From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793212260; b=tNbIMfORXvsfVTmYbrxbhUJWZ06B02KHRLwsMbcpuxSEaqzCUsCc6P/BxQgOLu7zbV8f IfxNegS1t/yULuP+3AKIfqXcPXmOS7J+I7pb+bIt7cJLuDblgiUuTKYAPbLjbybt0ZLRV pXq0BOKMJGlbOwkky8XOGrzeIMPisV/HzhX0MDY4f7hUm5uz0327ECgz4KSWcHzwMjGhd DMZW/81eNAM36YtjPXZeloexzH4VEN6gVcMsfmEQUvNzqEG/Vg3mMr4RlAAjQ13ADiaJ9 KnZjtNAS0TOdqnyTaFE3dh7piw4+/uXRDeEWbdfD6LfC3mH3OzG9sI8wTf7rB6Bc/dg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793212260; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Type:Content-Transfer-Encoding; bh=SCxmg0JLIEwV4z4NG+tRqcLF7Q/WdAmxKAMZHJT6LJ4=; b=17l5bg2+E4z2CKwD/swcLNQza+UdoYSOcbvBs8P1kclRahURpT+j12hfmTywAHGn7tXK JbpaUUPX0g+Iln01FYPPKKkHrrQgX1QUARL7FzZHykTr3WZwQ4Z9wLepiVgHcdfzzTzoP MFvXVs/H+ILVBw/H/5HK/9SW1ZiU4iD6NNSwijz/DGzbE2IepmknnlZEqGO9wz5MItCXv aTYqwiQRu9W/PnNmk/nYNScKk4up6qA8ILPOHW+5cvVj+MFr5PVRGBWLIxOgetLCF8yeT UqBXK8WXa9Ns2xaARoRXEUIEMtVF46ChAXJopAVK0wGBFQVpAE/+2PqqEkKcvp8WO+Q== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b="c/U5OBW7"; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6E46A606A31C; Wed, 28 Oct 2026 18:31:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=c/U5OBW7 Received: by smtp.kernel.org (Postfix) with ESMTPSA id BF0781F01825; Wed, 28 Oct 2026 18:30:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1793212260; bh=SCxmg0JLIEwV4z4NG+tRqcLF7Q/WdAmxKAMZHJT6LJ4=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=c/U5OBW7tXL7GAYgAGK/iMpoTLD50atH9KWD1e03Ley3xLX2/0VOh9/zvq3A0J/Bn 9Byt7sfTz5fHFvbyY0x0KdSRZx+uk0tcq4CKD6wlq8U9NozFok+8tG3WoJuVRMSnXx nw8irnu33TqdQF0wzHpIkcknAXDy3b6UbpMTCfk8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Adrian Hunter , Frank Li , Alexandre Belloni , Sasha Levin Subject: [PATCH 6.1 0093/1887] i3c: master: Fix use-after-free of master->this Date: Wed, 28 Oct 2026 17:36:29 +0100 Message-ID: <20261028170501.349773936@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261028170459.200466217@linuxfoundation.org> References: <20261028170459.200466217@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: patches@lists.linux.dev List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Adrian Hunter [ Upstream commit feb0ed76601f3c2f91f08688c5a7d8b9d382f720 ] 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 Link: https://patch.msgid.link/20260807145638.168865-5-adrian.hunter@intel.com Signed-off-by: Alexandre Belloni [ retained of_node_put(dev->of_node) instead of upstream’s fwnode_handle_put(dev->fwnode). ] Signed-off-by: Sasha Levin --- 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 d0f5ae21ea1f3..cbc3f2d24b618 100644 --- a/drivers/i3c/master.c +++ b/drivers/i3c/master.c @@ -667,6 +667,11 @@ 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); @@ -679,6 +684,8 @@ static void i3c_masterdev_release(struct device *dev) i3c_bus_cleanup(bus); of_node_put(dev->of_node); + + i3c_master_free_i3c_dev(master->this); } static const struct device_type i3c_masterdev_type = { @@ -866,11 +873,6 @@ 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) @@ -1738,6 +1740,8 @@ 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; @@ -1758,7 +1762,8 @@ 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