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 92F1BC5AC7A for ; Fri, 7 Aug 2026 14:57:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=zQL3lc7HO+itcmUJdhDIhlHpBzpFG+sXQ5hsqwgnFXc=; b=hPFb4jVom3acMH snN5t5VP/OLypP+yqYBaOFBZBqzaYAKBr/Pja3i8Omw1WcKrYuwAsBa0dCCgSb+KTFT6RKJXbw8ct j/23e7i6fnlaGI3hncuc54yXw/+iP3vvWNjX349nWqIA+GTC7eRCTVOJB3eMQzbIqTLpvMYrIcEhj tNBwxj+eSj3V9Zv0gWNVVgqaYhMgLX68P2ODN9XdQ9+lRYxuuMr4hevhhNWuHRBnn52y3SrkxSs6l uqKN10l6nlPE9mTRmBcytAjS+mrFum8jszMocj/cX4l/QGNNC09/Fm8pFxCO5Ub1nWvYUZLCzuw5k vh2Lg16Csw+MyvCETydw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wsM0r-00000008Iij-3ksS; Fri, 07 Aug 2026 14:57:33 +0000 Received: from mgamail.intel.com ([198.175.65.20]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wsM0o-00000008Igy-3jVx for linux-i3c@lists.infradead.org; Fri, 07 Aug 2026 14:57:32 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1786114651; x=1817650651; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=OGrdA5Klzo2kaMa21Wjnl35OoqbyuQ/aauwhgyOink4=; b=d7w1ENIX328fjI0d2jG+sEsvKAS9EFpH/Uffa7IyMr6elPWd9xuKe0Cu z2ZaGVdp2BKXxF1x6P+OIKS2x/JDCCJSFHHYbSARSMKX1VZJH0SXXL4yg Y19L8YE75NRh4k0Y3smm0fF9ir0Y7/nhzejPBpDH3kF9C9Vb7EHY6wOkh LEuJyqnBlJ8jT3fGfcAuJPH70If0iEM7fcRNCJSV7Tiok7BIqTEnMroU7 4GCiPGOWGPFvz+1BfGLMHjlCRqToRtzTel5iYadOtkyC9hHGS9rqQeRh2 ryIrd0bEwLuDwhuJ2XyiwhhChD3eEu1IHfSbSc1sNbbuJlFN6WawnHm2Q w==; X-CSE-ConnectionGUID: ELm6j9KYQvGe6QbWxEflAQ== X-CSE-MsgGUID: GY2aBEZwSVGdY9uRCaxNqA== X-IronPort-AV: E=McAfee;i="6800,10657,11868"; a="86485198" X-IronPort-AV: E=Sophos;i="6.25,210,1779174000"; d="scan'208";a="86485198" Received: from fmviesa008.fm.intel.com ([10.60.135.148]) by orvoesa112.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Aug 2026 07:57:25 -0700 X-CSE-ConnectionGUID: poz2XnVMTzS2a3Ok3YvMQQ== X-CSE-MsgGUID: L4Uac10bShyw1EAGv6GOwg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.25,210,1779174000"; d="scan'208";a="259809885" Received: from amilburn-desk.amilburn-desk (HELO ahunter6-desk) ([10.245.245.114]) by fmviesa008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Aug 2026 07:56:57 -0700 From: Adrian Hunter To: alexandre.belloni@bootlin.com Cc: Frank.Li@nxp.com, akhilrajeev@nvidia.com, mukesh.savaliya@oss.qualcomm.com, rafael@kernel.org, linux-i3c@lists.infradead.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, linux-pm@vger.kernel.org Subject: [PATCH V5 04/14] i3c: master: Fix use-after-free of master->this Date: Fri, 7 Aug 2026 17:56:28 +0300 Message-ID: <20260807145638.168865-5-adrian.hunter@intel.com> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260807145638.168865-1-adrian.hunter@intel.com> References: <20260807145638.168865-1-adrian.hunter@intel.com> MIME-Version: 1.0 Organization: Intel Finland Oy, Registered Address: c/o Alberga Business Park, 6 krs, Bertel Jungin Aukio 5, 02600 Espoo, Business Identity Code: 0357606 - 4, Domiciled in Helsinki X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260807_075730_974057_32019417 X-CRM114-Status: GOOD ( 11.41 ) X-BeenThere: linux-i3c@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-i3c" Errors-To: linux-i3c-bounces+linux-i3c=archiver.kernel.org@lists.infradead.org sysfs attribute callbacks for the master controller device dereference master->this. However, master->this is freed in i3c_master_detach_free_devs() before the master device itself is released. As a result, sysfs accesses can dereference a freed master->this pointer, leading to a use-after-free. Keep master->this alive until i3c_masterdev_release(), which is called after the master device and its sysfs state are being torn down. Do not free master->this as part of the normal device detach path. On the error path in i3c_master_set_info(), reset master->this and bus.cur_master to NULL before freeing the allocated device. Fixes: 3a379bbcea0a ("i3c: Add core I3C infrastructure") Cc: stable@vger.kernel.org Signed-off-by: Adrian Hunter Reviewed-by: Frank Li --- Changes in V5: Added Frank's Rev'd-by Changes in V4: Also reset master->this and bus.cur_master to NULL on the i3c_master_set_info() error path before freeing the allocated device. Tidied up the commit message wording. Changes in V3: New patch drivers/i3c/master.c | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c index abb582645a2e..2357874bb9d6 100644 --- a/drivers/i3c/master.c +++ b/drivers/i3c/master.c @@ -842,6 +842,11 @@ static struct attribute *i3c_masterdev_attrs[] = { }; ATTRIBUTE_GROUPS(i3c_masterdev); +static void i3c_master_free_i3c_dev(struct i3c_dev_desc *dev) +{ + kfree(dev); +} + static void i3c_masterdev_release(struct device *dev) { struct i3c_master_controller *master = dev_to_i3cmaster(dev); @@ -854,6 +859,8 @@ static void i3c_masterdev_release(struct device *dev) i3c_bus_cleanup(bus); fwnode_handle_put(dev->fwnode); + + i3c_master_free_i3c_dev(master->this); } static const struct device_type i3c_masterdev_type = { @@ -1125,11 +1132,6 @@ static void i3c_device_release(struct device *dev) kfree(i3cdev); } -static void i3c_master_free_i3c_dev(struct i3c_dev_desc *dev) -{ - kfree(dev); -} - static struct i3c_dev_desc * i3c_master_alloc_i3c_dev(struct i3c_master_controller *master, const struct i3c_device_info *info) @@ -2266,6 +2268,8 @@ int i3c_master_set_info(struct i3c_master_controller *master, return 0; err_free_dev: + master->bus.cur_master = NULL; + master->this = NULL; i3c_master_free_i3c_dev(i3cdev); return ret; @@ -2286,7 +2290,8 @@ static void i3c_master_detach_free_devs(struct i3c_master_controller *master) i3cdev->boardinfo->init_dyn_addr, I3C_ADDR_SLOT_FREE); - i3c_master_free_i3c_dev(i3cdev); + if (i3cdev != master->this) + i3c_master_free_i3c_dev(i3cdev); } list_for_each_entry_safe(i2cdev, i2ctmp, &master->bus.devs.i2c, -- 2.53.0 -- linux-i3c mailing list linux-i3c@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-i3c