 +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=1778860606; cv=none; b=f4rNokq2+Wg7QkQfaXrnfiEkuW/wWcmDiKyVM77GtcpSOcRN0a0TBUcqZbD0Yt99T+dDG/oISFAhYJG/J/1MgjbK/UEeDw7DnqKgu5vc8jgOakiGXiB3GZeRjdK2uZk5IALle2wVe7VNE4dO+53Xzn5UFREJDIRKNYREi05vmQw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778860606; c=relaxed/simple; bh=E2zoLuTIPzKKGqfCvLKUU96ZL1s56Eo1PLH3Cd54pAI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=YkmPN2OEBVGk6+0XEo3I5AopkO1h4jijtcpUWyn7xC/bRg5r+5fpkFBLWjLka81gvJlCqVPoxe7bFgkgKE03iAVurviqecdClYxO+vzobc+sHaITSVxjVdexhpvt81A09Qf2p7+wpEGJPYqhA5R1s1DwWHSONfuEMGSdI1XYxaI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=u+MtObkK; 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="u+MtObkK" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A58E3C2BCB0; Fri, 15 May 2026 15:56:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1778860606; bh=E2zoLuTIPzKKGqfCvLKUU96ZL1s56Eo1PLH3Cd54pAI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=u+MtObkKVeFpJG0a2Ra5xXHxSrCaLZfj7bEgFRwpI0NzVMctCyHrJDBPwXUo2WRol SofMfVDT4WpTOQkc8m4MWh5q+iA34CGziBPh7kxq2lTpxzTzMRULmdaytde180Vh4n 24HYKIwbn6Wzd/Xrj00msmZbEkCG3faD95zgWEDs= 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 6.6 010/474] misc: ibmasm: fix OOB MMIO read in ibmasm_handle_mouse_interrupt() Date: Fri, 15 May 2026 17:41:59 +0200 Message-ID: <20260515154715.277938055@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260515154715.053014143@linuxfoundation.org> References: <20260515154715.053014143@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: 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));