From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 1C825C56207 for ; Thu, 6 Aug 2026 14:46:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=S5nNvq4xaxP+Td89jLEXIwCMlG64uS80UP5U7rijSgA=; b=L9Zr6yfowPGPvEazWyv29jkG0k sWWEJAw/FwRRT1ra+9II9xzJG97SxnCSBUkDm44TbOG7ud0bPrGKYTYDL3cNANiamjBqcf9o+yrsR fNmTITkRNRywuuQ+z/v8BVmKA984LGjp5LZLydx7sTPOw4MJu2lOYXm3++iSk8yA3450LwmYi63cu cGPfwZwfJZr/ipZehvmzA+YE2BHBt3gl9zevESfojwDpFG9xw490I+48V/Q8sdfYbvdZZ4xysVpyU bNtvtQXw/qiGfe/sFmW2XZXp/eHnhDl+hxTO3HstW3KjdEc/e7JIoroMnxV7Vr9aNs+HK46vuwgd2 qV4YgCLg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wrzMv-000000061bR-3KHl; Thu, 06 Aug 2026 14:46:49 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wrzMt-000000061aH-2jCW for linux-arm-kernel@lists.infradead.org; Thu, 06 Aug 2026 14:46:49 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 1BAC419F0; Thu, 6 Aug 2026 07:46:41 -0700 (PDT) Received: from e134344.cambridge.arm.com (e134344.arm.com [10.2.212.8]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 7CEE63F9A2; Thu, 6 Aug 2026 07:46:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1786027605; bh=YEqhi0ns9dOGIwkKaThAPGwuXkqZjMn1/micDNziDLY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=j4qyDf51HPdHHwZ35q1LnwXeGXMd+tqFMfkZh8KVXk806CqCOX4YXKR1PzJvd+ck+ Af1EUm+0rhxhjXMqXOjclSpKqmpf5FrDpzDI55QTwpTzsC0CCAFJpnrjqrpkPsaqMU ESnfaRRardigZ3zp2H0nxM9EGleAssHJi3ePJLos= From: Ben Horgan To: ben.horgan@arm.com Cc: james.morse@arm.com, reinette.chatre@intel.com, fenghuay@nvidia.com, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, dave.martin@arm.com, andre.przywara@arm.com, will@kernel.org, catalin.marinas@kernel.org Subject: [PATCH v1 1/2] arm_mpam: Fix a NULL pointer dereference on unbinding after an error interrupt Date: Thu, 6 Aug 2026 15:46:30 +0100 Message-ID: <20260806144631.2502918-2-ben.horgan@arm.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260806144631.2502918-1-ben.horgan@arm.com> References: <20260806144631.2502918-1-ben.horgan@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260806_074647_758507_219C3BF7 X-CRM114-Status: GOOD ( 11.47 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org If a user unbinds an MSC after mpam_disable() has been run in response to an error interrupt then a dereference of a NULL pointer occurs as mpam_disable() sets the drvdata to NULL. Add an early return to the driver remove callback to avoid this. Fixes: f04046f2577a ("arm_mpam: Add probe/remove for mpam msc driver and kbuild boiler plate") Signed-off-by: Ben Horgan --- drivers/resctrl/mpam_devices.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c index 2f09f4b78bd3..bc6cc0b5c96b 100644 --- a/drivers/resctrl/mpam_devices.c +++ b/drivers/resctrl/mpam_devices.c @@ -2025,6 +2025,9 @@ static void mpam_msc_drv_remove(struct platform_device *pdev) { struct mpam_msc *msc = platform_get_drvdata(pdev); + if (!msc) + return; + mutex_lock(&mpam_list_lock); mpam_msc_destroy(msc); mutex_unlock(&mpam_list_lock); -- 2.43.0